so cool it doesn't need sprague's or bands to work a weaker part in turbo 400's and 727 transmission as the the 70's big power car's ended up eating them like candy 🍬 yes the aftermarket is backing this transmission well enough to get used as swap's and or hot rod'ed/modified from OEM/dealership's configurations
Too bad vehicle manufacturers rate it as lifetime fluid transmission. Tere should be a provision to make fluid changes easier. I burned the crap out of my hand when doing so.
I've been following you for a long time & each time BARELY grasping how the transaxle operates. I thought nothing will top that 9HP transaxle in your last video, but those ZF boffins actually managed to top even that insanity. Now I'm reminded why I'm a Sociology & not an Engineering major. Kudos & thanks for this in-depth tour of this engineering masterpiece.
Amazing transmission. I've driven several cars with these, most notable being a Giulia Quadrifoglio. It's buttery smooth when you're driving normally and crazy fast and responsive in race mode. The people that design these are on another level of intelligence.
A fascinating demonstration! I'm in awe at your knowledge and skills with transmissions, it amazes me how these things are designed, very clever engineers indeed 🤓
I own a 2021 Jeep Wrangler Rubicon and it uses the 2nd generation ZF8 and it is arguably one of the smoothest and best performing transmissions currently on the market. The ones in non-V8 FCA (Chrysler) vehicles are actually made right here in the states since ZF gave FCA the license to produce the 8HP50 under their trademarked name Torqueflite 8 - 850RE. However, for all their diesel and V8 vehicles, FCA still buys the 8HP75 (the second generation of the 8HP70 shown in your great video) from ZF in Germany. This is the first time I have seen an expert actually demonstrate all the internal gearing and mechanisms of the ZF8, and in such great detail. Thank you for your work professor.
Because my dad recently got a new car with this 8-spd transmission, I became curious about auto transmissions in general. Let's just say that small curiousity costed me many many hours of deep diving into internet before I could find anything that was enough in-depth and not too focused on math. With this video I'm finally starting to understand. So thanks!
Thanks for the great video. When I was growing up , I studied 2 speed Powerglides, Ford C4’s and Chrysler Torqueflights. All these are very simple and easy to understand. Boy, have the times changed. I have the ZF 8 speed in our Grand Cherokee. Indeed it is a remarkable design. Shifts as smooth as butter.
Great info. When Chrysler introduced this transmission series I took a 2 day training class of disassembly and reassembly. The instructor stressed do not repeat do not lay the transmission on its side and drag the parts out onto the bench. Use the square box stand used for the g56 trans. Stand it up at all time. Dragging the parts out and falling onto the bench will distort the steel drums. A guy in my class drug the parts out onto the bench. Damaged a drum. That class has been changed to a 1 day service class. Only component we at the dealership can replace is valve body and external seals.
What a blessing to live in an age when we have the expertise of men like professor Kelly's literally at our fingertips! Fascinating......that was a very fast 26.5 minutes; seemed a lot shorter.
Good grief! This is amazing! Who designs this stuff and who can figure out how it works? Rhetorical questions, but still, to a non-mechanic like myself it's totally astounding. So cool. This video is a great example of the good part of the Internet. Anything you want to learn about, you can experts like this to education and explain. Thanks for posting!
This is exactly why the first thing I did when I bought my 535i XDrive I ordered a ZF kit (Pan, Bolts, Plug, Fluid) and I will be changing the fluid again after another 100 miles. Change it every 50,000 miles folks. For reference, the car has 123,000 miles.
Thank you so much for your vids. I'm doing a individual project according to the ZF transmission to come up with an idea to make this even more efficient. So those video's seriously helped me get to know the transmission a bit more!
I bought a car with this tranmission recently. So I decided to watch some video to figure out how it works only to fullfill my curioisity. I watched this video from the first second to the last. And I realised I didnt understant single bit of it. Technology nowadays... It must be designed by some crazy scientist!
The transmission is very simple as the mister said. All gear sets interact with each other to provide 8 gear ratios. To develop this gear sets they actually used a supercomputer to calculate the rate at which these gears sets are moving. Mechanically its a very simple and repairable transmission if attended by a specialist of course.
I was looking this up as the new 2019 Toyota Camry I purchased, has a 8 speed automatic transmission. I stayed and watched the whole video. Impressive. Thanks.
Thanks so much for the quick response! I just contacted an independent shop with a good reputation. $770!! Apparently the fluid is $25/liter and $130 for the gasket and about$130 for the filter! All OEM parts and supplies. Good God! I still will get it done but wow!
This is why I love RUclips. If this ever made it to tv back in the day, for it to be palatable to the general public it would have to be edited down to something that would offer no educational value. Sometimes you just feel like knowing EVERYTHING about something :-)
I am new to the automotive industry as a transmission controls engineer. I couldn't express how excited I was when I saw your videos on the actual demonstration of these transmissions that I deal with everyday. THANK YOU for all the hard work you shared with us! But I would like to expect if by any chance you can talk about the hydraulics part of the transmission in the future.
I know how engines work, and have worked on small engines, even taking some apart, but when it comes to transmissions, I'm completely lost! I have the ZF 8HP75 on my Jeep. Smooth shifting transmission!
