My theory behind the converter failure is that it’s a multitude of things. 14-16 trucks have a 195° thermostat in the transmission cooler lines which is too hot for transmission fluid. 17+ has 160° thermostat in the cooler lines as an update to try and prevent converter failure. They also allow a 40rpm slip with the converter clutch while it’s “locked up” for the AFM system. Between high transmission fluid temps, the 40rpm slip and lockup engaging in 2nd gear is what wipes the converters out in these. Deleting the transmission thermostat along with replacing the fluid, converter and o-ring seems to do wonders for these trucks and it seems to mostly affect 14+ and not many below. Edit: the converter also has been superseded by a new part # from GM
Hey man - I was a test engineer at a torque converter tier 1 supplier in Ohio. From you video I wanted to tell you a few things. First off, awesome video! I've wanted to see what the tc's lock up clutch did. Second - the piston that applies pressure to the lock up clutch has leaf springs between the inner top shell to the outer shell that wraps around the bottom. They separate from each other under a pressure differential governed by the transmission controller. 3.) aluminum casting seems normal imo - especially for a non prototype. Possibly some cavitation happening. Obviously not a great casting. The stator also has a clutch commonly known as the one way clutch that does lock up during acceleration and what helps generate torque based on the redirection of the fluid force vectors of the blades. This is usually what you test - the one way clutch on stator. It locks up in only one direction and free wheels in the other. Again - all governed by fluid force vectors. 4.) I think this TC is what's called a 2 pass TC. It's for two main fluid passage ways. The first is as you said that comes into the many area between the impeller blades, stator, and turbine. This is known as the torus. The other passage way is the opposite direction and locks up the converter clutch due to that pressure differential. The TC will not generate additional torque anymore and the torque ratio is 1:1 at this point in terms of input (impeller/ pump) to output ( turbine). There is also 3,4 and 5 passage way converters with more control on the converter lock up clutch. 5.) I believe most converters lock up clutches do continue to slip all the time based on Manufacture tuning. But it's within very low % differential between input speed and output speed of the respective turbine parts.
Great video. I have a 2015 Silverado with 105k on it that has done a ton of heavy towing and will continue to do so. I flushed and replaced the fluid and filter at 75k, but I'm considering replacing the converter as a PM measure as it is the primary cause of these transmissions failing.
Nicely explained. I agree with you, even though there are now a lot of videos on this topic, none illustrate the fine details well. Even getting it all apart leads to questions, the design is so elegant. I'm surprised there is a core charge for these things, since to get one apart you'd have to cut into it with a grinder and then re-balance it after replacing seals, clutch material, etc. I wonder if they simply test them out on the bench, somehow replace seals without cutting welds, then resell them as rebuilt.
Thank you Sir. Like you, I found many videos about the issue but none that showed it. Great video. I will be replacing mine soon, likely with a Circle D forged. I have no mods but will be towing a camper.
FYI if the converter shuddered the front pump of the trans will be trashed you will need a rebuild do not just change the converter you will have low fluid pressure and trash a brand new converter do your homeowork it’s the front pumps not being strong enough to keep constant pressure ie the bell housing. Low pressure causes the converter to lock and unlock causing heat witch is taking out the converters.
What did the shudder feel like on yours? I’ve got a 2014 that has a shudder that’s very mild, feels like an imbalanced tire and shows up at highway speeds. I’m hoping maybe the dealer could just swap the converter before it kills the whole transmission, if that’s what is causing the shudder
How is the heavy duty 6l90 torque converter holding up? I’m planning to replace my 6l80 torque converter soon. Where would you recommend for a billet tc . Or should I upgrade to the 6l90 tc. Thanks
Did you have and TCM codes ? What are the exact symptoms of this issue ? I don’t really know how to identify the shudder but I can feel something is off with shifting and now there is a slight noise
ok so my 15 started to shutter, stopped driving it until i did fluid, filter and thermostat change. even added lube guard. still doing it. idk if it's just the torque converter or if there are more messed up clutches? if I have it in tow mode it does better. just fishing here thanks.
Great video thanks ,👍👍👍 Not sure what to do with mine. Seems to shift good.(sometimes down shifts funny), but im thinking my converter is going bad. Shudder, especially when getting up to speed, but then when im driving at speed mine gets this hard crazy vibration for a split second, then goes away. More when im accelerating than anything. Then im torn on what to do about the trans. If I change the converter, should you go ahead and revuild the trans??
