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Thread size on Fulcrum Pin

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kurts100

kurts100

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OK. I'm stumped. Trying to clean out the bushing treads on the A-Arm (Wishbone arm) on a '59 Bugeye. The small hole measures out to 9/16" x 16, which is British Standard Fine thread, but the large measures 5/8" x 16 and I can't find a tap that size anywhere (BSF, BSW, etc.) Was this just some oddball thread size they used in these bushes and fulcrum pins, or am I missing something.

Thanks!

Kurt
 
IIRC, It is an oddball size.
 
But, isn't it big enough to get a small (dremel sized) wire wheel in there? likely easier and quicker at this point than to find a one off chase
 
Thanks Guys! It must be oddball size. I rechecked threads per inch and they are 16. When checking 11/16" on the chart, it would have 14 tpi if BSF. Think I will try the very small wire brush on a dremel. My buddy has one.

This has been a royal pain getting the fulcrum pin out. Ended up cutting it with a cutting wheel right next to king pin. Was able to get large end out but had to take A-Arm to machine shop to mill out the small end. We figured when doing that it would just spin out, but of course it didn't. He took it down to just above the threads in the bushing and now I'm hoping I can take the 9/16" x 16 tap and re-tap. Luckily the large bush with the oddball thread just needs cleaned up and I think the wire brush will work.

Thanks again for input!

Kurt
 
No matter what the diameter of the larger side is (it is 5/8") it HAS to be the same pitch (threads per inch) as the other side, otherwise it would bind up when you first insert it and never go fully in.
BillM
 
You can actually buy the brazed-in inserts with that thread (the ones fitted to the A-arms).

I know they are available via the "spares scheme" at the Austin A30-A35 Owners Club.

I forget the contact info for the fellow in charge of their spares. His name is Stan Chatterton. You can find him on ~their forum~.
 
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