2002 Grand Prix new CV and Hub bearing noise

[surds]

Hello All,

2002 Grand Prix GT 3.8L

I've recently replaced my left CV axle and hub bearing but continue to get a loud chatter/binding noise when turning sharply left or hard right when in reverse.

The problem started approx. 4 months ago when i would get a loud clunk occasionally when accelerating hard, so I avoided accelerating hard and suspected the CV axle.

Recently the brakes started to fail, sometimes the pedal going down 30-50% more than normal, 2 days later the front end started to vibrate badly and I parked it.

Once I had a chance to inspect it, there was no doubt excessive play in the left (DS) Hub assy and the inner boot had some grease below it on the frame. I purchased an Econo axle shaft complete and hub assy and replaced which seemed to go together well. Pads, calipers and rotors all seemed fine, although I didn't have a dial indicator to check for run out on the rotor.

I did not have a torque wrench for the axle nut and was little concerned when it tightened up and felt like it was bottomed out, I don't think it was any more than 120 ft lbsto get it there but I don't think 500 ft lbs would moved it any further.

Anyways the brakes seem worse now and ABS seems to be very sensitive with the pressure and effect of the brakes being erractic, sometime I get good pedal resistance but no braking action.

Anyways, I'm going to bleed the brakes today but would appreciate any input on the problem as a whole and possible causes.

Thanks in advance!

Surds

[BNaylor]

Welcome to AF.

No torque wrench for the axle nut? Thats not good.

What brand hub did you purchase?

[surds]

Thanks for the reply BNaylor.

I know , I had a 1/2" torque wrench but the 36mm socket was a 3/4" drive with no adapter in sight. My brother in law insisted he knew by feel. LOL but it worried me when it bottomed out, didn't seem to take much torque to get it there though.

I believe the CV axle was a dynapak but I'm not sure on the hub assy, it was a cheap import at $88 compared to $259 for the step up.

[BNaylor]

Oh well. .....

That probably explains the possible premature failure on the hub which is common if the preload is not done right via proper axle nut torque specs. Also, overtorquing may stress the CV joints on the axle shaft or damage the wheel bearings. And those Made in China hubs aren't too reliable either.

Technically on any hub you should use a new axle nut and for your year Grand Prix torque axle nut to 159 lb-ft and leave it at that. But this figure is for GM OE or AC Delco replacement hubs.

[surds]

Thanks again for the insight.

I see you picked up on the fact that I used the old axle nut, didn't have the 30mm socket for the new nut either.

Well back to the garage..... after I get the right tools for the job.

[surds]

Does it sound like the hub bearing failure is the root cause for the brake problems or could there be a master cylinder / booster issue?