Rear Wheels

[Vette79]

I topped of the fuel tank yesterday and after parking the 79 L48 in the garage I noticed that the rear end was squatting. The top of the rear wheels were pointing inwards and the bottom of the wheels outwards. The shocks and leaf spring have been replaced. I imagine the wheels right themselves when moving. Is this normal?

 

[black_81_vette]

If its not excessive I wouldent worry, but if the tires are wearing out on the edges and theres noise then theres a problem.

 

[Vette79]

No noise or any indications of problems other then the appearance at this point. Is there an adjustment that can be made to correct this problem?

 

[MikeMc71]

It sounds like you need to adjust the camber in the rear. If you get the AIM or service manual, it is pretty straight forward, somewhere on the CAC or CF there is a good description of the procedure. AHH here it is:View attachment 14258

 

[6880 Mike]

It's probably an optical illusion. My 74 always seemed to squat using eyeball scale. It's the way the fenders wrap under. If your rear camber was out far enough to actually tip in the tops of the tires, you'd be getting horrendous tire wear and the rear end would be twitchy.

 

[Vettehead Mikey]

I don't quite agree. Correct rear camber should make the rear tires appear to be vertical to the eye. If you can 'see' some tipping inward, get the alignment checked. It could be bad alignment, or possibly worn stub axles in the diff.

 

[Vette79]

Mikey, you mean side yokes?

 

[Vettehead Mikey]

yokes it is!

 

[6880 Mike]

I don't quite agree....It could be bad alignment, or possibly worn stub axles in the diff.

Checking rear camber doesn't hurt, but if the rears are out enough to appear to be leaning in, he'd see the tire wear and feel it when he drives.

 

[Vette79]

So far I have no unusual tire wear or noise. It rides well.

 

[6880 Mike]

So far I have no unusual tire wear or noise. It rides well.

Doesn't hurt to check, but I'm betting your rear alignment is fine.

 

[Vette79]

I used a floor jack and put one rear wheel up at a time to check for play. I can push in on the top of the wheel at least a half of an inch. Time for side yoke replacement? How can you tell if the side yokes need replacement? What if you don't replace them if you need to?

 

[The73vetteman]

I can push in on the top of the wheel at least a half of an inch.

I'm not sure this is a yoke problem but it's definitely not good. I'm thinking bearings. What does everyone else say?

J

 

[Vette79]

Bearings have been replaced. Less than a year old.

 

[bmotojoe]

What condition are your strut rod bushings in? and U-joints? There is way too much movement someplace. I would think if the bearings were that loose you would have spin a bearing by now and there would have been noticeable noise coming from the rear especially when making either a right or left turn.
If the rear wheel bearings were shimmied correctly they should be between .001 and a maximum of .008 endplay.

 

[Phill]

can you post a pic to see how much the tire is leaning inward.

 

[Vette79]

What condition are your strut rod bushings in? and U-joints? There is way too much movement someplace. I would think if the bearings were that loose you would have spin a bearing by now and there would have been noticeable noise coming from the rear especially when making either a right or left turn.
If the rear wheel bearings were shimmied correctly they should be between .001 and a maximum of .008 endplay.

The bushings seem OK but could be replaced. U-joints could stand to be replaced as well. I only have play pushing in on the upper portion of the rear wheel. When I push in I can see the side yokes going in to the differential.

 

[Vettehead Mikey]

How can you tell if the side yokes need replacement? What if you don't replace them if you need to?

Have a helper rock the wheel while you look and feel how much the yoke is moving in and out of the diff. If it's more than 1/8" it's time to think about replacing them. Make sure the car is properly secured on axle stands before you go underneath.

Continued driving with worn yokes will not cause any safety issues (contrary to some opinions) but the problem will get worse and worse as will the cost to fix.

If it's not the side yokes, then examine each component in the drive train to find the source of free play.

Try rocking the wheel by holding it at the 3 and 9 o'clock position, this will help isolate bearing play from yoke or strut rod issues.

 

[Vette79]

Mikey, the play is definately more than 1/8''. I have tried rocking the wheel from the 3 and 9 o'clock position with no play at all. The 12 o'clock position is where I get movement. I will try and post a photo later...

 

[bmotojoe]

By the description of your problem I think you answered your own question. The stock side yoke ends do wear down over time and this is normal. I removed mine years ago to inspect and replace the side yoke seals because one was seeping fluid. Not that bad of a job once you get the exhaust, rear spring and half shafts out of the way. When I was in there I replaced the side yoke bearings and snap rings with new, also new cover gasket, fluid and additive. You will have to have snap ring pliers with 90 degree tips that fit your new snap rings properly. This may also be a good time to replace your u-joints. IMO, It may not be a safety issue now, but remember that depositing damaging metal into the rear end from side yoke wear could cause other issues down the road.
Brian