johnfl

2001 Impala LS 115,000 on clock.
I have vibration and grumbling coming from the front end of this thing. At 1st I figured it was the wheel bearings since the ABS light has been on forever. I lifted the car and ran it in gear and have no noticeable noise from the bearings or axles. There is no seemingly excessive play in the wheel bearings when I check for play with the front up on jacks but I get nasty vibration under load on even slightly uphill acceleration especially on the freeway. It's getting worse as time goes by and I am noticing a little rotor vibration in the peddle now, originally it only had the nasty vibs when accelerating around curves on an uphill but no peddle wiggle.

What is the best way to eliminate the halfshafts as a contributing vibration source?

I've had the ABS and TRAC warnings on for quite some time (months). If I turn off the TRAC I don't have any problems as far as the stutter on acceleration. I live in Phoenix and am dragging my feet waiting for the temperatures to drop a bit below char-broil before I get out there sweating my azz off changing out hub assemblies.

JohnF
Phoenix (The Oven) Az.

EinST

Welcome to the forum. Before contemplating extensive diagnostics, have you tried rotating the tires front to back? Sometimes tires cause vibrations only when they are under load that feel like bad wheel bearings.

johnfl

The tires are in good shape, no weird wear signs but they are due for rotate/balance. I was planning on getting that done in the next couple weeks.

thx

JohnF

RickMN

The bearings would have to be really bad to cause vibration. Usually they cause a low resonating humming sound that gets a bit louder on turns. The outer CV joints can be trickier to diagnose. The common test is to do a tight turn in a parking lot and listen for clicking sounds. You get that sound once the boot is broken, the grease has leaked, out and the steel ***** have worn to the point where there's slop in the joint.

However, the inner joints CAN cause the kind of vibration you're talking about. The problem is there's really no good way to isolate the problem except by replacing them. I had a customer's car that did exactly the same thing as yours. I put my electronic stethoscope on the steering knuckle (see this post) and didn't hear a thing. But there's no place to attach an electronic scope to detect inner CV joint noise. Customer said ok to the replacement and the problem went away.

So, it looks like you're into replacing the hubs, no matter what to fix the ABS problem. Rebuilt half shafts are only about $80 each and you'll already have the axle nut off. The only other thing you have to remove is the ball joint. If it's driving you that crazy, maybe it's time to bite the bullet and replace them.

johnfl

Thanks, Rick. That sounds a lot more like what my problem is anyway. It's getting worse by the day and the vibration is HARD. I know about clicking CV's from my years off roading VW's but I get none of that at this point. I do worry about damaging the bearings in the tranny with this vibration, it had to be rebuilt at 45k for the outer bearings already. Far as costs go I shop online for everything even local Autozones/O'Reillys etc so I guess it's time to jump into this thing....if only it weren't 110 outside right now.

JohnF