Front hub removal

[Rex T.]

Can the front hub (the part the wheel bearing resides in) be romoved from the rotor in order to replace the worn rotor? Thanks in advance for your help.
Rex #8089

[Mike M.]

Re: Front hub removal

what year? mike

[Rex T.]

Re: Front hub removal

1981

[Terry F.]

Re: Front hub removal

In most instances answer is yes. If it is C2-C3 with disk brakes. I am not familiar with later cars. You can drill and punch the rivets and then put on a new disk. I would take it somewhere and have it turned as a unit. Or, I would just send it to Blair's and have them set it up for you. MHO Terry

[Terry F.]

Re: Front hub removal

Read my other post. Terry

[Chuck S.]

Really??!!...The FRONTS??...Rivets?? *NM*

[Mark #28455]

check the runout

After you remove the disc from the hub, glass bead the machined mounting surface where the disc attaches to remove any rust. Get a good quality replacement rotor and attach it using 2 lug nuts. Using a cheap magnetic mount base and a dial indicator ($20-30) check the rotor for runout. You will likely find that if you rotate it through the 5 possible attachment positions relative to the lugs on the hub, one will have a much lower runout. As long as it is in the range of 0.001" don't bother to machine the rotor. Mark it and always keep it in that orientation. I have been lucky enough to get 2 car sets to match up in this way.
Mark

[Joe L.]

Re: Really??!!...The FRONTS??...Rivets??

Chuck-----

Yes, all 1965 through 1982 Corvette original front rotors were attached to the front hub with rivets (exactly the same as the rear rotor attachment to the spindle). The difference is that the fronts were once available from GM as a complete rotor and hub unit; the rears were never available as a unit with the spindle.

GM discontinued the front rotor/hub units for both 65-68 and 69-82 quite some time ago. Riveted assemblies or 1 piece assemblies (rotor + hub as one piece and not riveted together) may be available in the aftermarket.

[Chuck S.]

Re: Really??!!...The FRONTS??...Rivets??

Uh-oh...Now I remember (and just went to confirm): flat head rivets with circular grooves in the head, in counter-bores centered between the wheel studs on the face of the assembly.

I had seen them before, but never thought about their function...you would normally just replace the entire assembly. Now that parts are becoming less readily available, other options have to be considered.

Thanks, Joe!

[Terry F.]

Re: check the runout

Strongly agree with your technique for avoiding having the rotor turned. Yes in deed you can sometimes play with the rotor postion to find the least amount of run out.

On the rear rotors, they had alignment holes. I am not sure if the fronts had them also or not??

I watched a guy use shims under a rotor Not a good idea! That was at a corvette shop in Spokane years ago. It closed down since then. That is a dangerous fix.

Terry

[Joe L.]

Re: check the runout

Terry-----

The fronts used no brake adjustment holes. That is a feature of the rears only as a result of the need to adjust the parking brakes. A new hole can be drilled in the spindle for the parking brake adjustment if the rear rotor is re-indexed on the spindle to reduce run-out.

Shimming between the rotor and the spindle is sometimes about the only way to correct runnout. If you can't get close by re-indexing (and, often you can't), then shimming might be the only alternative.

Considering the runout that can sometimes be experienced and the fact that rotors are not available in "over-thick" dimensions (as the factory used when they originally machined the rotors as an assembly with the spindle or hub), it will often require the rotors to be cut below the "discard" thickness just to eliminate the runout.

There used to be available tapered shims to correct runout. These shims covered the entire interface between the spindle and the rotor. They used to be produced and sold by Stainless Steel Brakes Corporation many years ago. These were a better approach to shimming. However, it's my understanding that due to some sort of patent dispute with the inventor of the shims (I always thought that it was SSBC founder Hans Jonas, himself, that invented them but, apparently, not), SSBC stopped manufacturing and selling them. One problem with these shims was that due to the base thickness of the shims, the rotor was displaced from it's original centerline by an amount that might result in tire rubbing if certain size tires were used on the rear.

In any event, I think that conventional shimming is ok to correct runout as long as only a small amount of shimming is necessary (like .015", or less shim pack).

[John H.]

Re: check the runout

Joe -

Those tapered circular shims are now known as "BrakeAlign" shims - see the link below.




BrakeAlign Circular Rotor Shims

[Patrick H.]

Re: check the runout

Yep. I've got a GM bulletin on how to use them to correct the runout on my Pontiac Montana minivan.

Patrick

[Terry F.]

Re: check the runout

Someone stold my idea!!

Terry

[Terry F.]

Re: check the runout

I assume you rotate them to adjust the runout. That would be a great way to correct run out. I will keep it in mind. I am sure it is a hard stainless or similar material. That would work fine.

The method I saw a guy used involved taking sheets of some type of soft material and sticking it between two blocks of wood. He would drill a hole through it for the wheel stud and then cut it out with tin snips. He would place it in two stud locations and then place the rotor over it and measure run out. The material seemed too soft and would compress over time. In the good ol days I had a friend do something like that and his wheel came off. He also had mag wheels on but there was just too much flexing going on. I blamed the shims. Not enough support under the other stud locations. Take care, Terry.