1982 rear rotor

[jimbil208]

I have a broken lug stud and am attempting to remove the rotor.

I have the caliper off and if I am reading the book right, it tells me to

drill out the heads of the rivets and I don't have to replace them as

the lug nuts will hold everything together.

Anyone do this before?????

Do they mean the large rivets that are staggered between the studs for the

lug nuts?

Thanks, Jim

 

[bill81vette]

they are riveted to keep the calpier true,in other words,it wouldn't warp,hence causing
the calipers to introduce air into the system.a lot of the calipers have been rebuilt with o rings
instead of the original lip-seals which were suck a headache and had air introduced
into them and made the brakes spongy and not work properly.

 

[GTR1999]

Jim
The rotors were riveted to the spindles and front hubs then turned as an assembly to produce -0- runout. This worked great until someone removed the rotor to replace or face on a brake lathe. When the new or refaced rotor was installed, usually runout wasn't checked, and brake problems developed. Been like this since 1965 with a lot of people not understanding the system and what may happen with it. I have run stock lip seal calipers for 35 years without issue as long as the runout is under 003" and the bearing endplay is setup between 0015-002". If the car is put in storage for 3-6 months the brake fluid should be replaced when you pull the car out.

For replacing your rear stud you should be able to pull it in with some lug nuts,the rotor should be removed. Mark the position so it goes back on in the same orientation. Center punch the rivet head, center drill it, 1/4" drill about 1/4 deep, then 5/16 same depth, this should put the hole deep enough to be past the thickness of the rotor head, then use a cold chisel across the rivet face to split it and it will come out. When all the rivets are out, be sure the parking brake shoes are collapsed and the rotor should come off. The rivet bodies will still be in the spindle flange so you can either drive them out or just grind them down flat to the flange. I wouldn't hammer too much on the spindle, when ever you rebuild the T/A then the rivets can be removed. When I rebult T/A's I tap those holes and bolt on the rotors to dial them in. Take a 2" emery wheel on a 90* die grinder and dress the area around the holes on the spindle and the inside of the rotor hat. Replace the stud and be sure to check the rotor runout when you install it, before you install the caliper. Over 005" you should address it. Under 005 or as mentioned under 003" is what you want. Deglaze the rotor face with a 100 grit D/A and wipe it down with brake cleaner.

Gary

 

[Vettehead Mikey]

Gary's got it right. The rivets were for manufacturing convenience only and serve no purpose beyond that. Just make sure that the rotor is reinstalled in the orignal position and you'll be fine.

 

[Hib Halverson]

Gary's got it right. The rivets were for manufacturing convenience only and serve no purpose beyond that. Just make sure that the rotor is reinstalled in the original position and you'll be fine.

Well....I'm not sure sure that's all correct. It's true that riveting the rotors to the axles then machining that as an assembly was a manufacturing "short cut" getting GM out of having to make both rotors and axles which ran "true" but, once you drill out those rivets, you must keep the rotor indexed to the axle the same way as before because there is a chance that the axle flange is not perpendicular to the centerline of the axle and there's a chance that the rotor's friction surfaces (some call these "brake plates") are not parallel to the rotor's axle mounting face.

Those rivets served two purposes: the first, admittedly not that important, they held the rotor to the axle during mfg. and the second, real important, they indexed the rotor to the axle in the position with minimal runout.

So...before you drill the rivets out, mark the rotor such that, after you replace the wheel stud, you can get the rotor back on in the same orientation it came off.

Lastly, considering the age of the vehicle and that one stud has broken already, I'd replace all five not just the broken one.

 

[jimbil208]

I thank everyone very much..................

Jim Now back to work.

 

[GTR1999]

I will add I never install vette rotors without bolting them on and dialing them I never like retaining them with just the lug nuts. Yes it takes longer to do but once the rotor is dialed and bolted on you're done, just like with the factory setup only you can remove it if need be. Some rebuilders have been advising indexing the rotors to get the best spot for minimal runout but this covers up the rear adjusting holes. To each his own I suppose, just be sure you dress the parts as the surfaces will be raised slightly once the rivets are removed.

 

[jimbil208]

Thank You, Gary