CentralCoaster

I don't have any play in mine. I feel for movement between the rotor and caliper bracket. Nothing else but a loose wheel would cause play here.

The bearings I trashed had between .002 (marginal) and .008" (knocking loudly) of lateral movement at the hub flange.

Z~max

Sorry guys I have an extra zero on all these numbers.

I did call a friend and he came to look at it after work. While we we trying different things, I took out the washer in between the spindle flange and the back of the bearing just to see. Trying to save a little time I grabed the impact gun and lightly tightened the axle nut. It was what I thought was about as tight as a lug nut that I would send down the road.(about 100lbs.-ft.) Low and behold all the play was gone. I then decided to back the axle nut off and torque it to spec this time, 166. There was the play again.

So we start looking for tech bullitins just to see. We happen to find one stating 84-94 vettes 182-195 lbs.ft. So I torqued the axle nut to these specs and still had the play. I kept loosening the nut and retorqing to higher specs and finally stopped at 240. This took out most of the play, but it was still there. I am going to get new washers for behind the bearing and start all over again.

Still going Time for some

Tom Piper

When you look at the movement at the outer edge of the wheel, .005" of wheel bearing play feels like a substantial amount -- in fact, to someone not used to checking it, it feels excessive.

I just went through this on my 1964 Corvette where you adjust the rear wheel bearing play with shims. The acceptable tolerance is .001" to .008" on a dial indicator at the axle centerline. These bearings are preloaded like a differential pinion bearing and torqued to 100 ft lbs.
I'm not sure about a C4, but on a C2, you do NOT want zero play. The play is checked with the half-shafts disconnected.
The result:
.001" of play when checked by pulling the outer edge of the tire feels questionable, but it isn't.
.008" when checked by pulling on the tire feels downright dangerous -- you might say "disconnected."
I could set the play anywhere I wanted it, but I went with .001" simply because it "felt" better.

If you really want to know what the play is, take the wheel off the car and check the movement with a dial-indicator at the axle centerline while pulling in and out on the axle.
I think you will be suprised how little play there really is.

After setting up my C2, looking at when I changed the rear bearings on my '92, it wasn't even close to being needed done.
I suspect that many, if not most, C4 wheel bearings are changed when it isn't necessary.

My suggestion:
If you think your C4 wheel bearings need changed, don't pull on the tire at 12 and 6 O'clock.
Use this criteria:
1) Do they make noise?
2) With a dial-indicator on the axle centerline, is the play more than .003"?
If you can answer yes to either of these, it is time to replace them.

I think many of the "new" wheel bearings that are being questioned are within factory "new" tolerance.

Tom Piper

mik

I replaced the rears with Timkens from Autozone. Zero play. The originals had play. That's why I replaced them.

Z~max

Okay, one more question for the guys that have no play:

Did you do the work yourself? (Not a question of your ability)

Was the axle nut tightened to spec with a torque wrench or just slapped on with the impact gun?

Okay that was 2 questions, but I am just curious. Thanks for everyone's input this is a great site!!!!

Tom Piper

When I put the new rear bearings in my '92, one had some minor play and one didn't -- I torqued both to the "correct" spec with my 3/4" torque wrench that goes above 200.

But, looking back, my old bearings didn't have any more play than that one new one. I really didn't need new bearings.


Tom Piper

CentralCoaster

Replacement SKFs had zero play off the car and when installed and torqued, you could feel the preload when turning them by hand, unlike the worn ones I removed. I measured the play of those while off the car.

I torqued the new ones to 160, highest my tq wrench goes to. haven't rechecked since.

dizwiz24

I want to share with you an experience on the front rotors of my 93...

When I replaced the rotors, and rotated the rotor it appeared warped! wobbling from side to side at 2 given circumferential positions.

I even had 2 lug nuts on the rotor to ensure it was flat against the hub

At least I thought it was flat on the hub...

I ended up putting the rim/tire back on and tightening all 5 lug nuts down.

I then took off the lug nuts, rim/tire, and spun the rotor.

Lo and behold all the play was gone. Something got pressed in properly when I put the tire/wheel on there and tightened it down..

Hope this helps.

jrzvette

Why not call Gordon Killebrew and get his thoughts. Isn't he the one who is supposed to know these cars inside and out?

Z~max

Please forgive me, but who is Gordon Killebrew?

C2BOB

You replaced the bearing but did you reset the end play? Inspite of what the manuals say the rear bearing don't get set to .001 to .008 endplay. If you do that new bearings immediately get loose. You need to preload them. I have for years preloaded the rear bearings and have never had any kind of problem. You preload front wheel bearings why not the rears?

Tom Piper

I know already that there are going to be some that disagree with this; but, for what it is worth here is my opinion:

On my '64, for the rear wheel bearings, I can adjust the play with shims. I can also adjust the torque (clamping force) on the bearing inner races (but not on the bearing rollers, unless I screwed up and didn't put enough shims in for the required .001" to .008" of play) with the axle nut.