Apparently FCA builds versions of these transmissions on their own, using an agreement with ZF. They then rename them with their own conventions (for example, my Jeep Wrangler has the 850RE), change the gear ratios, and write their own software to control them. So, if you buy a FCA vehicle, you aren't necessarily getting a 100% actual ZF transmission. Many people have found that the FCA versions are clunky and have several problems, many of which FCA has attempted to cure with software updates.
WeberAuto There’s a serious flaw in these 8HP70’s supposedly built by FCA, in that shifting 1>2 first time each day after an overnight rest causes a delayed shift and surge into 2nd gear, speculation on causes vary from a leak down of fluid from the clutch C or E piston, to poor software control, but seeing as it’s only after that first drive off each day, most likely it’s a leak, is there any way you could look into this and do a video on how this might occur and a possible fix? One theory may be a bad o-ring and the other is that the fluid level is too low, even when filled correctly via procedure, and the leak down may be due to a break or gap in fluid continuity between the path to the clutch piston and the pan fluid level, allowing it to vacate the piston and be replaced with air in a slow overnight process which then is repopulated once the clutches are engaged again. If FCA have changed the fluid level requirements from the original design due to 4x4 needs as to not act as over filled on steep inclines and therefore reduced the full capacity, this may be the reason for the initial one-off poor shift as that would be the time it’s at its lowest level and allow a leak down over time. Your thoughts? Would you be interested in looking into it? Thanks in advance for your input.
I have a Ram 1500, and I may have issues with my transmission. I still think the 8 speed design is awsome! This is great information, and a great video.
Great video. This transmission is indeed a dream, when it's working perfectly. Mine started to slip a bit in 150K miles. Oil never changed. BMW claims that no change is needed, LOL. So indeed they completely changed the seals and connection of the valve body to transmission. I can't find any info about the bridge seal, tube seals etc found in the 6HP version. I am tempted to change oil on mine and want to make sure all those easy to replace rubbers are changed at the same time.
Beautiful engineering and metal work. And still absolutely unfathomable after your take down. Odd idea to change the entire pan for a filter, but a miracle that it has a means to check the level without a 20 page guide and a thermometer
Well done sir! Excellent video. Another engineering triumph is the electrified version of this transmission. ZF have some wizards designing these things.
As always John, you did a great job. I commend your teaching ability. It is truly exemplary dear person. I will continue to strive to learn HOW it works. But due to its complexity, that may be a long time. Keep up the excellent work John.
It is a very widely applied transmission from very little powered 120i of BMW all the way to something like the BMW M760LI or RR. It is certainly a very complicated device, well engineered just like its predecessor 6HP. I like the fact that it reacts almost like a gearless and keeps the Rev really low when cruising. I was lucky to have chances drove both 2008 BMW x3 and 2011 BMW x3, in both car it has the same engine(N52) and pretty much the similar shaft or cv joint except 2008 is 6HP while 2011 is 8HP. The amazing part is how low the Rev at 120Km/h, only 1900RPM compare to 2008 at roughly 3000RPM. That is enough to consider a possible fuel saving without doing too much modification. Of course with a turbocharged straight 6 on the 35i later in the series dropped it all the way down to just 1500RPM in a non-climbing situation. The other benefit is engine brake, though not a dedicated engine brake like trucks but with more gear, I get to select more braking resistance in wider range compare to the 6 speed where I can over shifting and it will prevent me from receiving such resistance. The other thing I found maybe not subject to just the transmission but it might be linked as well. it has lower resistance in its system when coasting in which the car can hold a speed much longer, sometimes in a few blocks on the road when I get to the speed of the traffic, doesn't has to be fast and 60km/h is more than enough, I can just coast the remaining distance to the traffic light without engaging either accelerator nor brake. After no doubt, I would choose another X3 but maybe the diesel version this time, still with the 8HP possibly.
I have a 2013 awd Charger that i needed the transmission replaced in. I loved the video and plan on taking the transmission home with me when they are done so I can tare it done to she this in person! Amazing design!!!
Wait - so the ZF 9HP, a transmission with more gears (g. ratios), was easier to diagram and convey than this 8HP? How does that work? XD Great work-up as usual. Thank you!
Did you know that this ZF transmission appears to be the best vehicle transmission in the world (in terms of comfort, efficiency, power, speed etc). BMW started using those in 2010. In 2016 they thought they will have another box with either 9 or 10 gears (cant recall) with the next generation but skipped because this gearbox is just that good. Now 2017 BMW still use this gearbox with 8 speeds. I've driven it. It's perfect everywhere. Including autobahn at 250km/h. With 6cyl diesel BMW at 100km/h it keeps engine around 1800rpm. At 200km/h around 3600rpm. This gearbox clearly keeps the engine always in ideal rpm range for that specific speed+dragload. Interesting fact that at 250km/h speed 7th gear is used. At slightly lower speed 8th gear is selected.
Yes, it is possible. But it is also possible that your throttle angle is too high at that speed due to the engine load. Too high of an engine load can prevent top gear.
WeberAuto I'm not sure what throttle angle is? Required power vs maximum power at that specific rpm? Max power according to dyno graph is around 4000rpm and then starts to fall. Both 7th and 8th gear are above 4000rpm.
