PontiacBonnevilleClub.com

The in-laws' Grand Prix make a good hum that comes up at 25ish mph and is dependent on speed only, and sometimes direction of a turn at speed. While I'm positive it's the LR wheel bearing, is it at all possible that it's anything else? It doesn't change with RPM, so it's not an exhaust hole that it almost sounds like sometimes.

Tire? Try switching the wheels on that side.

A local GP club member has been picking my brain to see if I could diagnose what he'd been chasing for a year. Was getting a humming noise from his lf and had done brake pads, rotor, greased slides/pins, wheel bearing (2 times -both new) and was still getting the noise.
He eventually took the wheel off to get it balanced and they said the tire was almost oval. New tire and the noise was gone.


I'll also keep you updated on what I find -I'm getting a humming sound from my GTP's left rear wheel, but I suspect it's the tire simply based on the condition of the tread (cupping on the inside).

We can't feel any vibrating at all. The sound is not apparent until 25 mph or so.

I'm not getting any vibration either. Same with Mike (JBLNut from MNClubGP). He only had it balanced because he was going on a road trip and had all 4 wheels balanced before the trip.

in 1983 84 don t we rent a foed fairmount over 55 mile per houre start to vibrating
maby wheel where not balanced.was rentel car

On my 2000 Intrigue, I had all four bearings go out simultaneously over the course of last summer/fall. I am 95% sure that's your issue, but jack the car up, grab the wheel, and see if it "wabbles" when you grab an tug as though you were taking the tire off for a change. Usually if a bearing is bad, it has some movement if you pull or push it inward or outward.

I hope my attempt at an explaination makes sense

I'm certain it's the bearing. It looks like they want me to tackle it real soon.

What special tools are needed? Just a puller? How big is the wheel nut? I assume we need a new wheel nut, and are they easy to get? I had to special order nuts for our Grand Am.

IIRC GP wheel nuts are 32MM. I re-used both of mine with no issues. You might want a slide hammer if it's not coming off easily. Both of mine on my Ei with 165k almost fell off. Be sure to use anti-sieze on the bolts and the face of the bearing to prevent it from sticking. Wire brush the face of the knuckle to be sure it bolts flat and flush.

Will a puller (3-jaw or actual wheel bearing puller) be needed? We're doing the swap Saturday.

It all depends on how bad they are. If you have a hammer and chisel, they will do the job too.

A nice 3 lb hammer worked good on the front wheel bearing I did tonight in my buddies 00 SLE. The hub was corroded in there pretty good.

How do I back the parking brake off if it's hanging up?

Now that I think about it... the rear likely doesn't have an axle/wheel nut, does it? No axle, no nut!

Why didn't anyone call me out on that? lol

Got 'er done. It fought us coming off. Had to remove the parking brake cylinder and pound on the back of the plate with a long screw driver and hammer through it's slot. Then got it all back together and discovered I didn't put the parking brake back together right, and had to do a couple iterations to get it adjusted right after that.

No more grinding sound.

I was PM'd for some tips, and I thought I'd share.

The dust shield is sandwiched between the bearing and the knuckle, so it stays put. You probably can leave the parking brake attached unless the bearing won't come off. In that case, there are two T30 torx screws holding it on from the back that are a little difficult to get to. I used a small torx bit and a 1/4" wrench. Unhook the spring, and pull the lever out of the hole to get them out of the way first, then you can finagle the brake cylinder out and the rubber boot. Then you can slip something through the hole for the parking brake to pound on the back of the hub.