On my '92, for all the wheel bearings, you cannot adjust the play or preload -- this is all determined when the hub assembly is manufactured -- it is one assembly when you buy it.
When you tighten the axle nut, you are determining how tight the axle is held in the hub (inner part) of the bearing assembly -- it does not adjust play.
What may make it seem like you are adjusting the play is the fact that the halfshaft/differential link is becoming more rigid with the hub and bearing assembly.
If you really want to check the play without interference, you would have to disconnect the u-joint at one end of the halfshaft. Then, check the axle (in and out) movement with a dial indicator.

With my '64 and '92, it is not a good indicator of play by grabbing the wheel/tire at 12 and 6 O'clock and moving it.
The '64 has a three link rear suspension; the '92 has a five link suspension. On both, the halfshaft is one of those links. When the axle nut is tightened, it is causing the axle to become rigid with the halfshaft link and that will interfere with the movement. By disconnecting a u-joint on the halfshaft, the axle and bearing are held together tightly, but the halfshaft does not prevent movement. Also, the brake assemblies should not be in place, because they can interfere with the movement.

Tom Piper

jrzvette

Most knowledgeable C4 person on this earth. Runs C4 clinics in Tennessee and is available for consutation via telephone.

Vette Threat

You could always bench test it. That would eliminate all other factors.

Tom Piper

Very true.

Carefully mount the hub in a vise and check the wheel lug flange movement with a dial-indicator.

Buy a dozen, bench test and select what you want, and take the rest back.


Tom Piper

spinktec

I replaced my left rear wheel bearing with an Advance Auto assembly ($184.00). I did it because I heard a clunking when I went over a bump. When I heard the sound I pulled the car to the side and was instantly able to tell the bearing was bad with the car on the ground just by grabbing the top of the tire and shaking the car back and fourth. I drove it home, jacked it up, and felt the worst bearing I've ever felt. The runout measured at the top of the tire was probably 1.25 inches! It took me two days to get the bearing and 45 minutes to put it on lying on the ground. The axle nut wasn't even finger tight, but the cotter pin was in place which means the bearing was compressed inside. Sure enough when I took it out the the hub assembly fell apart in my hands. I put the new one on without a torque wrench. The truth is, I've not used a torque wrench on axle nuts for a decade plus; I just jump on the breaker bar 'till it feel like it doesn't want to move, loosen once then jump again (I do this with the wheel on, the car on the ground, hub cap removed). I admit this was my first Corvette axle, but I've done at least 75 other types in my life this same way. With the new bearing installed, and the wheel and tire on I could not detect any play at all. However, I think that old bearing killed my outer U-joint!

Regarding the play issue above, I would start by using a micrometer to measure the inner bearing diameter versus the outer diameter of the axle. If we suppose that the bearings are ok the only place there can be play (disregarding any suspension movement) is between the axle and bearing or the mounting of the hub assembly in the axle housing. I don't believe I've read either discussed here.

MilehighZ51

Z~max

I do tend to agree with this. That is why I am leary of just trying to crank on the axle nut to take up play. I have done that on some front drive cars and it has removed the play, even though it should only affect the inner race. The movement I am getting is cocking the inner race to the outer race. Not keeping them parallel to each other. This movement would mean the bearing is riding more on the edge than on the surface. I just think that would lead to some really bad premature wear.

What I think is odd is the front is a sealed hub too and it doesn't have play, it feels solid as a rock. Other than the axle being in the middle, the rear should be the same. I also feel the bearing should be tight even without the axle being present at all. The axle is a suspension link too, along with driving the wheels, why wouldn't you want to mount it in a solid point? It has double duty.

At least I am going to the ALMS race at Mid-Ohio next weekend. Go Corvette!!!!!

Tom Piper

What if you could bolt on heavy duty C4 rear wheel bearings?

I have a theory that depends on what I heard and what I remember being correct.

I've heard that the C4 rear wheel bearings are the same wheel bearings that were used on the front of the A-body (Pontiac 6000) front wheel drive vehicles in the '80s-- I've never confirmed this.

If my memory is correct, I had an '82 Pontiac 6000 that had standard ball-bearing wheel bearings on the front. And, later I had an '85 Pontiac 6000 STE that had heavy duty tapered roller bearing wheel bearings on the front.

I wonder if the rear wheel bearings on the C4 uses the ball-bearing wheel bearings that could be replaced with the tapered roller bearing wheel bearings, and it would be nice if they simply bolted on.

If someone has access to the some auto supply wheel bearings, it would be interesting to put a rear C4, front standard Pontiac 6000, and a front heavy duty Pontiac 6000 wheel bearing side-by-side to compare them and the part numbers to see if it would work.

Tom Piper

the blur

I take back what I said eariler above. 265 track miles on my autozone Timken front bearing, and it is garbage !!!!! 1 lousy event and I have to do the job over. This bearing became so sloppy it is ridiculous !!!

I might put the OE bearing back which only had a little play.
so much for timken. any other brands ??