Gold Lifetime Member
Join Date: Jul 2009
Location: casselberry, fl
Are these brake drums still usuable ???
I had asked in another thread if my '68 rear brake drums looked original and it was thought that they were.
Now, I am not sure if there is enough material on them to turn them and still get a reasonable amount of use out of them.
I took to them to a shop today and had the inside diameters measured. They measured 9.524" and 9.523".
A new drum would be 9.500" diameter. Looking at information from different sources, it looks like the maximum dia. they can be turned to is 9.560".....and the discard diameter is 9.590".
This would tell me I have plenty of material left but this is what is confusing me. The 1968 Chassis Service Manual says, "If a drum has to be re-bored more than .020 over the standard diameter, it should be re-bored to .060 diameter oversize and the brake facing should be replaced with .030 oversize facings."
Since my drums are already more than .020 past the standard diameter, the service manual is saying I would have to turn them to 9.560 and use oversized shoes. I'm not saying they aren't out there but I've never noticed anyone offering .030 over brake shoes.
So I'm not sure now that if I have these drums turned just enough to put a fresh surface on them, they will still be usable with the standard shoes that everyone offers.
1968, 327 210 HP, Power Steering, Power Disc Brakes, Custom Interior, 4 Speed, Console, Gauges, Tilt Wheel, Speed Warning, Fiber Optics, 10 Bolt 3.55 Posi Rear end......Owned since 1978.