Diff rebuild - how to set backlash Ep. 3
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- Опубликовано: 13 сен 2024
- The third of the 4 adjustment processes required to set up a differential or Final Drive unit.
In this video Tool Girl Sam gives me a hand setting the 'Backlash' between the crown wheel and pinion gears - a critical clearance, too little and there will be poor lubrication, premature wear & likely to whine at highway speeds. Too much clearance and the drive train will be clunky and you run the risk of breaking teeth off the gear set too...
So, in this video we run through the backlash adjustment and how to take the readings using a DTI gauge.
Andy Mechanic
The absolute BEST video on this topic I've seen! And with the absolute bestest assistant mechanic! I love the lip piercings and studs as much as the demonstration of mechanical engineering! Many Thanks !
The Best video help I ever seen I was watching your 4 clips about diff and assembled mine first time in my life and is perfect. Thank you very much
Damn I just stumbled on this channel and I love how you let non car people do it, cause if they can do it then I can do it too!
and just finished doing it! Thanks heaps Andy
Thanks Andy, good demo of setting the backlash. I taught the maths for mechanics, such as ratios and engine capacity and estimated HP and torque, also vehicle aligment. Students are stunned that they still have to do maths. I was away when they did this. you are a natural teacher. I also did the maths support for other trades at TAFE and have seen good teachers.
+Peter Andrews Thanks Peter. I really enjoyed the 5 years I spent teaching. Thanks for your comment. Cheers Andy
Nice video Andy. Resetting bearing preload is often overlooked. In fact, back in the '80's doing my first dif, w/ a friend and his dad, we did not rest the preload. Guess what we did about 3 weeks later! ;) Also, I have gotta say, Sam is very cute. I love her concentration, looks like she is absorbing as much as she can! It is hard when everything is so new, hang in there!
Really good content , great detail! hard to come by these kind of breakdowns
Never heard of using a piece of paper between crown and pinion until it almost cuts as you turn it...? Perfect adjustment Every time..!
but does that set the bearing loading thing?
Hi.
Happy new year,
Thank you
Australia
Karl
Very interesting Andy, reminds me of the times When I do the timing on the injection pump on the old v w diesel , just get it right , then tighten up the pump , rotate the motor and it's out. 4. Degrees. Start again , but get it in the end.
I was worried about doing my own diff rebuild but these vids have given me a little bit of confidence and understanding. Haven't checked out the other vids yet but this one is super informative and very easy to understand. Thank you Andy, I appreciate ya! Keep up the good work. SUB'd!!!!!!!!!
👍
That is a very good video I’ve watched a lot of them on backlashes but that’s the best one I’ve seen very good
Cheers :-)
I really appreciate this series
Cheers. Thanks for the feedback. Andy
m8 very great video thx u
Your helper is smoking hott. I cant even focus on the point of the video
Thanks was very helpful and informative being as I had not a clue on what I was doing ! Thanks again! 32:14
👌
2:30 🤔🤔good point, differential setting is uhffffff.
My toyota 8" JZX100 diff just shat itself because of excessive backlash I had. 265 semi-slicks and grippy prepped pavement. First to second shift and it didn't spin the tires like it would normally do through 2nd gear all the way. Instead I had massive wheel hop and second later huge explosion causing half of the crown wheel and pinion teeth flying inside the diff housing. :D
Learned my lesson now, never drive a high horsepower car or any kinda vehicle with noisy/bad diff. I knew it had all kinda issues just by turning the pinion flange. Preload was off or the bearings were worn out, in/out and side play well over 2mm and backlash clunk noise. I thought it could survive few months more before winter time to rebuild it. :(
Im currently shocked right now , i worked on my friends deferential replacing the bearings and i tried to put them back in the way i got them out and it worked fine no noise and dont seem to ave any back lash
Oh....no backlash at all? It needs a bit to allow for thermal expansion. It'll force the oil out from between the teeth - this will then generate heat and excessive pressure on the teeth - often this breaks through the hardened surface on the teeth or possibly even snap or chip teeth. It also loads up the pinion inner bearing too so that may fail first.