Arnis Tarassu Yes, but the engine is at :less: of a mechanical advantage in 8th gear, compared to 7th. The engine may be producing more torque, but there is less torque at the wheels because the engine is making less rotations compared to the output shaft in 8th rather than 7th.
An excellent video as always. It does look like rocket science in action but it is very simple in practice. Thank you for your efforts, very interestingly shown.
Let's see a inspection video of all components including clutch drums, spag rotation. Clutch wear, bushing wear, pump, failure points, application charts, and lets not forget converter application. Love your video to by the way.
After driving a 1998 Dodge Intrepid for many years, in 2012 I was looking at a 2013 Dodge Charger. I'd been dealing with transmission issues for some time, so was concerned about an *eight* speed transmission, wondering if Chrysler could get something so complicated right? I was nervous. But when I went to the dealership and looked at the car, I saw on the window sticker re: the transmission "Made in Germany", there was an audible sigh heard throughout the land :-)
Thanks to John at Weber Auto, excellent presentation material as usual. Interesting design of the outer drive drums - reminds me of a giant Starrett hole saw cutter, except this application has drive teeth rather than cutting teeth. Those outer drums could have a useful afterlife life when salvaged as some sort of colanders or deep fat friers in a fast food kitchen! (-;
Dear professor Kelly , thankyou for this mind blowing education, on this awesome transmission , im with you on seeing and understanding the power flow up to the point of complication and confusion ,of not being able to visually see it , never the less, we know it works , i wonder if i could suggest the complication of a centerline dissection for the full internal explanation , re , cut it in half . i bet your students , colleges and yourself and perhaps even zf themselves , would go for it . zf may already have one to donate or loan ,however ,just my technical thoughts i love to share with you , thanks again ,from, Peter Foote ,Australia . diesel mech .
Hello Weberauto, I just bought a 2016 Charger V6. so I guess this is what transmission I have on my car. I guess it is good that I have a lifetime warranty through my dealer in the powertrain because I bet it can get expensive for trans maintenance say 5 years from now for this specific transmission.
Wanted to up the power on the EcoDiesel, but if the transmission only handles 700 at the input shaft I either need to seriously beef the 8HP70 up or see if my 1500 can take the 8HP90. Very well put together transmission. Enjoyed your video!
The best transmission. I had a ZF8 in an Audi A7. I’ve tried this transmission in Chrysler products and it seemed to be programmed much lazier than the the high speed / high precision set up in new turbo BMWs.
Thanks very much. I have a Jeep 2015 G C Overland 3 litre diesel RHD with 120,000km using this 8 speed transmission. Gear changes on auto are very smooth. Computer does a great job, even introducing engine breaking on a long down hill run. I worry about repair cost if something goes wrong, but I treat it with care. I would like to know more on the control of the gear box.
apologize, we have some problems with lnternet and youtube not availble here, in Iran, oh, governers filteration we have some words to thanksgiving a teacher, people balive one of holy man has said that; I will serve all my life who that teach me just one word!! I learn more from you videos thank you
I have learned so much about automatic transmissions through watching your videos, so thank you very much for posting everything up and being as detailed as you have been. I was wondering if you knew anything about the VW 01M transmissions? I have had experience of them (not a great one, I'll tell you!) and it took a while for the issues to be identified and sorted out. That car has gone, but I still never understood why the transmission was so poor (it seems many others have had hard-to-diagnose problems with them, surrounding hard shifts after everything has warmed up - say 20 minutes of driving)
Hi, thank you for your kind words. I have not had any experience with the VW 01M transmission. Hopefully, I will get some in the future, but we do not do much VW works at our school. Best wishes!
Have you thought about Cutting windows into those 'shells' such that you could still point and spin or hold clutches/sun gears so you could show the power flow for each gear ? Windows would allow you to touch/hold parts and be able to see them for illustration purposes. Thanks for presentation !!
It's easier to view power flow through the 8HP70/90 if you have a model loaded to Catia or SolidWorks. You have to be within ZF's supplier network to get that though.
The best and most efficient plus cheapest and simplest powertrain for both ICEs and EVs is the Positive Drive Infinitely Variable Transmission, PDIVT. The power transmission starts from the center of input shaft and shifts ouwards as the vehicle has gaining more speed. It offers what CVT can do but in positive drive. And starting from center of input shaft. This is the best solution for heavy vehicles such as trucks, buses as well as hypercars, sedans and motorcycles. The world needs innovation and breakthrough in technologies. Make a change if we care about emissions and global warming. Because the PDIVT powertrain will greatly improve the efficiency of transmitting power from engines to wheels. And this will save fuel and energy causing less emissions issues.
nice explanation, it seem those sleeves that transfer power won't hold up if they can be deformed with a screwdriver, but I guess the engineers know what they are doing, I have a v6 ram with zf8hp45, sometimes get a hard 1-2 shift but otherwise very smooth transmission,
So I have a 22 Wrangler with the ZF 8Sp. Several Jeep owners have been experience a whirring sound (sounds like a bearing) at low gears (1st and 2nd), nothing seem to be out of wack. Vehicle is driving fine. Is that a normal characteristic of the ZF transmission?
Then a few years later they refine this into the second Generation, another few pounds lighter, smaller and stronger. My car has the ZF 6HP, my mom's car has the same one as your described.
