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TR2/3/3A TR3A Brakes

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N

newguy

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Can any body assist me with the minimum safe thickness of the front rotors. I don't think it matters but if needed the comm.number is TS76775L. Need to know if I can turn them or if it's time to replace. Thanks in advance.
 
The only thing I can find is in the Haynes Manual and it says "Under no circumstances should more than .060" be removed." Don't know if this helps or not, Somebody else may have some more definitive information.

Welcome to the forum!

Cheers, Tinkerman
 
The manual only says that a maximum of .060" should be removed -- without saying what the original thickness dimension is.

I think someone else around here might have that info.
 
The original thickness of the 10" diameter rotors that came new on my early 1958 TR3A were 0.500" thick. In 1990, I had 0.002" to 0.003" skimmed off each side of each rotor to remove the surface rust, scratches, etc. and I have driven 103,000 miles with no issues since then with the thickness of each rotor at 0.495". They are still like new. It's nice to have a neighbour who is equipped with a 10" lathe.

Note that the thickness spec. might be different for the 9.75" diameter rotors they started using and still supply right up to the TR6.

Ask a TR6 rotor supplier.
 
Uh, Don, I think if you'll check, those were 11" rotors. But I agree about the .500" part (making minimum acceptable about .440"; although I have seen people run them much thinner with no apparent problems).

At least some of the later 10-3/4" rotors are stamped .440 minimum; and new ones also measure very close to .500".

BTW, the new rotors I got from Rimmers a few years back (at a show) have some significant balance issues. If you are replacing rotors, you might want to check the balance afterwards, as well as the runout.

Are your old rotors scored or something? While common practice these days is to resurface them at every pad change, it seems like a waste of very expensive metal to me.
 
I was getting a tremendous amount of noise from the front brakes. I tried scuffing the pads a little and it helped for a few miles. When the noise came back, I thought it was time to take a good look. The rotors looked good but I thought I would just touch them with the turning lathe at the same time I was installing new pads. I appreciate everyone's help. The finished rotor thickness was .465 on the passenger side and .460 on the driver side. I am bedding them in now and everything seems great. Thanks again.
 
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