Grand am brake up now terrible vibration (Page 2/2)
fieroguru FEB 08, 08:54 PM
You absolutely need to center the rotor. I gave the easy method to use above.

Welding on the hub is a very bad idea. They are cast iron and welding will lead to fracture.
pmbrunelle FEB 08, 09:29 PM
A Speedi-Sleeve might work to take up the slack, though I haven't tried this.

For the brake project on my Fiero, I got front hubs from Brian Sanburn (sluppy123 on the forum).

He makes the hubs from scratch, so when you order, you tell him what rotor you have, and he makes the hub to fit the rotor without play.
olejoedad FEB 09, 08:46 AM
There needs to be adequate clearance between the inner diameter of the rotor hat and and the outer diameter of the hub, to allow for easy rotor removal in the future.

Centering rings of various sizes are available online and at tire stores.

Edit to add....

When removing the rotor from the stock hubs and turning the OD of the hub to fit the new rotor, the Fiero hub must be chucked using the inner machined face for the bearing race to assure concentricity.
If the hub is chucked on the outer surface, the hub may not run true.

[This message has been edited by olejoedad (edited 02-09-2021).]

Blacktree FEB 09, 05:30 PM
I tend to agree that the hub and rotor need some "breathing room" for heat expansion / contraction, and rust buildup.

Here's an "outside the box" method I used to center the Grand Am rotors on my hubs. I found wheel studs where the shank (the unthreaded portion) was longer than stock. So the shank protruded into the brake rotor. The holes in the rotors needed to be reamed out, to fit. The wheel studs are Dorman part # 610-376. I don't remember offhand, but want to say I used a 9/16" drill bit. If you go this route, you may want to double-check that.
pontiacfierokid1985 FEB 09, 08:57 PM

quote
Originally posted by Blacktree:

I tend to agree that the hub and rotor need some "breathing room" for heat expansion / contraction, and rust buildup.

Here's an "outside the box" method I used to center the Grand Am rotors on my hubs. I found wheel studs where the shank (the unthreaded portion) was longer than stock. So the shank protruded into the brake rotor. The holes in the rotors needed to be reamed out, to fit. The wheel studs are Dorman part # 610-376. I don't remember offhand, but want to say I used a 9/16" drill bit. If you go this route, you may want to double-check that.



I used lugs from a h3 hummer as I did on all my Fiero’s this is the only one that has been giving me this vibration problem. I’m gonna get regular style lug nuts that fiero originally came with these cars. I have some weird chrome style and feel like these could be a problem also.