They need a better transmission fluid for these transmissions, on the Amsoil video by Eben he shows the cold pour test and Mopar ZF 8&9 transmission fluid is like and ice cube below 32°f. It seems like that some one would burn transmission up trying to drive in the colder months.
I disagree with the notion that the valve body cannot be easily serviced, but the rest is spot on. Excellent content clearly explained. Are there additional shims and/or thrust bearings used here and there, or just the one thrust bearing?
we also have this transmission in a ram 1500 4wd/hemi. it really is an amazing piece of engineering, and its great to see the internals even though i dont understand most of it!! driving with it is seamless, ty[ically 3 shifts before you cross an intersection from a red light and then on the otherhand it also preforms flawlessy towing our 8000 lb travel trailer up the steepest and longest of hills. if you know, could you explain what happens in "tow/haul" mode and when we should be using the manual shift buttons
Hi I’m working on a 8hp65 there is fluid coming out of the side of the trans fluid towards the back. I took the transfercase filler plug out and a bunch of fluid came out. Is there a seal that keeps the trans and transfercase separated?
I have a 2018 B9 Audi S4 with the 8HP65. How important do you think it is that we use “approved ATF fluid?” Their is some talk of liqui Moly 1800 being suitable for this transmission, I honestly don’t believe that. I highly recommend ZF LifeGuard 8 which is designed for this complex transmission. Do you think people would be causing premature wear/damage using any fluid other than ZF etc.? Thanks! Amazing video! This transmission is INSANE, I am tuned, and it’s just incredible this transmission is able to increase shift speed and response with tuning just amazing ZF does have the most advanced Torque Converter Transmission in the world.
Ive got a 2017 durango sxt awd with the 845re and its a piece. Getting its 3rd valve body installed now. I doubt that the problem though. P0733 code rough 3-4 shift that jerks your head.
The NAG1 has been here since 2005 in Chryslers, even longer in Mercedes; it has been very reliable. The ZF 8HP has been here since 2013 with very few issues. time will tell.
nice video! sucks the way they are creating these now days where you cannot get replacement parts for the value bodies and the pan is the fliter... im sure a full assembly is not cheap and that filter pan is more than just a plain old tran fliter plus no dipstick makes it harder for an owner to service their own vehicle.. its great for builders and companies . ..
Hands down the best transmission in the world right now. Amazing shift quality and speed especially if you map it with xhp.
Thanks for watching
so cool it doesn't need sprague's or bands to work a weaker part in turbo 400's and 727 transmission as the the 70's big power car's ended up eating them like candy 🍬
yes the aftermarket is backing this transmission well enough to get used as swap's and or hot rod'ed/modified from OEM/dealership's configurations
ZF 8 speed has a high failure rate
@@scottchila7284 Show me the Data. We want FACTS son.
Too bad vehicle manufacturers rate it as lifetime fluid transmission.
Tere should be a provision to make fluid changes easier. I burned the crap out of my hand when doing so.
I've been following you for a long time & each time BARELY grasping how the transaxle operates. I thought nothing will top that 9HP transaxle in your last video, but those ZF boffins actually managed to top even that insanity.
Now I'm reminded why I'm a Sociology & not an Engineering major. Kudos & thanks for this in-depth tour of this engineering masterpiece.
+Trades46 Thank you very much!
Amazing transmission. I've driven several cars with these, most notable being a Giulia Quadrifoglio. It's buttery smooth when you're driving normally and crazy fast and responsive in race mode. The people that design these are on another level of intelligence.
Thanks for watching
Had to pause this video several times just to rack my head around exactly what was going on with power flow! Incredible engineering and explanation!
Thank you!
A fascinating demonstration! I'm in awe at your knowledge and skills with transmissions, it amazes me how these things are designed, very clever engineers indeed 🤓
I own a 2021 Jeep Wrangler Rubicon and it uses the 2nd generation ZF8 and it is arguably one of the smoothest and best performing transmissions currently on the market. The ones in non-V8 FCA (Chrysler) vehicles are actually made right here in the states since ZF gave FCA the license to produce the 8HP50 under their trademarked name Torqueflite 8 - 850RE. However, for all their diesel and V8 vehicles, FCA still buys the 8HP75 (the second generation of the 8HP70 shown in your great video) from ZF in Germany. This is the first time I have seen an expert actually demonstrate all the internal gearing and mechanisms of the ZF8, and in such great detail. Thank you for your work professor.
Thank you very much
Because my dad recently got a new car with this 8-spd transmission, I became curious about auto transmissions in general.
Let's just say that small curiousity costed me many many hours of deep diving into internet before I could find anything that was enough in-depth and not too focused on math.
With this video I'm finally starting to understand. So thanks!
+André Smith Thank you!
Archaeologists finding one of these transmissions a thousand years from now will think it was a timepiece
Mr.Kelly your lectures are awesome and this one is no exception. You are a really good lecturer. Thank You very much for this and the other lectures.
+Kaktus Jack Thank you!
Thanks for the great video. When I was growing up , I studied 2 speed Powerglides, Ford C4’s and Chrysler Torqueflights. All these are very simple and easy to understand. Boy, have the times changed. I have the ZF 8 speed in our Grand Cherokee. Indeed it is a remarkable design. Shifts as smooth as butter.
