Brake Help badly needed!

rdorman · #1 (**permalink**) 12-06-2002, 08:10 AM

I have an older Unique that uses MGB front suspension, Girling 4 piston calipers and supposedly 11" rotors from a 1970 Monte Carlo. Problem is that every replacement rotor I have seen is exactly the same except that bearings are 1/4" further apart than the original rotor! This put the bearing about half on the threaded portion of the spindle!

I am trying a number of resourses but so far am coming up empty. Any one else have experience with this situation?

Thanks

Rick

Junket · #2 (**permalink**) 12-06-2002, 09:19 AM

Rick they made 2 for the Monty a one piece & 2 piece roters the early ones were the first disk like on the f85 olds67-9 chevell 67-2 later ones on GP's 7 B-special Olds 70-2 I belive on the early they used the drum spindles and later changed the spindles.Hope this makes a little $.02 mite looking at the early ones.
Ken

rdorman · #3 (**permalink**) 12-06-2002, 09:24 AM

The rotor on the car is a one peice. The new rotor is supposed to fit my car as well as the 67-72 chevelle as you made note of. Perhaps I should look at the one you mention for the Olds. Got any more information?
Thanks again

Junket · #4 (**permalink**) 12-06-2002, 09:39 AM

Rick if I remember you can interchange one way but can't the other but now it don't make sence but whats what I remember.The problen is with the spindle some how.
Ken

Cobra20646 · #5 (**permalink**) 12-07-2002, 06:13 AM

Rick,

I bought an older car too..... never had to replace rotors.... yet!

Anyway, from the book that came with my car there are several cryptic notes and the below one refers to the rotors:

Rotors, '70 Monte Carlo.
take out spacer
machine off .090" on flat side
machine off .090" off nut

I don't have a clue as to what that means, but seems that the rotors have to be machined a little to make them fit.

If you have still have the old rotors, look over them real close and see if you can find what was done to them, as you compare them with the new ones.

Let me know that you find, as one day I'll probably be in your situation.....

- Jim -

Rich · #6 (**permalink**) 12-07-2002, 06:36 AM

Rick,

Have you called Unique?

Say, as long as were talking rotors here...Last summer I noticed a clunk in the front end when I applied the brakes. Turned out that the bolt holes in the caliper were larger diameter than the bolts that held it to the rotor. Has anyone else noticed this?

Rich

rdorman · #7 (**permalink**) 12-09-2002, 07:09 AM

Thanks for the information guys.

I remember the post about machineing the spacer and nut. But that is only machineing the spacer that goes between the inside bearing and the castle nut to allow the cotter pin to slip in and to position the bearing better. This has already been done.

I talked to the Weavers and the told me the rotor IS a 1970 Monte Carlo rotor as is from Chevy, no changes required. I am working with Autospeciality (powerstop rotors) and wilwood amongst others to come up with a solution to the problem but so far no luck.

The holes in the Girling rotors ARE larger than the bolts. Some sort of bushing reamed to fit would be a good idea. Once the caliper moves forward though..... . Plus, the bolts on the OEM Jag setup are safety wired. Next time you R&R your rotors you may want to safety wire them.

For those of you running the Jag/girling set up, what size master cylinders are you using and what is your peddle ratio?

By the way, I recently changed to EBC Greenstuff pads at all four corners. Significant improvement. Seems to me they where about $180.

Search for my tip on the MG column to convert to caged needle bearings, much nicer. This winter I am changing 'sway' bar, going to tube shocks, making the camber adjustable and replacing the rubber bushings with nylon bearings. Let you know how it goes!

rdorman · #8 (**permalink**) 12-12-2002, 10:04 AM

Still looking!

bmalone · #9 (**permalink**) 12-12-2002, 10:12 AM

Rick, don't know if this is applicable to your problem, but my front-end has an assortment of different manufacturers' parts. The spindles are from a 68-71 Camaro and in order to get everything tightened down, I must deepen the grooves (can use saws-all blade or machine) on the castle nut, which lets the cotter pin line up with the hole on the spindle.

Len Hurlburt · #10 (**permalink**) 12-12-2002, 07:08 PM

Rick,

Where did the front Girling calipers come from? I have the MG front also and my front calipers look like mid-size Mopar units.

Len

rdorman · #11 (**permalink**) 12-13-2002, 11:49 AM

The castle nut has to have a little machined off the back to get the cotter pin in correctly. The problem is the bearings are too far apart in the replacement rotor. When installed, the outer bearing sits half on the smooth portion of the spindle and half on the threaded portion! Not real comfortable with that!

The Girling calipers are jaguar sedan peices. I beleive what you have is from a Dodge Aries K. The Girling calipers bolt right on but the holes in the caliper themselves are slightly larger than the bolts and should be sleaved to fit. I wouldn't give the Girling calipers much thought though. I have seen them as high as $450 a peice. I would imagine they could be had for less, never really priced them, just a casual observation. Plus they are the heaviest caliper I have ever personally picked up. Get a wilwood for a third the price and an eigth the weight!

Still looking!

Rick Parker · #12 (**permalink**) 12-14-2002, 01:46 PM

Is there enough material in the rotor where the bearing cups register to machine material and allow the bearing cups to be driven further into the bore? Just keep in mind where the centerline of the friction surface will end up after machining is complete. Maybe this will work ?????

Rick

mr bruce · #13 (**permalink**) 12-14-2002, 03:01 PM

'carlo rotors are like gold. here's your man www.ecihotrodbrakes.com ask for Ralph

rdorman · #14 (**permalink**) 12-15-2002, 12:24 PM

Rick, I looked at that posibility but there is not enough material to do the machining. The race would push all the way through. I took the rotors to a machine shop and to weld them up and machine them would be about $300!

Bruce, you are telling me they are like gold! I had the poor NAPA man pull about 30 rotors yesterday. None would work.

Where I am now is I bought a wilwood kit for a '69 camaro. I have not mocked it up yet but it still appears that the bearings will be to far apart. But, there is plently of 'meat' in their hub to move the races a bit. Obviously the adaptor for the spindle will not work so a new one will have to be made. If I get this to work I will post all the data for the other owners that have a MGB front suspension.

Any one need a nice set of 4 pot Girling calipers and EBC greenstuff pads? Bolt right on to a MGB spindle!