curvesman

Noticed my rear tires wearing FAST, rubber all over! brought to get alined and was told rear bearing has to much play? I jack up car and had 1/2 inch play, should I remove the half shaft and look to see if its missing a cotter pin? It is a 1965 with just 1600 miles since being frame off fully restored. I bought the car this way so I never did any of the suspenion work.
Thanks in advance

Powershift

Remove the half shaft and see if the play is in the wheel bearing (I doubt) or in the differential stub axle (more likely).

That much play in a wheel bearing would likely mean the bearing is gone/disintegrated. It is possible the stub axle "keeper: in the differential has failed (or never installed if rear was recently rebuilt).

Larry

curvesman

Sorry but what is a stub axle, in the differental ( is that the rear end?) If so I will have to get the rear checked once I pull the shaft and check the wheel bearing? As you can see I am not the sharpest tool on the work bench but I try!

Powershift

Stub axle is what the inner end of the halfshaft bolts to. The outer end of the halfshaft bolts to the trailing arm wheel assembly.

The archives should have some info on this problem….as it has discussed more than a few times I believe that any end play in the stub axles over about 1/16 inch is considered excessive. This could be due to wear in the differential internals or the "c-clip" stub axle retainer could be broken/missing.

First determine where the problem is………then we can develop a repair plan.

Larry

curvesman

Thanks, I will look into it more now!!

MikeM

When you say 1/2" play, are you talking about grasping the wheel and pulling straight out, straight in? That's end play and can only be done with the half shaft removed.

Or are you talking about grabbing the tire at 12 o'clock and 6 o'clock and rocking the tire in/out at the top and bottom?

If it's the latter condition, some play is normal. Can't tell you exactly how much is normal because my sample size is too small but I do know some cars with good wheel bearings will move in/out approaching the dimension you gave.

I think the figure on the former condition is about .001-.008 end play. You can't detect this play with the half shaft in place and the rear spring attached.

When you get the halfshaft out to check, make sure you don't have a failed ujoint giving you some slop.

curvesman

I am grabbing the tire at 6 and at 12 and there is play, also at 9 and 3 the same. the tires are wearing out super fast on the rear new tires bald in the middle with 30 lb of air, just noticed this weekend after car sitting all winter.

Powershift

Generally rear tires that are bald in the middle = high RPM burn-outs/hole-shots with too much air pressure in the tires. Maybe this is your problem??

Larry

MikeM

I don't know how alignment or loose bearings has anything to do with tires wearing out in the center?

Maybe someone else has another idea?

curvesman

Wish that was the problem never burned rubber with it YET in 1600 miles, also sad to say I have an 07 Z06 which I never burned rubber with also( (from a take off anyway) other gears YES

Powershift

While you are under the car checking stub axle and wheel bearing free play, check also the following:

1. Make sure that the front pivot of the trailing arms has a shim pack on both sides, and that the shim packs are tight against the trailing arms. Perhaps slotted shims were used, and some fell out. This is your rear toe in/out adjustment.

2. Make sure the rubber bushings are good on both ends of the rear strut rods, and that the strut rod adjusting cam bolt (camber adjusting bolt) is TIGHT. You could have bad strut bushings or a loose cam bolt

Either 1 or 2 above will make the rear wheel squirrely and could wear the tires badly. They will not cause a wheel bearing to be bad, but if someone one is not knowledgeable on these old C2 rears, they could miss these and blame the wheel bearings.

Also check the condition of the half-shaft u-joints like Mike M suggested.

There are only so many things that can go wrong. The 4-5 we dicussed above or earlier account for most issues:

wheel bearings too loose or bad
excessive axle stubs end play (free play)
u-joints worn or broken
toe in/out wrong and shims missing
camber wrong and worn strut bushings

Check them out one at a time. A Chevrolet Service Manual for your car is a good and cheap investment.
Larry

curvesman

Got the car on my friends lift today, removed the half shaft and the tire had the same play as before, So I tightened the wheel bearing and that fixed it, did the same on the other side. Everything under this car is new so why the bearings came loose is a mystery to me? Maybe being everything is new they never seated correct and after putting on some miles they loosened?? Anyway hope this did the trick and I will check tomorrow the other things you said being thew car is still there on the lift! Thanks for all the help every one !!!! YOU GUYS ARE THE BEST!

DUB

JUST A HEADS UP!!

If the rear wheel bearings were done correctly...they do not "seat in" so-to-speak. I have had customers bring their cars in 50,000 miles after I did them and they did not show signs of an increasing run-out.

The nut you tighten at the wheel for your rear wheel bearing should have been torqued to 90 lbs/ft...then turn further so you can install the cotter pin.

The bearing run-out should be from .001" to .003" ...but the manual states it can be as much as .008"...but when I do rear bearings..I NEVER send them out with any more than .003". This is mainly for the brake system.

Then I would have checked the rotor run-out to make sure that the spindle is true and you do not have excessive rotor run-out which can effect the brakes.

Then the four bolts that hold the half shaft to the spindle flange get torqued to 60 to 90 lbs/ft...and then bend the tab on the french lock against the flat side of the head of the bolt...which should have been grade 8 bolts with a short shoulder...to hold that torque.

The stub axle coming out of the differential should have basically no in and out play...if the differential is freshly rebuilt. If you have in and out play that is 1/16"...that is too much in my opinion. Later year Corvettes (C4) have a spec that states that .008" is what needs to be achieved or very close to that. SO I do the same on the earlier Corvettes...even though I have not found any specific spec for that.

I do not know if this was information that was needed...sorry if you knew this already.

DUB

rene-paul

IMHO, I do not think you are out of the woods yet. Please get a shop manual and under stand how the spindle is set up in the spindle support. The stub axle has a specfic torque plus the end float [in and out play] in the range of .002 to .008 as read with a dial indicator. Disc brakes like the tighter side. Learn taper roller bearings and why they must have end play.
Brgds,
Rene

rene-paul

DUB, yur fast!

Powershift

Curvesman:

Agree with DUB and Rene. Just tightening the wheel bearings without knowledge of the bearing clearances or condition is a recipe for trouble. The bearings are normally setup using mics and dial indicators, and once set, should be good for years without adjustment.

Not certain what is going on with the rear end of your car. Be careful what you do.

Larry

Mike Ward

Best hold on a minute. The rear wheel bearings are a complex, precision fit assembly. They don't just come loose or not seat properly. If you found the retaining nut with less that 100 ft/lbs of tq on it, the bearings are already toast as are the spacers and spindle.

How much torque did you apply to the nut and how much end play did you end up with?

curvesman

Well to tell the truth I did not use a torque wrench, just tightened until there was no play But tomorrow I will do it over with a torque wrench and when you say how much play did I end up with do you mean shaken the wheel to see if it moves any?? I think I went above my head on this one

Mike Ward

If it took little or no torque to tighten up the clearance, Bubba has been inside the bearing assemble and machined off an essential tight fit between the races and the spindle.

Beware!

As others have said, you need an end play clearance of .001" to .008", no more no less.

redvetracr

did you remove and replace a cotter pin?