Wheel Stud Replacement Affecting Bearings?

[Ludigdrums]

Hi all...this is a thought I had on a brake problem I'm having. My left rear wheel almost fell of a while back, and I need to replace the studs, as 3 of them broke off. Ever since I replaced them, I then started having this brake problem.

So, my thought is (and question)...could pounding on the wheel studs to extract them, mess up the rear wheel bearing adjustment? It seems very likely to me, and the cause for all my braking problems. I just posted this thread about it: http://www.corvetteactioncenter.com/forums/showthread.php?t=44149

Please let me know your thoughts/suggestions...thakn you!!!

- Jeremy

 

[vette-dude]

To answer your question, yes. Pounding on the studs could brinnell the bearings or another possiblity is that you could have bent the axle flange. I guess it depends on how hard you pounded on it, how big of hammer you used, and how big a boy are you?? :bang


Randy

 

[Vettehead Mikey]

Obviously pound on a bearing area is not a good thing, but you may have gotten away with it this time. The actual load path transmits the load via the spindle through the ujoints, half shaft, yoke to the center pin in the diff. There was no force transmitted through the bearing to the trailing arm assuming the trailing arm was hanging freely from the suspension.

Your other post doesn't say what problems you're having with your brakes but it seems you're trying to adjust the real wheel bearings. I guess you've measured the runout and found it's out of spec? If so you need to disassemble the bearing ass'y itself and change spacers. There's nothing in common with adjusting front and rear wheel bearings on a Corvette. That's why the adjustment procedure is mixed in with the assembly procedure.

 

[Ludigdrums]

Heheh, well, I'm not that big of a guy (5'6" at most & 142lbs), but I'd like to think that I can give a whoppin! ;-) The hammer wasn't all that big, a regular sized one, and I used a counter sink on the studs.

Also, the wheel wobbling on the spindle could not have been too good when the wheel almost fell off.

So, do you think they need to be replaced, or just adjusted?

Thanks again!

- Jeremy

 

[Ludigdrums]

Hey Mikey...yeah, I never actually measured the rear runout because you have to dismantle some of the stuff back there, and I didn't understand the readjustment procedure.

As far as the brakes, here's a long thread about it: http://www.corvetteactioncenter.com/forums/showthread.php?p=326564#post326564

As of now, through a lot of trial and error, I pressure bleed the brakes, and they are amazingly good, but when you drive more than a couple of miles, the pedal starts getting soft. Now, once it gets soft, I can pump it a bit, and get some pressure back.

That's really a short version, but I'm pretty sure it's the rear wheel bearings. No sign of leaks anywhere, and when the brakes are first bled, the are totally awesome! And it's not like it gives out right away...it's just the more miles you drive (the more the wheel spins) the more air seems to get into the system.

Hope that sheds some insight, and maybe an answer!

Thanks!

- Jeremy

 

[vette-dude]

I think Vettehead Mikey has it. Just do the adjustment and you should be okay.

Randy

 

[Ludigdrums]

That's the thing...I don't understand the adjustment from the shop manual, because it's mixed in with the replacement procedure. Any thoughts?

- Jeremy

 

[vette-dude]

Someone else just had a similiar problem with their brakes and it turn out they had a bad bleeder screw. They installed the speed bleeders and the problem was solved. The calipers are not the easiest ones to bleed. Do a search and Keyword "brakes" and you will find alot of info.

Randy

 

[vette-dude]

thread on bleeder valve

http://corvetteactioncenter.com/forums/showthread.php?t=43033&highlight=brakes

Randy

 

[Vettehead Mikey]

Hey Mikey...yeah, I never actually measured the rear runout because you have to dismantle some of the stuff back there, and I didn't understand the readjustment procedure.

As far as the brakes, here's a long thread about it: http://www.corvetteactioncenter.com/forums/showthread.php?p=326564#post326564

To be blunt, I think you're just chasing your tail on this one. If you don't measure it, how will you know if it's out of spec? If you want to just take it apart and adjust it anyway, how will you know if it's adjusted properly unless you measure it?

It's very possible that your runout (if any) is due to a warped disk, bent spindle or misassembled disk and spindle assembly. None of these will be corrected by rebuilding the bearings.

Please measure the run out/bearing play and get back to us with the results.

 

[Ludigdrums]

I totally agree with you. Like I said, I was planning on doing just that, however, don't you have to readjust it after you measure the run out/bearing play? That's why I didn't even measure it because I was not totally sure of the reajustment procedure.

What do you mean by "rebuilding the bearings"?

Does this clear anything up?

Thanks again for all your responses!

- Jeremy

 

[Vettehead Mikey]

You can measure run out and play without disassembling the bearing. Removing the half shaft makes it easier to get an accurate measurement. You need to disassemble the bearing area to adjust the play.

 

[Ludigdrums]

Thanks Vettehead Mikey...the manual says to "disconnect outboard end of axle drive shaft drom wheel spindle flange..." which is I guess what you're talking about. So, if I do that, I can just put everything back together without adjusting anything (if nothing needs adjusting)? That's the first step, to measure...but what if I do need to adjust it? That's the procedure that's confusing me...



- Jeremy

 

[JohnZ]

Realistically, there's no such thing as "adjusting" the rear wheel bearings at home; re-setting the axial clearance requires disassembly of the spindle and bearings, which isn't a "home" job. Check the axial play with a dial indicator on the end of the spindle after disconnecting the outer end of the half-shaft; it should be .001"-.008", preferably .005" or less. If it's more than .008", it's time to have the spindles rebuilt.

Your brake problem (good pedal after bleed that disappears after driving the car) is a classic symptom of excessive lateral runout in the rotors, which "pumps" air past the rear caliper piston seals; this is usually further aggravated by excessive rear bearing clearances. Rear rotor total indicated lateral runout (from lowest reading to highest) should be no more than .004", measured with a preload on the spindle so spindle bearing clearance doesn't affect the reading.

 

[Ludigdrums]

Ok JohnZ, sounds good. 1 Questions though...how do you measure the total indicated lateral runout w/preload on the spindle? Thanks!

- Jeremy

 

[JohnZ]

Best way is to have the outer end of the half-shaft disconnected from the spindle flange, tire off, set up the dial indicator on the trailing arm with the probe tip on the inner face of the rotor, push the rotor inboard (to take up the axial play in the spindle bearings), zero the dial indicator, and turn the rotor while pushing it inboard for one full revolution, recording the high and low readings - the difference is total lateral runout. Use the same setup to check the axial play in the spindle bearings - just put the probe on the inboard end of the spindle, zero the indicator, and push/pull the rotor inboard-outboard, and record the readings.