However, if it's working then maybe there was just a little bit of backlash that you maybe didn't notice? I'd leave it alone and have a cider :-)
Cheers Andy
@@AndyMechanic Thank you so much for your reply and useful info, yes their might be a bit of back lash but when i drive it i dont feel it but i dont have the tool to check the amount of slack between both gears. but so far so good and i am having that cider writing you this comment. if i do get any problems i will do it the right way next. their is something but its been their for a while , i dont seem to know why i dont have enough power its like the car can barely carry it self.
best regards, and many thanks
Nice video, but she was my focus a bit confused, who is she to you?
I'm a connoisseur of rear ends...and I must say that Sam has a great rear end!😮
Isn't it easier to use an inch lbs dial torque wrench to set pinoin and/or carrier preload?
I also like your assistant "Sam"
Keep up the good work. Enjoyed videos.ill watch more.
Mike from cali.
Question. Before setting the backlash, what is the initial setting of the bearing?
Nice, technically a little to slow for me, but this way u can see more detail you otherwise me by forgetting to tell.
And by the way Sam is such a nice tool girl, I like that she gets more into this, keep up the work!
FIRST! XD
+Martin L Thanks Martin, I agree, Sam is awesome. Thanks for your feedback. Cheers Andy
great video. I do have to wonder though, on the total bearing preload, using the flange hole instead of the pinion nut would give a mechanical advantage. if the hole is 2 inches from the nut, the reading in inch pounds would be half . Im not good at converting mm and nm from inch pounds, but same thing, different units.
Agree completely, it all depends on the method of measurement. Some manufacturers measure from the pinion nut, others from one of the prop shaft holes - this is exactly why you need the required service manual & not just the specs.
Cheers Andy
What’s the gloves for 😅
Land Rover Diffs do have a flat metal plate to fit a Dti base but they don't show this method for checking the backlash.
Toque the mains on carriers and the pattern on the ring gear and pinion
Why are you not loosening the bearing caps when adjusting pre-load and tighten before checking pinion rotation
Is this how all or almost all diffs are adjustable?
I can hear some bad backlash on my puck up 😔
The theory & method is the same for the vast majority of diffs, however there are a few different designs of adjustment - but once you understand the process & aim it's easy to work out.
Cheers Andy
Thanks Andy, I have a question on the method applied to adjust backlash. By tightening both ends of the adjustment wheel, doesn't this decrease the backlash? I can see by the reading that it hasn't but I was just curious why that is the case? I would have thought to increase the preload you would just tighten the side that doesn't have the crown wheel?
the backlash will be adjusted if u move the crown from left to right. that means opening up one of the locks and closing the other, which they did in the first part of the vid... that will shift the gear left or right, giving u tighter or loser backlash.
but u understand that.
now to set the preload, if u want to keep the backlash adjustment the same, they would have to not move the ring gear left or right. so, what ever adjustment they make to one of the locks, they would have to do the same thing to the other side. eg. if they need to load more, and they need to turn the lock in by half a turn, they woudl do same thing with the other lock so the net movement of the ring gear will (should) be 0.
personally, i would check back the backlash after the preload, just to confirm there wasnt any small discrepancies, cause i aint no precision guy.
hi what could happen if i set my gear ring at 0 back lash?
It will destroy itself due to thermal expansion as it warms up.
Is this any different for a limited slip differential. Im looking at rebuilding the diff and installing a 3.73:1 Eaton positraction diff in my c20.
Its the same for sure..
I've never seen those adjusters before what locks them into place. Looking forward to to the next video. If the pinion depth is wrong you will have to start
again?
+Andrew Thompson there are steel tabs that Bolt into place locking the wheels. Yes, you have to start all over again if pinion depth is wrong.
Pleased you liked the videos & thanks for the feedback. Cheers Andy
What does Sam drive? Don't think it sounds as cool as Harley's MK2 Escort, though..
So you saying that's the best you can do on the tracking pattern ?
Piper Perri?
Nope.....Sam is way better looking & far more respectful.
@@AndyMechanicagreed. Explained very nicely, installing a spool carrier in my usdm GTO m80 pretty soon.