Thanks for your feedback, we have 9 and 10 speeds now
Great info. When Chrysler introduced this transmission series I took a 2 day training class of disassembly and reassembly. The instructor stressed do not repeat do not lay the transmission on its side and drag the parts out onto the bench. Use the square box stand used for the g56 trans. Stand it up at all time. Dragging the parts out and falling onto the bench will distort the steel drums. A guy in my class drug the parts out onto the bench. Damaged a drum. That class has been changed to a 1 day service class. Only component we at the dealership can replace is valve body and external seals.
Thanks for your feedback! Some people are not ready for detailed transmission work, it can take years of training and a lot of patience.
Awesome video instruction. If ZF makes as good an automatic as their manual transmissions, this should be one excellent transmission.
+Scott Weatherman Thank you!
Then they made the 9 speed aaaaaand.....meh...
What a blessing to live in an age when we have the expertise of men like professor Kelly's literally at our fingertips! Fascinating......that was a very fast 26.5 minutes; seemed a lot shorter.
Good grief! This is amazing! Who designs this stuff and who can figure out how it works? Rhetorical questions, but still, to a non-mechanic like myself it's totally astounding. So cool. This video is a great example of the good part of the Internet. Anything you want to learn about, you can experts like this to education and explain. Thanks for posting!
This is exactly why the first thing I did when I bought my 535i XDrive I ordered a ZF kit (Pan, Bolts, Plug, Fluid) and I will be changing the fluid again after another 100 miles. Change it every 50,000 miles folks. For reference, the car has 123,000 miles.
Amazing explanation , thank you so much for your work trying to make everyone understand this engineering marvel!
Thank you so much for your vids. I'm doing a individual project according to the ZF transmission to come up with an idea to make this even more efficient. So those video's seriously helped me get to know the transmission a bit more!
+GetThe JobDone Thank you! I am glad it was helpful
Let's appreciate this marvel of engineering. Thanks John for the great video.
Thanks for watching!
I understood 3% of what you said.
But it's fascinating to watch the engineering of this transmission design.
Great detailed description 👌
I bought a car with this tranmission recently. So I decided to watch some video to figure out how it works only to fullfill my curioisity. I watched this video from the first second to the last. And I realised I didnt understant single bit of it. Technology nowadays... It must be designed by some crazy scientist!
+bilibiliism I agree!, Thanks for watching!
they're called Germans
Those crazy scientistes are Germans! And may God bless them! I have the same transmission in my BMW f 34 GT 2015 ! Great transmission just wooow!!
As usual the credit goes to the Germans.
The transmission is very simple as the mister said. All gear sets interact with each other to provide 8 gear ratios. To develop this gear sets they actually used a supercomputer to calculate the rate at which these gears sets are moving. Mechanically its a very simple and repairable transmission if attended by a specialist of course.
Incredible video! Helped me a lot to understand the gearsets' design of this transmission. Thanks from Russia!
Thank you!
I was looking this up as the new 2019 Toyota Camry I purchased, has a 8 speed automatic transmission. I stayed and watched the whole video. Impressive. Thanks.
your camry likely is rocking Aisin 8 speed which is probably most reliable in the world! Not ZF
Best automatic transmission on the market today, but they scare the shit out of me. Thank god for extended warranties.
Why you say that? The zf’s are reliable.
Thanks so much for the quick response! I just contacted an independent shop with a good reputation. $770!! Apparently the fluid is $25/liter and $130 for the gasket and about$130 for the filter! All OEM parts and supplies. Good God! I still will get it done but wow!
+pchansen100 Wow, that is expensive! Still, it is less than a new transmission. Best wishes.
This is why I love RUclips. If this ever made it to tv back in the day, for it to be palatable to the general public it would have to be edited down to something that would offer no educational value.
Sometimes you just feel like knowing EVERYTHING about something :-)
I am new to the automotive industry as a transmission controls engineer. I couldn't express how excited I was when I saw your videos on the actual demonstration of these transmissions that I deal with everyday. THANK YOU for all the hard work you shared with us! But I would like to expect if by any chance you can talk about the hydraulics part of the transmission in the future.
+Adam Zhang Thank you for your feedback! I would like to do hydraulics at some time in the future.
Amazing transmission! Even more amazing explanation on such a complex machine, thanks!
Glad you liked it!
I know how engines work, and have worked on small engines, even taking some apart, but when it comes to transmissions, I'm completely lost!
I have the ZF 8HP75 on my Jeep. Smooth shifting transmission!
It is a good transmission
Apparently FCA builds versions of these transmissions on their own, using an agreement with ZF. They then rename them with their own conventions (for example, my Jeep Wrangler has the 850RE), change the gear ratios, and write their own software to control them. So, if you buy a FCA vehicle, you aren't necessarily getting a 100% actual ZF transmission. Many people have found that the FCA versions are clunky and have several problems, many of which FCA has attempted to cure with software updates.
True, Thanks for your feedback
WeberAuto
There’s a serious flaw in these 8HP70’s supposedly built by FCA, in that shifting 1>2 first time each day after an overnight rest causes a delayed shift and surge into 2nd gear, speculation on causes vary from a leak down of fluid from the clutch C or E piston, to poor software control, but seeing as it’s only after that first drive off each day, most likely it’s a leak, is there any way you could look into this and do a video on how this might occur and a possible fix? One theory may be a bad o-ring and the other is that the fluid level is too low, even when filled correctly via procedure, and the leak down may be due to a break or gap in fluid continuity between the path to the clutch piston and the pan fluid level, allowing it to vacate the piston and be replaced with air in a slow overnight process which then is repopulated once the clutches are engaged again.
