New Read Brake Drum Splines Not Centered?

[Jim Dangerous]

Bought a brand new pair of Zimmerman rear brake drums for the bug, upon closer inspection it seems the central splined hole is slightly off center (see pic) there appears to be more material on the left side of the hole than the right side, how worried should I be? Anyway to check it with DIY tooling? Or just put it on the axle and spin it? Unfortunately it's harder to see the issue in the provided pic, it is much more noticeable in real life! Turning the drum over, it looks perfectly centered from the other side.

Note: Both of the new drums seem to have the same anomaly!

Many Thanks,
Jim Dangerous

[Eric&Barb]

Brake drums for the VWs at least are cast. So the outside (Other than the surface the rims attach to) is not a worry, and so was not machined completely to perfection to keep down labor cost per drum. It is the splined hole in relation to the surface the brake shoes contact to is of vital importance.
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In Stereo, Where Available!

[Cusser]

My 1970 has "Raybestos" premium rear brake shoes purchased through RockAuto; neither stated Raybestos but both were stamped "made in Germany".

I never paid any attention to whether they were out of round or not, they've been fine. Maybe I'm a realist and not a perfectionist.

But at least I can bleed VW brakes properly !!!!
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1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[scrivyscriv]

If the splines were machined off center of the drum ID, you will see uneven contact when you adjust the shoes. Without a lathe and dial indicator on hand, I’d just install them and make sure they spin 360° without binding once the shoes are adjusted.
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Robert in Memphis
Dünkelgrügen 1967 Java Green bug thread
Engine rebuild thread
If you're ever in the Memphis area, you are welcome to stop by for advice and help.

[bsairhead]

All machining would be done off of the center point.

[Jim Dangerous]

Thanks for the replies, I've fitted the drums onto the rear axles with new shoes. Both drums have an area where the shoes rub and drag slightly during rotation of the drum, but not enough to bind completely, so i'm guessing that is ok and will wear in eventually? Or should and drag be consistent over the full 360 degrees of rotation?

[Eric&Barb]

[my3bugs]

untill you drive it n really step on the brakes is it really centered ? but ya when i rotate the wheel with a fresh set of shoes there is always one spot that touches more that the rest as your adjusting em .............after a full new shoe adjustment i hear more than that . if not adjusted pretty snug you will be doing it again real soon as they wear or break in wearing off those high spots .

[Cusser]

With new brake drums and/or new brake shoes, I find one needs to manually adjust the brakes several times as the brake shoe linings wear. In the "old days" the new brake shoes were ground to match the arc, but that got dangerous particles in the air.
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1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[my3bugs]

long long ago in my youth i used to get my drums turned just cuz that FLAP parts store said so . i doubt they really needed to be turned unless you went thru the pads/shoes and went metal to metal ......... but i have had that happen in my youth ..........now days i put new shoes on long before that ever happens and i been riding these drums a long long time now ............ i have a box full of semi used shoes , shoes are cheap !!!

i might have read that in the idiot book ........ dont turn a good original VW drum unless you really have to ??? not just cuz you want a brake job .

[Eric&Barb]

[Cusser]