How to disassemble the spring loaded knobs on the South Bend 9A?

Domodude17 · Sep 13, 2017

I don't know what they're technically called, but I am referring to the spring loaded plunger knobs that control the quick change gear box, as well as the drive selector knob on the apron that selects between half nut feed, power feed, and power crossfeed. The handle portion of mine are quite rusty and it would be nice to take them apart for cleaning and polishing, but I haven't found anything on how to do so. Is it generally ill-advised to do so, or is it straight up not possible? Thanks!

iwananew10K · Sep 13, 2017

You can do it but unless there is a problem IMO it not worth it because it's a PITA.

but if you must...look for posts from FTFengineering on the subject.

tobnpr · Sep 13, 2017

True that.
Been a couple of years since my resto, but I remember looking into it at the time and said hell noooooo....just finding the taper pins was a job in itself IIRC.
But, mine weren't that bad.

lsneon · Sep 14, 2017

My 9A (1945) was not too bad. Made a couple punches, one 3/8 T6 and the other
3/8 brass. With these you can get the pin to move without damaging the knob then
change over to the correct pin driver. Guessing with a steel driver is gonna leave
an ugly spot. Just a note, my pins were NOT tapered.
Backed the knob up with a piece of oak on top of a large piece of steel then
kinda best guessed as to where the pin was. On most you can get a fairly good
idea by cleaning very well and then using a strong magnifier. Some folks were
able to look in the hole in the end to determine pin orientation. Good luck and
stay safe.
lsneon

Domodude17 · Sep 14, 2017

Ah, I didn't know there were cross pins. They do blend them in pretty well! I managed to find them, but yeah, it does look like a gigantic pain in the ass. I think i'll pass!

comstockfriend · Sep 14, 2017

This comes up all the time. Unless the springs are rusted in there, I'd leave them alone...

Another thread on the same topic:

http://www.practicalmachinist.com/v...ving-spring-loaded-pin-reversing-gear-338613/

Yan Wo · Sep 15, 2017

I couldn't bear to not disassemble mine. The pins were not that difficult to drive out. Mine were not tapered, so finding the small end is unnecessary. I replaced the pins with stainless set screws.

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How to disassemble the spring loaded knobs on the South Bend 9A?

Domodude17

Aluminum

iwananew10K

Diamond

tobnpr

Hot Rolled

lsneon

Aluminum

Domodude17

Aluminum

comstockfriend

Hot Rolled

Yan Wo

Stainless

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