Rearend whine, what's with these shims? Pics. Help!

blackened88lx

Active Member
Aug 9, 2006
0
4
28
Connecticut
My rearend started whining a couple weeks ago, quiet at first, only in 4th gear under very light throttle. It slowly got louder, and I can now hear it in 3rd, 4th, and 5th, but still only under very light throttle. I pulled the cover today, and there are shims sticking out of the left side. They are kind of loose in there, I can move them around with my fingers. On the right side, they look like they are where they should be, but I poked them, and I can move them around a little bit. I checked the cap bolts, and the ring gear bolts, and they are both tight. Any help would be appreciated.
Thanks
Here's a pic
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Edit: The gears are pretty new, they are 3.55s that were installed at a dealership by the previous owner of the car. I'm guessing they have less than 3k miles on them seeing how he never drove the car.
 

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Pull the carrier and inspect the bearings... Those shims SHOULD NOT have slipped out like that. With the shims out of place, you have excessive backlash and that is causing the whining.
 
beat me to it......you can tackle the job yourself but you will need the tools and patience. I have had 3 rearends put in for me and only 1 of them have been acceptable. I say its very crucial to have a expierenced mechanic who will take thier time installing. Sorry but i have a bad taste in my mouth from previous experience..
 
Thanks guys. I put very little miles on the car after it started whining, so I hope the gears are okay. I'll just run 'em either way. I wasn't planning on doing the job myself, I know it's involved. I have access to the tools, and I'm sure I could take my time and figure it out, but I don't wanna deal with it. Even though I didn't pay for the install because it was done before i bought the car, it kinda makes me mad that a shop could be that incompetent.
Edit: After reading through the link jrichker posted, it looks like my shims are in the correct spot, but falling out for some reason...
 
Check to make sure the caps are not put on the wrong side or upside down. I think the are supposed to be offset a little. They should cover the shims and not allow them to fall out like that. When I did a couple of rearends a while ago, I used one solid shim of the correct thickness, instead of a stack of thin ones. The ford dealer had a ton of different sizes in stock.
 
the shims are in the right place. they go between the housing and the bearing race. probably what happened is the guy who did the rear end didnt have a case spreader and couldnt get the correct preload in there. you have to preload the rear end and than put an extra .003-.004" on each side of the carrier so when the bearings break in and wear the shims take up the space. seems like someone didnt know what they were doing or just didnt want to take the time to do it. a good shop would only use two shims on each side. they would find a big shim that would give the rear end the right backlash and preload and than use an extra small shim to get the extra .006-.008"