The Stovebolt Site Forums The Shop Area General Truck Talk Bad bearing? (51 half-ton)

We just finished installing a power front disk conversion and went with the upgraded tapered wheel bearings. Now it sounds like I have a bad wheel bearing except that zig-zagging has no affect on the sound, a kind of high pitched rattling noise.

The sound comes on at about 15-20 mph regardless of what gear it's in with the clutch engaged or not. Turning the wheel by hand doesn't show any grinding symptoms or irregular rotation and the wheel is snug, no slop or wiggle.

Before we take the thing apart and replace a brand new wheel bearing is there anything else it might be?

Possibly a backing plate/dust sheild rubbing the rotor? I've seen that happen on late models.

No, there's no dust shield or other part touching the rotor. But thanks anyway.

Just a thought, I wasn't sure if a sheld cam ith the kit you used.

Jack up the front wheels & spin them. A bad wheel brg will make a grinding noise &/or be loose. Could it be comeing from the drive shaft or rear end?

We did the usual test, spun the wheel by hand and it did not show any of the usual symptoms. When we test drove it we zig-zagged it and didn't get any change in the sound.

It's definitely not coming from the rear end... the sound is near the front and can be felt in the steering wheel at just a very narrow speed range.

How would you troubleshoot the drive shaft?

Thank you for any help.

Are you using the stock wheels from the 51 on this disk conversion?? You may have a clearance problem between the claiper and the stock steel wheel.

(41 chevy) is right on the money the calipers are rubbing the rim.To trouble shoot the drive line you have to pull it out and check the u joint and take in to a drive line shop to check the balance.Hope it helps you.

It's not the wheels... I bought a set of 4 new from Wheelsmith as suggested by CPP. The photos on my website do not show the truck with the new wheels and caps. There is nothing rubbing the calipers.

The truck rolls out freely until it reaches 15 mph and then the noise begins. Plan is to get it off the ground and run it in gear to see if it's the drive train which exhibited NO unusual noise before the brake job.

The brakes work great! It's nice to not have to adjust my braking habits between vehicles. I just put my heel on the floor and gently push the pedal with my toe.

All we did was change out the front brakes to disk, completely restore the rear brakes and installed a power boost dual master cylinder and proportioning valve. PCC markets the whole package as a kit so everything came from the same vendor. More on that later.

There was absolutely no way the stock 15-inch wheels would clear the calipers so I went with the CPP suggestion and bought four new wheels especially made for the CPP disks from a company named Wheelsmith. They are called "smoothie" and look pretty stock (my goal) especially because Wheelsmith also sells a baby moons that look just like stock hubcaps right down to the embossed CHEVROLET script and red lettering. The wheels have 3 "bumps" on the rim that the caps snap down on, and are beautifully made and spun as true as I could have wished. They do not touch the calipers... we removed one and there was no sign of contact with anything... the paint was untouched.

Like I said, we're going to get it off the ground and run the drive train to check to see if it's coming from there.

My mechanic is an ASE Master Technician with 33 years experience building race cars and street rods with a completely equipped shop so we can rule out any amateur blunders.

Other than that, don't know what else there is to say.

Cz...If you have installed bearings then you know if the bearings are OK and if nothing rubbing take a good look at tires...doc

Good idea on the tires... I'll add that to the list of things to try and move them around to see if that's it.