View Full Version : TR2/3/3A TR3 brake rotor question

05-30-2012, 05:31 PM
I just bought new after market calipers and found that they won't fit on my 11" disks. The correct caliper is not available, so Can I install new 10 3/4" rotors without modifying anything else?


05-30-2012, 07:25 PM
Moss sell a 10.75" rotor that is drilled, part no. 586615. Others may have better information, but I understood that the rotors and hubs are similar or identical from TR2 to TR6, so you should not have a problem. I assume that it is only the diameter that is a problem and not the thickness or offset of your after market calliper. Goodparts sell a lightweight rotor with a separate hat which is 10.75" but it is a lot dearer. Depends on your budget!

05-30-2012, 08:37 PM
You may want to check also if the caliper mounting brackets are compatible - it might be worth pulling the 11" rotor and making sure your new calipers bolt up correctly. I think they might, but with the popular Toyota caliper conversion I'm pretty sure they talk about using later mounting brackets for the earlier TR3 cars.

05-30-2012, 09:44 PM
The hub is the same, but I agree with Randy, I think the caliper mounting bracket is different.

Also, those early calipers are more or less infinitely rebuildable. Everything that wears is replaceable. TRF will sell you rebuilt early calipers (likely Moss will too but I didn't check).

Yet another thing to check is the diameter of the mounting holes in your new calipers. I forget the change point offhand, but the holes got bigger at some point in TR6 production. Since it is important that the bolts fit snugly in the holes, there were $pecial bolt$ with oversize shanks to use with the later calipers.

05-31-2012, 07:08 AM
The change was in '72 at CC81079 (according to Moss). They went to a 12mm shank while retaining the 7/16" threaded section. They are necessary when going to the Toyota caliper conversion if you have an earlier TR. Also, you'll need the late TR4/TR6 brackets if your putting them on a TR3 or early TR4...I don't know what the break off point was on that issue.

Edit: Also, if everything else is all right, why not just get a brake place or machine shop to cut the rotors down. We're only talking an 1/8" on the radius.