Reman transmission. The parts were 1/2 the cost of a reman. And no one would touch it locally since I removed it and diagnosed it. On the 6l90 the front pump will fail and the bellhousing is part of the pump housing. So all those parts just to have a 200k mile trans fix, made no sense to me. Reman has at least some warranty.
I should add. I thought it was my converter is why I pulled the trans. Then once I got it out and started looking and doing research I found the transmission was full of aluminum shavings.
Wow - so the lockup clutch material is just 'painted' on the disc in the OEM torque-converter ?? I wonder if there is even any oil-flow thru this lockup-clutch area when it's supposed to be locked up (overheats/cooks oil?)?
Just replaced the TQ converter in my 2015 with 201,000 miles it was making a sound almost like hitting rumble strips and RPM fluctuation. There was quite a bit of material on the magnet in the pan. New heavy duty TQ converter and filter with fluid flush and it drives like new.
If you don’t mind me asking what made you decide to only do the torq converter? I have had my truck in to dealership and 2 other trans shops. They all said it needs a rebuilt trans. My car runs pretty well. There is a small hiccup on the downshift between 2 and 1 and tiny little slip sometimes going up 3 to 4. My trans has 203000 miles on it. I have a little metal in the pan. Thanks in advance for your feedback!
Your transmission probably got shredded by the debris. He caught his before it became a problem. When they fail, they burn away the clutch material and go metal on metal. That tears up the valves and pump and the clutch packs. I'm currently in the same position... mines failing and slipping, I'm hoping the transmission isn't too damaged. Hope a new torque converter and rebuilt pump, a flush and a filter will be all it is. I plan to keep the truck long term. So I'm planning to throw some good parts at it to make sure I can resell the transmission once the truck rust away to nothing. Lol. The motor will get the same treatment if it ever has to come out.
Fluid still passed underneath the clutch while lock up is applied. Gm made tcc slip intentionally on these units. The Converter fails because the front cover overheats and warps. When tcc slips while the converter is in lock up it destroys the carbon woven lining. (the lining is only 00.20 tall). The real reason these units fail is do to the pressure control valve in the pump wears out and the transmission begins to over heat. Then it blows out the converter
They certainly dropped the ball. That's for sure. My transmission never got "hot" but my converter is definitely failing. I'm not sure what in the hell to do at this point
You said you started to have shudder around 80k. How often did you service it ? Edit: 😂..after looking at comments it seems you don't reply to questions..
A thief is a more honorable occupation than being a GM powertrain engineer. My impeccably maintained 2016 2500HD is on its third transmission at just 65k miles. This time an independent shop rebuilt it because the OEM parts are shit. It has a billet torque converter, Sonnax internals, a Tru Cool 40k transmission cooler and a tune. Hopefully this one lasts. I’ll walk before I spend another dime on a GM product.
All that work and you put Fram ATF in it? I think Fram oil filters get a bad rap, which I think they are fine as long as you change them when you’re supposed to. But to not use the synthetic Mobile One or Amsoil ATL is a mistake. Good luck with it!
I'd throw Fram fluid in it for the original fill after rebuild, then flush it and new filter after its been run to clean and dirt/manufacturer debris and assembly lube. But most fluids are basically the same a budget synthetic is still a good fluid.
My theory behind the converter failure is that it’s a multitude of things. 14-16 trucks have a 195° thermostat in the transmission cooler lines which is too hot for transmission fluid. 17+ has 160° thermostat in the cooler lines as an update to try and prevent converter failure. They also allow a 40rpm slip with the converter clutch while it’s “locked up” for the AFM system. Between high transmission fluid temps, the 40rpm slip and lockup engaging in 2nd gear is what wipes the converters out in these. Deleting the transmission thermostat along with replacing the fluid, converter and o-ring seems to do wonders for these trucks and it seems to mostly affect 14+ and not many below.
Edit: the converter also has been superseded by a new part # from GM
Thanks, I think you are the only one on yt that does a breakdown on a 6l80 torque converter
Hey man - I was a test engineer at a torque converter tier 1 supplier in Ohio. From you video I wanted to tell you a few things.
First off, awesome video! I've wanted to see what the tc's lock up clutch did.
