Brake Drum Substitutions

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Ivan D Bagski
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Location: Meadow Vista, CA
Model: 2000
Year: High Windshield-68-70

Brake Drum Substitutions

Post by Ivan D Bagski »

The machine shop I took my finned aluminum drums to says they can't be turned anymore. Foolishly, I forgot to ask him what they measured out at, but assuming I need to replace them on my '69 2000, and assuming I don't want to pay $600 for new aftermarket drums, what alternatives are there? I understand that 240Z drums will fit with some modification, and I've seen the drawing for the modification, but I don't understand just what that drawing is showing, and I don't see any further explanation of how you adapt the 240Z drums to a 311.

Can someone clarify my options?

And by the way, what is the maximum diameter the drums can be turned to? Or is there a minimum thickness? Some other spec?

Thank you.
DAC21
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Re: Brake Drum Substitutions

Post by DAC21 »

The wear limit is 9.055 inches per this thread. I know I don't have calipers that will do 9+ inches.

viewtopic.php?t=4472

It is mentioned by one 311s member that it is possible to have the rear brake shoes relined with slightly thicker linings to compensate for drums that can't be turned again. I believe to use 240z drums the outside lip on the Roadster backing plate needs to be bent vertical. There may be more to it than that, especially on 1967 and earlier cars. Run a Google search for 240z drums on a Datsun Roadster and threads will come up with additional info.
Last edited by DAC21 on Tue Oct 19, 2021 5:23 am, edited 4 times in total.
1967 1600 in waiting SPL311-09002 / R-28178
2018 Hyundai Elantra GT Sport Ultimate
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redroadster
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Re: Brake Drum Substitutions

Post by redroadster »

Unless the drum has been severly turned ,,,it's ok , on thickness , these are nearly golf carts
But for legal reasons the shop has to go by the specs
With unpowered brakes you're not going to cause it to fail
todd lorber
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Re: Brake Drum Substitutions

Post by todd lorber »

You might look into a service like this:
https://www.jgrelining.com/
I've never used them but it looks like this is not uncharted territory.
unklpat
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Re: Brake Drum Substitutions

Post by unklpat »

I have a pair freshly turned. $100 plus shipping Pat