Direct drum bore wear - how much is too much?

[68ElCamino]

Direct drum has ring wear in the bore caused by iron sealing rings.
How much wear is too much?
Thanks,
Joe

 

[bison]

If they are worn more than .001in deep on the outer rings I use another drum. So .002in across the diameter. The center ring gets left off 99% of trans I go through for dual feed so wesr in that area doesn't matter. Drums are still cheap and available. Verifying the drum band surface is true to the bore will reduce wear. Worn bushings and runout will cause wear to occur faster in the bushings and sealing ring areas.