If FCA have changed the fluid level requirements from the original design due to 4x4 needs as to not act as over filled on steep inclines and therefore reduced the full capacity, this may be the reason for the initial one-off poor shift as that would be the time it’s at its lowest level and allow a leak down over time.
Your thoughts? Would you be interested in looking into it? Thanks in advance for your input.
Once again a very good explanation on Transmissions.
Thank you!
I was a big torqueflite guy back in the day. Great video.
Thank you
Thank you for that clear explanation. You're truly a great teacher.
I could listen to this guy talk about anything all day
I have a Ram 1500, and I may have issues with my transmission. I still think the 8 speed design is awsome! This is great information, and a great video.
Thank you for your feedback!
I hear is bad in the ram 2500 too. That’s why I’m doing a little research 🤔
Great video. This transmission is indeed a dream, when it's working perfectly. Mine started to slip a bit in 150K miles. Oil never changed. BMW claims that no change is needed, LOL. So indeed they completely changed the seals and connection of the valve body to transmission. I can't find any info about the bridge seal, tube seals etc found in the 6HP version. I am tempted to change oil on mine and want to make sure all those easy to replace rubbers are changed at the same time.
Beautiful engineering and metal work. And still absolutely unfathomable after your take down. Odd idea to change the entire pan for a filter, but a miracle that it has a means to check the level without a 20 page guide and a thermometer
Amazing German engineering.... very good explanation.
Well done sir! Excellent video. Another engineering triumph is the electrified version of this transmission. ZF have some wizards designing these things.
Thanks for watching
As always John, you did a great job. I commend your teaching ability. It is truly exemplary dear person.
I will continue to strive to learn HOW it works. But due to its complexity, that may be a long time.
Keep up the excellent work John.
+pat dee Thank you very much!
It is a very widely applied transmission from very little powered 120i of BMW all the way to something like the BMW M760LI or RR. It is certainly a very complicated device, well engineered just like its predecessor 6HP.
I like the fact that it reacts almost like a gearless and keeps the Rev really low when cruising. I was lucky to have chances drove both 2008 BMW x3 and 2011 BMW x3, in both car it has the same engine(N52) and pretty much the similar shaft or cv joint except 2008 is 6HP while 2011 is 8HP. The amazing part is how low the Rev at 120Km/h, only 1900RPM compare to 2008 at roughly 3000RPM. That is enough to consider a possible fuel saving without doing too much modification. Of course with a turbocharged straight 6 on the 35i later in the series dropped it all the way down to just 1500RPM in a non-climbing situation.
The other benefit is engine brake, though not a dedicated engine brake like trucks but with more gear, I get to select more braking resistance in wider range compare to the 6 speed where I can over shifting and it will prevent me from receiving such resistance.
The other thing I found maybe not subject to just the transmission but it might be linked as well. it has lower resistance in its system when coasting in which the car can hold a speed much longer, sometimes in a few blocks on the road when I get to the speed of the traffic, doesn't has to be fast and 60km/h is more than enough, I can just coast the remaining distance to the traffic light without engaging either accelerator nor brake.
After no doubt, I would choose another X3 but maybe the diesel version this time, still with the 8HP possibly.
Thanks for your feedback
I love Automatic Transmission Car. Thank you Sir.
Thank you!
I have a 2013 awd Charger that i needed the transmission replaced in. I loved the video and plan on taking the transmission home with me when they are done so I can tare it done to she this in person! Amazing design!!!
Wait - so the ZF 9HP, a transmission with more gears (g. ratios), was easier to diagram and convey than this 8HP? How does that work? XD
Great work-up as usual. Thank you!
+GammaCruxis Thank you!
Excellent!!!))) One of the best videos I have seen...
Did you know that this ZF transmission appears to be the best vehicle transmission in the world (in terms of comfort, efficiency, power, speed etc).
BMW started using those in 2010. In 2016 they thought they will have another box with either 9 or 10 gears (cant recall) with the next generation but skipped because this gearbox is just that good. Now 2017 BMW still use this gearbox with 8 speeds.
I've driven it. It's perfect everywhere. Including autobahn at 250km/h.
With 6cyl diesel BMW at 100km/h it keeps engine around 1800rpm. At 200km/h around 3600rpm. This gearbox clearly keeps the engine always in ideal rpm range for that specific speed+dragload.
Interesting fact that at 250km/h speed 7th gear is used. At slightly lower speed 8th gear is selected.
Awesome information! Thanks for the feedback.
WeberAuto is it possible that the maximum torque in 8th gear is limited (due to clutch?) and can't be used while cruising at 250kmh?
Yes, it is possible. But it is also possible that your throttle angle is too high at that speed due to the engine load. Too high of an engine load can prevent top gear.
WeberAuto I'm not sure what throttle angle is? Required power vs maximum power at that specific rpm?
Max power according to dyno graph is around 4000rpm and then starts to fall. Both 7th and 8th gear are above 4000rpm.
