Rear diff... Help!!!!
Safety Car
Joined: Sep 2007
Posts: 4,454
Likes: 328
From: Indy Indiana
buying the unit posted does not guarantee that it is complete not needing rebuild and that it may or may not have been set up correctly. only if the pinion nut has not been touched would I even think about risking just bolting the rear end in. Then at best it is a 50-50 risk that you are back to square one.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
buying the unit posted does not guarantee that it is complete not needing rebuild and that it may or may not have been set up correctly. only if the pinion nut has not been touched would I even think about risking just bolting the rear end in. Then at best it is a 50-50 risk that you are back to square one.
Screen name is Redvetteracer. Has the rear end been in his red vette racing? Hard to say but these units are all over 30 years old so even an unmolested unit could really need a rebuild. Looking behind the rear cover and finding it "clean" does not necessarily meen it doesn't need a rebuild.
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
This is not correct. Check this exploded view. The crush sleeve is between the bearing and the flange. It is crushed too far if you cranked it down with an impact. It has to be replaced. You might get your preload set right but the nut holding the pinion flange on will back off when driving.
http://www.duntovmotors.com/63-79Dif...plodedView.htm
http://www.duntovmotors.com/63-79Dif...plodedView.htm
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
I know what the F*&^%g thing looks like in there. I have rebuilt lots of them. And the shim that sets the pinion is directly under the pinion gear. Once the play is removed, further tightening of the nut does not significantly change the pinion setting. Certainly not enough to make it growl on coast and only on coast. I am not arguing that he shouldn't have done what he did, but his symptom would indicate that he has not tighten it enough. If he has destroyed the bearing it would be making noises all of the time in both acceleration and coast.
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
No need to get angry. Question for you is what did the crush sleeve do when he layed on it with the impact? It collapsed sucking the pinion toward the front of the differential. The crush sleeve needs to be replaced and probably at least the pinion bearing and seal. If it comes apart this far the backlash needs to be resetup and it is quite possible there is other damage as well and everything should be inspected. This is how I look at it. You may have a different opinion. You are entitled to your opinion but, I am also entitled to mine and put the illistration up so the OP could see the consequences of tightening the nut way too tight.
Thread Starter
Instructor
Joined: Mar 2010
Posts: 205
Likes: 2
From: Sneads Ferry NC
Well you sound like you know what you are talking about wombvette, I am going to try to tighten it more by hand and see if that fixes or at least lessens the problem. If not then plan B...
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
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Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
If the unit has minimal end yoke play, comes complete and is a drop in unit. Might check these guys: http://corvettepartsonline.net/
Don't know the quality of there build or if sideyokes and rear cover are included. One picture shows side yokes, one doesn't but a 3 year warrantee sounds good. Might be a good time to upgrade to a different gear ratio. If you have a 3.08 a 3.55 really makes a difference in performance but it will RPM a little more cruising.
Many, many horror stories.
http://forums.corvetteforum.com/c1-a...nline-com.html
http://forums.corvetteforum.com/c3-g...ts-online.html
http://forums.corvetteforum.com/c3-g...am-artist.html
Last edited by noonie; Mar 17, 2010 at 11:00 PM.
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Don't just arbitrarily tighten it. Check it for end play first. Also, I would ask what the reason for changing the yoke was?
Racer
Joined: Dec 2008
Posts: 255
Likes: 4
Cheap rebuild of diff, done right
My machine shop rebuilt my diff which had spun a side bearing. He made a bushing and replaced all bearings and seals. I put it back in and it is perfect with no leaks. He will completely rebuild a rear for no more than $300 if it doesnt require any special repair (like mine did). If you are interested PM me for info.
Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
When you pull the driveshaft you will be able to tell if you under tightened the pinion nut.
The yoke will move slightly in and out as you turn it. You will be able to tell its loose.
I resealed my diff a while back and when I first drove the car I had the same problem you do. Under decel it would howl.
This is despite the fact that I did the work out of the car, it wasnt my first time at this, and I did check turning torque.
Apparently something didnt seat just right when I put it back together and it had play in the pinion. I retightened it and it has been fine since.
Good luck with yours.
The yoke will move slightly in and out as you turn it. You will be able to tell its loose.
I resealed my diff a while back and when I first drove the car I had the same problem you do. Under decel it would howl.
This is despite the fact that I did the work out of the car, it wasnt my first time at this, and I did check turning torque.
Apparently something didnt seat just right when I put it back together and it had play in the pinion. I retightened it and it has been fine since.
Good luck with yours.
Thread Starter
Instructor
Joined: Mar 2010
Posts: 205
Likes: 2
From: Sneads Ferry NC
I replaced it because the the bolts that hold the drive shaft to the yoke broke and it damaged the yoke and drive shaft in the process. I am going to take a look at it this weekend and see if there is a quick fix or easy fix.
Cruising
Joined: Mar 2010
Posts: 14
Likes: 0
Stay away.
Many, many horror stories.
http://forums.corvetteforum.com/c1-a...nline-com.html
http://forums.corvetteforum.com/c3-g...ts-online.html
http://forums.corvetteforum.com/c3-g...am-artist.html
Many, many horror stories.
http://forums.corvetteforum.com/c1-a...nline-com.html
http://forums.corvetteforum.com/c3-g...ts-online.html
http://forums.corvetteforum.com/c3-g...am-artist.html
Le Mans Master
Joined: Jan 2006
Posts: 6,504
Likes: 139
From: Butler Pa
FWIW, I replaced the pinion seal in my diff about 4 years ago. I didn't replace the yoke but just tightened the nut with an impact. The turning torque seemed the same as before I took it apart. It's been fine ever since. I probably have 2500-3000 miles on it since.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Thread Starter
Instructor
Joined: Mar 2010
Posts: 205
Likes: 2
From: Sneads Ferry NC
Well i pulled my vette into the shop and went over my work, I took the yoke back off turned it 180 and put it back on, this time using the right tools, everything seems to be working great, no leaks, no sounds, just a smooth ride
Racer
Joined: Nov 2006
Posts: 264
Likes: 0
From: McLouth Kansas
Don't drive that car another foot,,,you could cost your self some big bucks,,your pinion gear is striking your ring gear housing when the torque is dropped of when you let off the gas.
ck your PM that I sent you,,,in a sense I did the same thing you did but in a different manner. And I had the same results as you,,but don't drive that car.
ck your PM that I sent you,,,in a sense I did the same thing you did but in a different manner. And I had the same results as you,,but don't drive that car.
Racer
Joined: Nov 2006
Posts: 264
Likes: 0
From: McLouth Kansas
I see you have it sounding ok,,,,but your pinion gear may be too deep or not deep enuf in to your ring gear,,,,you may have problems later,,unless you are one lucky son of a gun and accidentally got it right.