Rear Bearings

[procketus]

Ok, I have another problem, maybe. Got the brakes bled and felt fantastic. Took car for a ride to get some parts. About a 40 mile round trip down the the highway. When I got to the parts store the brake light came back on. Pedal felt bad again. Mentioned this to the guy that owns the store and he asked if I had any vibration going down the road. Yep, it does. At around 70. He told me that the rotor is knocking the pistons back and forth causing air to get in there. Then he told me it probably needs rear bearings. Looked them up in his catalog and there is a tool listed for setting up the rear bearings with shims. From the picture it looks like a stub from a spindle.

Can anyone shed some light on this. I am going back tomorrow to get a new spring and End Bolts from him. If I need these bearings, I'll get them but I have no clue as to what this set-up tool is.

 

[gmjunkie]

Ok, I have another problem, maybe. Got the brakes bled and felt fantastic. Took car for a ride to get some parts. About a 40 mile round trip down the the highway. When I got to the parts store the brake light came back on. Pedal felt bad again. Mentioned this to the guy that owns the store and he asked if I had any vibration going down the road. Yep, it does. At around 70. He told me that the rotor is knocking the pistons back and forth causing air to get in there. Then he told me it probably needs rear bearings. Looked them up in his catalog and there is a tool listed for setting up the rear bearings with shims. From the picture it looks like a stub from a spindle.

Can anyone shed some light on this. I am going back tomorrow to get a new spring and End Bolts from him. If I need these bearings, I'll get them but I have no clue as to what this set-up tool is.

There is more to it than just a set up tool!! This job can and most generally is a pain in the butt for someone that hasn't done it before!! Hell,for someone that has done a few it can be a pain in the Butt sometimes!!:L
The axle stubs come out hard,you will probly will need the special puller,actually a pusher if your doing it with the trailing arms on the car,sometimes you have to take the trailing arms off anyway and press the stubs out with a press!! You'll need a Dial Indicator to set the bearing clearances up,you'll also probly need a shim assortment,Unless you get real Lucky!! Rear bearings on a C2 or C3 Corvette is best left to someone that has done it before!!

PS There nothing like doing the front wheel bearings!!

 

[Curtis]

I did mine and had never done it before. I have the setup tool. It is invaluable.. and like you say, getting everything apart is the hardest part of the job.

 

[GTR1999]

Check the rotor for runout before you pull apart the spindles. You want it under 005" total. Check the spindles for endplay and look up my thread on this job it has the whole deal with pictures on how to do it right and what tools are needed. A lot of places will do these, only a few go beyond a std job.

 

[procketus]

Went and got the spring this morning and picked the owners brain some more about the bearings. He was nice enough to look at it for me and he was happy with the way it looks. So I think I'll leave them alone for now.

On a side note, put the rear spring in this afternoon. Much easier than I expected and it rides a whole lot better. Not great but better. Still wants to go where ever it pleases on side roads. It may be just me not used to the way these drive, I don't know. But on the way home it was not a two fisted white knuckle drive.

Thanks for the info.

 

[Hib Halverson]

Replacing the rear bearings can be a DIY job as long as you have the proper tools and parts.

Doing the rear bearings properly is a difficult DIY job.

There is a lot of information about the 65-82 disc brakes along with rear bearing service at these URLs.

The Big Block from Hell, Part 12
Big Block from Hell, Part 13

 

[Vettehead Mikey]

Went and got the spring this morning and picked the owners brain some more about the bearings. He was nice enough to look at it for me and he was happy with the way it looks. So I think I'll leave them alone for now.

How did he explain the brakes mysteriously going bad? What did you/he do to fix it and ensure that they don't go bad again?

 

[procketus]

Wheel balance seems to be the culprit. When I get up around 65 it starts to vibrate and at 70, forget it. So now I just stay off the highway and hit the side roads. Better scenery anyway. I'll get them balanced as soon as I can and see what happens. Also have to clean off the areas where the wheels and hubs mate up. There is SOME corrosion from it sitting for a while.

 

[Vettehead Mikey]

Wheel balance will not makes brakes go bad. Have you measured rotor runout and bearing play?

 

[GTR1999]

Mike is correct, if you were told weak brakes were from wheels out of balance you were told wrong- either purposely or out of ignorance.

If you have weak brakes find the problem. There is no reason a 65-82 vette disc brake system should not work great, stop on a dime and not leak.

Look at the BF in the master cylinder. If it looks muddy, flush the system, replace the rubber hoses and check for leaks at the calipers. Chances are if it sat for a while you're going to need to rebuild or replace the calipers.

Buy a Motive bleeder and learn how easy it is to do vette brakes. There is no need to use DOT5 BF. Once you get the system leak free, rotors dialed in to under 005 runout, organic pads, new hoses, you can drive and stop anywhere. If you store the car for the winter, just use the motive to bleed the brakes on a spring saturday and you're good to go again.

Do not turn the rotor unless they use an on the car or can verify after installing them the runout is near -0- this would be + a few tenths only. If your rotor mic up ok then use a 100 grit pad on a D/A to break the glaze and wash them with brake cleaner.

 

[Hib Halverson]

Tire out of balance will not cause 65-82 disc brakes to suck air.

There are only three ways that happens
1) Rotor problems...warppage, thickness variation, non-parallelism
2) Excessive rear bearing clearance
3) Caliper piston bore corrosion.

Get ready for some brake work, my friend.