Second - the piston that applies pressure to the lock up clutch has leaf springs between the inner top shell to the outer shell that wraps around the bottom. They separate from each other under a pressure differential governed by the transmission controller.
3.) aluminum casting seems normal imo - especially for a non prototype. Possibly some cavitation happening. Obviously not a great casting. The stator also has a clutch commonly known as the one way clutch that does lock up during acceleration and what helps generate torque based on the redirection of the fluid force vectors of the blades. This is usually what you test - the one way clutch on stator. It locks up in only one direction and free wheels in the other. Again - all governed by fluid force vectors.
4.) I think this TC is what's called a 2 pass TC. It's for two main fluid passage ways. The first is as you said that comes into the many area between the impeller blades, stator, and turbine. This is known as the torus. The other passage way is the opposite direction and locks up the converter clutch due to that pressure differential. The TC will not generate additional torque anymore and the torque ratio is 1:1 at this point in terms of input (impeller/ pump) to output ( turbine). There is also 3,4 and 5 passage way converters with more control on the converter lock up clutch.
5.) I believe most converters lock up clutches do continue to slip all the time based on Manufacture tuning. But it's within very low % differential between input speed and output speed of the respective turbine parts.
Great video. I have a 2015 Silverado with 105k on it that has done a ton of heavy towing and will continue to do so. I flushed and replaced the fluid and filter at 75k, but I'm considering replacing the converter as a PM measure as it is the primary cause of these transmissions failing.
Well done. Very informative. Saw and learned what I needed. Thank you.
How long did this new torque converter last. Was it a permanent fix or did you have to do the trans?
Nicely explained. I agree with you, even though there are now a lot of videos on this topic, none illustrate the fine details well. Even getting it all apart leads to questions, the design is so elegant. I'm surprised there is a core charge for these things, since to get one apart you'd have to cut into it with a grinder and then re-balance it after replacing seals, clutch material, etc. I wonder if they simply test them out on the bench, somehow replace seals without cutting welds, then resell them as rebuilt.
Thanks for the video man the best I found yet
Thank you Sir. Like you, I found many videos about the issue but none that showed it. Great video. I will be replacing mine soon, likely with a Circle D forged. I have no mods but will be towing a camper.
FYI if the converter shuddered the front pump of the trans will be trashed you will need a rebuild do not just change the converter you will have low fluid pressure and trash a brand new converter do your homeowork it’s the front pumps not being strong enough to keep constant pressure ie the bell housing. Low pressure causes the converter to lock and unlock causing heat witch is taking out the converters.
Can you explain more
So I might as well let it blow up and just rebuild it better.
What did the shudder feel like on yours? I’ve got a 2014 that has a shudder that’s very mild, feels like an imbalanced tire and shows up at highway speeds. I’m hoping maybe the dealer could just swap the converter before it kills the whole transmission, if that’s what is causing the shudder
yes thats what I did ,dealer didnt want to do it without the trans... ended up just doing the tourque conv. worked so far for 30k
GM OEM converters made in CHINA look it up my converter went at 113,00 miles replacing with DACCO PARTS
It sounds similar to if you had a standard trans, slowed down, well under your torque and tried to accelerate. It's almost a growling.
mine is doing it at 80k
How is the heavy duty 6l90 torque converter holding up? I’m planning to replace my 6l80 torque converter soon. Where would you recommend for a billet tc . Or should I upgrade to the 6l90 tc. Thanks
Did you have and TCM codes ? What are the exact symptoms of this issue ? I don’t really know how to identify the shudder but I can feel something is off with shifting and now there is a slight noise
ok so my 15 started to shutter, stopped driving it until i did fluid, filter and thermostat change. even added lube guard. still doing it. idk if it's just the torque converter or if there are more messed up clutches? if I have it in tow mode it does better. just fishing here thanks.
Great video thanks ,👍👍👍
Not sure what to do with mine. Seems to shift good.(sometimes down shifts funny), but im thinking my converter is going bad. Shudder, especially when getting up to speed, but then when im driving at speed mine gets this hard crazy vibration for a split second, then goes away. More when im accelerating than anything. Then im torn on what to do about the trans. If I change the converter, should you go ahead and revuild the trans??
My 6l90 was full of aluminum and it was the pump grinding the pump housing/bell housing
How did you remedy this?