Arnis Tarassu Yes, but the engine is at :less: of a mechanical advantage in 8th gear, compared to 7th. The engine may be producing more torque, but there is less torque at the wheels because the engine is making less rotations compared to the output shaft in 8th rather than 7th.
I am in the development of 8HP/9HP/7DT/8DT and these transmission are really marvleous 🙂
That s a proper mechanic hand cleaning procedure!!!!
Amazing explanation, this kind of complex technology fascinate me... awesome mechanics engineering... thank you so much John...
An excellent video as always. It does look like rocket science in action but it is very simple in practice. Thank you for your efforts, very interestingly shown.
Don't know why I enjoyed the video this much 😁
Really Amazing to see this design...Incredible effort @john 😊
Let's see a inspection video of all components including clutch drums, spag rotation. Clutch wear, bushing wear, pump, failure points, application charts, and lets not forget converter application.
Love your video to by the way.
After driving a 1998 Dodge Intrepid for many years, in 2012 I was looking at a 2013 Dodge Charger. I'd been dealing with transmission issues for some time, so was concerned about an *eight* speed transmission, wondering if Chrysler could get something so complicated right? I was nervous.
But when I went to the dealership and looked at the car, I saw on the window sticker re: the transmission "Made in Germany", there was an audible sigh heard throughout the land :-)
Vi have in Sweden. You are a good teacher.🙂
Thank you!
Thanks to John at Weber Auto, excellent presentation material as usual. Interesting design of the outer drive drums - reminds me of a giant Starrett hole saw cutter, except this application has drive teeth rather than cutting teeth.
Those outer drums could have a useful afterlife life when salvaged as some sort of colanders or deep fat friers in a fast food kitchen! (-;
+celtichongy Thanks for the nice comments and feedback! They do look like giant colanders!
Wow! I am totally impressed with your knowledge and ability to educate. I am also wowed by this ecomplex beast. Excellent knowledge transfer! Bill
Dear professor Kelly , thankyou for this mind blowing education, on this awesome transmission , im with you on seeing and understanding the power flow up to the point of complication and confusion ,of not being able to visually see it , never the less, we know it works , i wonder if i could suggest the complication of a centerline dissection for the full internal explanation , re , cut it in half . i bet your students , colleges and yourself and perhaps even zf themselves , would go for it . zf may already have one to donate or loan ,however ,just my technical thoughts i love to share with you , thanks again ,from, Peter Foote ,Australia . diesel mech .
i wouldve loved to see the electric assist drive installed with it. awesome demo either way!
Fascinating! I love your videos, thank you!
+Scott Simon Thank you!
Thank you very valuable information. Makes me want to attend your classes.
Hello Weberauto, I just bought a 2016 Charger V6. so I guess this is what transmission I have on my car. I guess it is good that I have a lifetime warranty through my dealer in the powertrain because I bet it can get expensive for trans maintenance say 5 years from now for this specific transmission.
+Acuravigor47 Thanks for the feedback, that is good to know!
Wanted to up the power on the EcoDiesel, but if the transmission only handles 700 at the input shaft I either need to seriously beef the 8HP70 up or see if my 1500 can take the 8HP90. Very well put together transmission. Enjoyed your video!
Thank you!
The best transmission. I had a ZF8 in an Audi A7. I’ve tried this transmission in Chrysler products and it seemed to be programmed much lazier than the the high speed / high precision set up in new turbo BMWs.
Interesting, thanks for the feedback!
I wonder if ECM programming is done per manufacturer hmm
thank you john for good job .
+crist john Thank you!
Thanks very much. I have a Jeep 2015 G C Overland 3 litre diesel RHD with 120,000km using this 8 speed transmission. Gear changes on auto are very smooth. Computer does a great job, even introducing engine breaking on a long down hill run. I worry about repair cost if something goes wrong, but I treat it with care.
I would like to know more on the control of the gear box.
Wow ! And I thought I was smart for changing my own fluid.. Yes it's an incredible tech marvel that works awesome in my Jaguar F-Type.
Hello I am actually having some serious trouble with my zf8 hp70 I was wondering if you could and be willing to throw some suggestions at me.
Good demonstration. Thanks
+Jim Buford Thank you!
Aliens design this stuff!! Another great video!
+Che Kelley I agree, thanks for watching!
Thank you very much for the help.
apologize,
we have some problems with lnternet and youtube not availble here, in Iran,
oh, governers filteration
we have some words to thanksgiving a teacher,
people balive one of holy man has said that;
I will serve all my life who that teach me just one word!!
I learn more from you videos
thank you
Thank you very much!
Excellent transmission
Thanks for your feedback
Just think of the mad geniuses that designed this thing in the first place. Give them a Nobel
Agreed!
Of course it’s the Germans
I have learned so much about automatic transmissions through watching your videos, so thank you very much for posting everything up and being as detailed as you have been.
I was wondering if you knew anything about the VW 01M transmissions? I have had experience of them (not a great one, I'll tell you!) and it took a while for the issues to be identified and sorted out. That car has gone, but I still never understood why the transmission was so poor (it seems many others have had hard-to-diagnose problems with them, surrounding hard shifts after everything has warmed up - say 20 minutes of driving)
Hi, thank you for your kind words. I have not had any experience with the VW 01M transmission. Hopefully, I will get some in the future, but we do not do much VW works at our school. Best wishes!
