rear end side yokes

L82 Shark · 11-02-07, 12:08 PM

We just purchased this 79 L-82 Vette sight unseen and it is in really good shape for being all original and documented but the camber on the rear tires is starting to look like the rear of a 1960's VW bug. I know that the side yokes were a problem and that these ones have no more adjustment left at the lower eccentics and must now be replaced.

I have two questions: First is, does anyone have time to explain how to remove the rear end or is there a site I can look at that shows the steps for removal.

Second, Once I get it out how do I remove the side yokes and what do these wear on. Does that part have to be replaced also?

Do you prefer new yokes or the rebuilt ones with the pressed in hardened tips?

Any help would be appreciated. I use to be a mechanic but I only worked on a few Corvettes and never on a rear end.

GTR1999 · 11-02-07, 12:58 PM

How much play do you have? You may find the strut bushings along with the yokes worn or possibley the strut rods bent.

To remove, this is how I do it:

remove exhaust- good time to upgrade to 2.5 duals
remove spare tire tub
mark the camber position on the rod nuts so get it back close
remove camber bolts and move rods out or down
remove the dirve shaft yoke strap
remove the 1/2 shafts
I use a tranny sissors jack under the diff to "catch"it
remove the bolts in the crossmember to frame
use a bar and leverage to break the crossmember and diff loose from the frame and rest on the jack.
Lower out

To replace the yokes, remove the cover, up to 2 qts of nasty gear oil and look at the snap rings on the end of the yokes.
If the snap rings are gone then the yokes are really worn. Look at the side of the diff where the yokes go in. There should be a 1/8 boss there. If real bad the yokes will grind into this and hit the seal. If that happens then the carrier is shot.

If you go to the other corvette forums I have a full pictorial on all your questions that will help you.

Keep in mind the weak areas of the late 76-79 diff's- ring gear bolts, posi clutches, and yokes. They all need to be addressed while you have it out of the car. With some time and parts you can make it much better then new.

L82 Shark · 11-02-07, 01:33 PM

The drivers side has next to no play but the passanger side has at least 1/4 of an inch play. Also on the drivers side the adjustment is all of the way end.

GTR1999 · 11-02-07, 04:34 PM

.250 is way too much and needs to be addressed. If you go as far as replacing the yoke replace them both. You may pick up a lot of play in the posi. With the yokes out install the snap ring and measure from the face the ring. Should be in the .180 - 187" range.
What adjustment are you referring too? Camber bolts?

L82 Shark · 11-02-07, 04:42 PM

Yes, the ones on the lower arms right below the half shafts

L82 Shark · 11-02-07, 04:54 PM

When I told the wife about what you said about upgrading the exhaust she gave me the deer in the headlight look. If I were to do this what system do you recommend. I would want something that made some noise when you get on it but once a cruise speed was reached it needs to be calm for the little ladys sake. Like I said this has the factory exhaust still but I would want to go with a true dual exhaust.

GTR1999 · 11-02-07, 05:42 PM

I've run chambered - didn't like the fit or the noise
Have Flowmaster 50's on my 72 and it's not bad yet sounds good to me.
My son has Flowmaster 40's on his 75 and they are loud.
It really comes down to personal preference. Too bad we're out of driving season yo could go to some shows and hear various exhaust.

GTR1999 · 11-03-07, 08:22 PM

I just finished a 1970 diff with a tuned posi and had to grind .005 off the original yokes to reuse. I set the endplay to .005-.010"
The later 70 yokes are usally not good to reuse but the yokes from 73 down can be reused a lot.

L82 Shark · 11-08-07, 09:50 AM

Just wanted to give an update. While doing the initial check of the rear end I knew I had a lot of movement and it looked like it was the yokes but now that I have taken the rear of the car apart I found the real problem. The yokes on both side move maybe 1/32 of an inch by hand with the half shafts out. The real movement is cause by the strut rod bushings being gone. There was no rubber part left to the inner bushings. This will be a much cheaper fix but I did find one bad U joint also.

I am also going to replace the rear spring since it is 30 years old and did not need to be compressed to remove the attachment nuts.

68Roadster · 11-08-07, 10:14 AM

Congrats on "cheaper" fix.....
Are you going with fibreglass spring?

L82 Shark · 11-08-07, 10:26 AM

I would like to but the price is a lot more and the wife wants me to keep it all original equipment since this car has not been messed with. Do you have a fiberglass spring in yours? How do you like it?

L82 Shark · 11-08-07, 10:32 AM

I also wanted to add that after finding the problem with the bushings I plan to replace all of the rubber parts in the rear of the car and then the front will be next.

68Roadster · 11-08-07, 03:12 PM

Quote:

Originally Posted by L82 Shark

I would like to but the price is a lot more and the wife wants me to keep it all original equipment since this car has not been messed with. Do you have a fiberglass spring in yours? How do you like it?

It has had the fibreglass spring since I owned it so I don't know how it sat or rode with the old style metal spring. The ride is OK.

I too went thru the front and back replacing all the worn rubber.
Trying to remember one of those words of wisdom that popped up during that exercise....something about torquing the rear spring back in, can't remember if it was weight on or off the car when you install so that you don't pop the ears off the diff cover....

Have fun...I did!

black_81_vette · 11-08-07, 10:49 PM

The car has to be sitting on the ground before you tighten the spring bolts .

L82 Shark · 11-26-07, 11:17 AM

Just a little update. I have installed all new rubber bushings in the sway bar links. I also installed a new steel spring with bushings. It was amazing how much arch had been lost from the old sping The car now sits 2 inches higher than it use to. If we hit a large bump the tires use to rub the fenders.

Th last parts that I replaced now takes away from all original but makes it much easier to keep the rear alignment set. I installed the poly adjustable strut rods. They adjust like front tie rods with a sleve instead of using the eccentrics and they are easy to install. The rear end is all snug again and the car does not drag it butt.