Rear diff... Help!!!!
Thread Starter
Instructor
Joined: Mar 2010
Posts: 205
Likes: 2
From: Sneads Ferry NC
Rear diff... Help!!!!
I put in a new drive shaft and pinion yoke, I lost some oil out of my diff when I took off the yoke and topped the diff off with regular ole 80W90 now when I let off the gas I get a HORRIBLE sound and vibration from the rear end. What can I do to fix this problem and what have I done to kill me rear diff? Please help my heart is in my stomach right now. 
Racer
Joined: Jul 2008
Posts: 446
Likes: 1
From: Cary NC
This probably won't fix the problem but put some gear oil in along with GM Positraction Additive. Here's a link: http://www.zip-corvette.com/ProductDetails/ProductDetails.aspx?pid={2ca5ba6a-fcb8-4eea-bd0c-af2eb6fbaf77}&gid={fec52836-d7e0-424a-881c-316a6ec43a5b}&GroupName=Gear+Lubricant+% 26+Additive&pname=GM+Positraction+Additi ve&Referer=&Alias=&ptct=SGR-SR&CTitle=&
and
http://www.zip-corvette.com/ProductDetails/ProductDetails.aspx?pid={cc10777f-0bff-4cdc-92d5-5a7a946bfb00}&gid={fec52836-d7e0-424a-881c-316a6ec43a5b}&GroupName=Gear+Lubricant+% 26+Additive&pname=GM+Gear+Lubricant&Refe rer=&Alias=&ptct=SGR-SR&CTitle=&
and
http://www.zip-corvette.com/ProductDetails/ProductDetails.aspx?pid={cc10777f-0bff-4cdc-92d5-5a7a946bfb00}&gid={fec52836-d7e0-424a-881c-316a6ec43a5b}&GroupName=Gear+Lubricant+% 26+Additive&pname=GM+Gear+Lubricant&Refe rer=&Alias=&ptct=SGR-SR&CTitle=&
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
If the vibes are only there on decel then then the issue is with the pinion mesh. You took the yoke off at the diff side? You normally can't do that without screwing up the pinion backlash....time for a rebuild I am afraid....
Hope I am wrong.
Hope I am wrong.
Thread Starter
Instructor
Joined: Mar 2010
Posts: 205
Likes: 2
From: Sneads Ferry NC
Yeah I took the yoke off just by loosening up that one nut that holds it on and replaced it, I did notice a good bit of play in the pinion but didn't think it would make such an amazingly horrible sound. I also found if I keep just the ever so slightest bit of power on the drive train then I don't get that horrible vibration/sound.
Instructor
Joined: Mar 2010
Posts: 228
Likes: 0
From: Evansville WI
To do it properly, you have to take the differential it's self out of the housing, put in a new crush sleeve, and tighten the nut until you get the specified amount of drag on the pinion. It's basically the exact same procedure you'd use if you were setting up a new ring and pinion. You can do it yourself, it's not particularly difficult, but it's often a very a tedious job. Tighten a tad, check, tighten, check, tighten, check, and when you get the pinion set, make sure you double check the ring gear backlash and wear pattern. Theoretically it shouldn't have changed, but it very well may have.
Last edited by Bugman Jeff; Mar 16, 2010 at 10:35 PM.
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Melting Slicks
Joined: Jul 2006
Posts: 2,266
Likes: 478
From: Salmon Arm, BC
for a quick fix there is a complete rearend in the parts section $400.
Here's a link
http://forums.corvetteforum.com/c3-p...ete-400-a.html
Here's a link
http://forums.corvetteforum.com/c3-p...ete-400-a.html
Race Director
Joined: May 2005
Posts: 10,674
Likes: 121
From: Millington Illinois
St. Jude Donor '08-'09
That is the problem. You crushed your crush sleeve that sets the preload too much. You will have te resetup the ring and pinion. It has to come apart, check everything, new crush sleeve Ect.. The crush sleeve acts like a lock washer and the more you tighten it the more the pinion moves into the housing. You install a new one and tighten it gradually checking the gear mesh until it is right and your done. The sleave has crushed at this point and the nut won't back off on its own. Once you loosen that nut the crush sleeve is done and will need replaced. You very well could have trashed your ring and pinion already.
Last edited by 63mako; Mar 16, 2010 at 11:47 PM.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Safety Car
Joined: Oct 2006
Posts: 3,930
Likes: 15
From: Calgary Alberta
That is the problem. You crushed your crush sleeve that sets the preload too much. You will have te resetup the ring and pinion. It has to come apart, check everything, new crush sleeve Ect.. The crush sleeve acts like a lock washer and the more you tighten it the more the pinion moves into the housing. You install a new one and tighten it gradually checking the gear mesh until it is right and your done. The sleave has crushed at this point and the nut won't back off on its own. Once you loosen that nut the crush sleeve is done and will need replaced. You very well could have trashed your ring and pinion already.
You are now just tightening the bearing up against the race...if you run it like that, you will burn up a bearing, and destroy your whole diff. Time for a rebuild...there is no way to avoid it.
Platinum Supporting Vendor
Joined: Sep 2001
Posts: 3,665
Likes: 340
The diffs are pretty tough, but your done. If you have been driving it like that, remove the diff and fix it right or you will be buying a new R&P and paying someone like me to build a diff for you. I don't even know what you have is worth fixing now, but you can try. You will need a new crush sleeve and you will have to remove the diff from the car. Once you have the new crush sleeve in place, you can start tightening the nut with your impact until you feel a very small amount of play. Once you have done this then you just want to bump the impact and check the torque with a ROLLING TORQUE wrench. You need to tighten the nut until you have 15in/lbs of rolling torque. Once you get this, stake the nut and you are done, reinstall the diff. Don't forget install the oil seal, and pack the back of the seal with grease.
Justin
Justin
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Not necessarily. These guys are doomsdayers. Just tightening the pinion nut would not change the position of the pinion itself. It just tightens the bearing reload. Over tightening would wear the bearings and make noises under all conditions. The symptoms that you have would indicate a pinion that is loose. Go back and recheck what you have done. Check the pinion for movement in and out. Check the NEW yoke for compatibility.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 121
From: Millington Illinois
St. Jude Donor '08-'09
Not necessarily. These guys are doomsdayers. Just tightening the pinion nut would not change the position of the pinion itself. It just tightens the bearing reload. Over tightening would wear the bearings and make noises under all conditions. The symptoms that you have would indicate a pinion that is loose. Go back and recheck what you have done. Check the pinion for movement in and out. Check the NEW yoke for compatibility.
http://www.duntovmotors.com/63-79Dif...plodedView.htm
Last edited by 63mako; Mar 17, 2010 at 11:50 AM.
Thread Starter
Instructor
Joined: Mar 2010
Posts: 205
Likes: 2
From: Sneads Ferry NC
So should I go with this...
http://forums.corvetteforum.com/c3-p...ete-400-a.html
Or should I try to rebuild it? From the sounds of it, it seems rebuilding it may or may not fix my problem and I have never rebuild a diff. What do you guys think?
http://forums.corvetteforum.com/c3-p...ete-400-a.html
Or should I try to rebuild it? From the sounds of it, it seems rebuilding it may or may not fix my problem and I have never rebuild a diff. What do you guys think?
Le Mans Master
Joined: May 2002
Posts: 5,084
Likes: 786
From: Lebanon Township New Jersey
Forget about rebuilding it yourself. You need micrometers, dial indicators etc and a lot of experience to do it right. Buying the unit posted will be cheaper than having yours rebuilt professionally.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 121
From: Millington Illinois
St. Jude Donor '08-'09
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.