@@WeberAuto سلام
Thank you. For the class.
Have you thought about Cutting windows into those 'shells' such that you could still point and spin or hold clutches/sun gears so you could show the power flow for each gear ? Windows would allow you to touch/hold parts and be able to see them for illustration purposes.
Thanks for presentation !!
Thanks for the suggestion
Satisfying to see the way he attach the gear set
It's easier to view power flow through the 8HP70/90 if you have a model loaded to Catia or SolidWorks. You have to be within ZF's supplier network to get that though.
Master teacher! Thank you.
Thank you!
the valve body does have serviceable parts and those are the solenoids for each gear. just pop them out and replace with the new ones.
The best and most efficient plus cheapest and simplest powertrain for both ICEs and EVs is the Positive Drive Infinitely Variable Transmission, PDIVT.
The power transmission starts from the center of input shaft and shifts ouwards as the vehicle has gaining more speed.
It offers what CVT can do but in positive drive. And starting from center of input shaft. This is the best solution for heavy vehicles such as trucks, buses as well as hypercars, sedans and motorcycles.
The world needs innovation and breakthrough in technologies. Make a change if we care about emissions and global warming. Because the PDIVT powertrain will greatly improve the efficiency of transmitting power from engines to wheels. And this will save fuel and energy causing less emissions issues.
nice explanation, it seem those sleeves that transfer power won't hold up if they can be deformed with a screwdriver, but I guess the engineers know what they are doing, I have a v6 ram with zf8hp45, sometimes get a hard 1-2 shift but otherwise very smooth transmission,
So I have a 22 Wrangler with the ZF 8Sp. Several Jeep owners have been experience a whirring sound (sounds like a bearing) at low gears (1st and 2nd), nothing seem to be out of wack. Vehicle is driving fine. Is that a normal characteristic of the ZF transmission?
Спасибо мужик, теперь мне понятен принцип работы АКПП.
Коробка напоминает матрёшку
nice explanation.
Thank you
I’ve never drove a dodge product with the 8HP but the BMW’s 8HP shifts like a sequential transmission. Mine will bang gears when I’m in sport mode.
What an amazing tutor!
Then a few years later they refine this into the second Generation, another few pounds lighter, smaller and stronger. My car has the ZF 6HP, my mom's car has the same one as your described.
Thanks for watching
You got my respect sir!
Thank you!
They need a better transmission fluid for these transmissions, on the Amsoil video by Eben he shows the cold pour test and Mopar ZF 8&9 transmission fluid is like and ice cube below 32°f. It seems like that some one would burn transmission up trying to drive in the colder months.
Thank you for watching
I disagree with the notion that the valve body cannot be easily serviced, but the rest is spot on. Excellent content clearly explained. Are there additional shims and/or thrust bearings used here and there, or just the one thrust bearing?
we also have this transmission in a ram 1500 4wd/hemi. it really is an amazing piece of engineering, and its great to see the internals even though i dont understand most of it!!
driving with it is seamless, ty[ically 3 shifts before you cross an intersection from a red light and then on the otherhand it also preforms flawlessy towing our 8000 lb travel trailer up the steepest and longest of hills. if you know, could you explain what happens in "tow/haul" mode and when we should be using the manual shift buttons
Hi I’m working on a 8hp65 there is fluid coming out of the side of the trans fluid towards the back. I took the transfercase filler plug out and a bunch of fluid came out. Is there a seal that keeps the trans and transfercase separated?
Best Gearbox ever built!
wow how those thin cans hold that much torque... great vid...
Thanks for watching
I have a 2018 B9 Audi S4 with the 8HP65. How important do you think it is that we use “approved ATF fluid?” Their is some talk of liqui Moly 1800 being suitable for this transmission, I honestly don’t believe that. I highly recommend ZF LifeGuard 8 which is designed for this complex transmission. Do you think people would be causing premature wear/damage using any fluid other than ZF etc.? Thanks! Amazing video! This transmission is INSANE, I am tuned, and it’s just incredible this transmission is able to increase shift speed and response with tuning just amazing ZF does have the most advanced Torque Converter Transmission in the world.
No. There is a specification of fluid for this transmission if the fluid meets that spec you can use any brand.
Ive got a 2017 durango sxt awd with the 845re and its a piece. Getting its 3rd valve body installed now. I doubt that the problem though. P0733 code rough 3-4 shift that jerks your head.
thank you for all this information
but who is more reliable nag1 5 speed or this zf 8 speeds ?
who is gonna last longer with no problems ?
The NAG1 has been here since 2005 in Chryslers, even longer in Mercedes; it has been very reliable. The ZF 8HP has been here since 2013 with very few issues. time will tell.
I think you'll find that the 8HP has been around since 2008, first in BMWs and then elsewhere.
nice video! sucks the way they are creating these now days where you cannot get replacement parts for the value bodies and the pan is the fliter... im sure a full assembly is not cheap and that filter pan is more than just a plain old tran fliter plus no dipstick makes it harder for an owner to service their own vehicle.. its great for builders and companies . ..
+Sean Metz Thanks for watching and for your feedback.
Great info. Thanks for sharing.
+RCFiddyOne Thank you!