Reman transmission. The parts were 1/2 the cost of a reman. And no one would touch it locally since I removed it and diagnosed it. On the 6l90 the front pump will fail and the bellhousing is part of the pump housing. So all those parts just to have a 200k mile trans fix, made no sense to me. Reman has at least some warranty.
I should add. I thought it was my converter is why I pulled the trans. Then once I got it out and started looking and doing research I found the transmission was full of aluminum shavings.
Wow - so the lockup clutch material is just 'painted' on the disc in the OEM torque-converter ??
I wonder if there is even any oil-flow thru this lockup-clutch area when it's supposed to be locked up (overheats/cooks oil?)?
Just replaced the TQ converter in my 2015 with 201,000 miles it was making a sound almost like hitting rumble strips and RPM fluctuation. There was quite a bit of material on the magnet in the pan. New heavy duty TQ converter and filter with fluid flush and it drives like new.
If you don’t mind me asking what made you decide to only do the torq converter? I have had my truck in to dealership and 2 other trans shops. They all said it needs a rebuilt trans. My car runs pretty well. There is a small hiccup on the downshift between 2 and 1 and tiny little slip sometimes going up 3 to 4. My trans has 203000 miles on it. I have a little metal in the pan. Thanks in advance for your feedback!
Your transmission probably got shredded by the debris. He caught his before it became a problem. When they fail, they burn away the clutch material and go metal on metal. That tears up the valves and pump and the clutch packs. I'm currently in the same position... mines failing and slipping, I'm hoping the transmission isn't too damaged. Hope a new torque converter and rebuilt pump, a flush and a filter will be all it is. I plan to keep the truck long term. So I'm planning to throw some good parts at it to make sure I can resell the transmission once the truck rust away to nothing. Lol. The motor will get the same treatment if it ever has to come out.
Get HP Tuners and tune the trans. Well worth it!
Hey give us an update, no shudder a year later? Ty
I have a shudders on 45mph and above on my 6L80 2011 camaro ss. I cut the TC and found it in perfect condition. Nobody can stop this shudders ((
pump housing/ bell housing?
Fluid still passed underneath the clutch while lock up is applied. Gm made tcc slip intentionally on these units. The Converter fails because the front cover overheats and warps. When tcc slips while the converter is in lock up it destroys the carbon woven lining. (the lining is only 00.20 tall). The real reason these units fail is do to the pressure control valve in the pump wears out and the transmission begins to over heat. Then it blows out the converter
They certainly dropped the ball. That's for sure. My transmission never got "hot" but my converter is definitely failing. I'm not sure what in the hell to do at this point
Did u have n engine light
You said you started to have shudder around 80k. How often did you service it ?
Edit: 😂..after looking at comments it seems you don't reply to questions..
Because he doesn't really know wtf he's talking about he's yakking on and on. It sounds good but thats why he doesn't respond to anyone!!
THANK YOU!
A thief is a more honorable occupation than being a GM powertrain engineer. My impeccably maintained 2016 2500HD is on its third transmission at just 65k miles. This time an independent shop rebuilt it because the OEM parts are shit. It has a billet torque converter, Sonnax internals, a Tru Cool 40k transmission cooler and a tune. Hopefully this one lasts. I’ll walk before I spend another dime on a GM product.
Check out my TCC/Lock-up explained video!
You have to use sonnex parts and get a billet converter and done
I hope you rebuilt the trans when you put that new converter in. You can’t just throw a new converter at these when the my fail.
mine is doing the shuttering at 70k. so pissed.
All that work and you put Fram ATF in it? I think Fram oil filters get a bad rap, which I think they are fine as long as you change them when you’re supposed to. But to not use the synthetic Mobile One or Amsoil ATL is a mistake. Good luck with it!
I'd throw Fram fluid in it for the original fill after rebuild, then flush it and new filter after its been run to clean and dirt/manufacturer debris and assembly lube. But most fluids are basically the same a budget synthetic is still a good fluid.
Unfortunately this converter shows how poorly made
GREAT VIDEO,,,,BUT ,,,THE VIDEOING,,,,,,,, BUT THE INFO I EVEN GOT!!!!!!!!! SO NO EXCUSES FOR ANYBODY GETTING IT NOW
Remember, aluminium will not stick to the magnet in the pan.