VOIPGUY

My 59 upper outer control arm bushing holes are stripped out. My plan is to weld a bead, grind it down and re-tap the whole. Anyone know what size tap is needed?

I bought new bushings, measured the outer thread size at 15/16". Pulled out a thread guage and it looks like 10 threads per inch. So bought a 15/16-10 4 flute hand tap, welded and ground out the whole. Ran the tap through sucessfully cutting what looked like a good set of new threads, I thought I had it but.....

Problem is the bushing will not thread in, tried with lots of force and presseure but no go, so my 15/16 - 10 must be the wrong size.

Any ideas?

Don't really want to buy new A-arms yet.

Scott

Plasticman

Scott,

Can't answer your question as to thread size, but when I changed to lowered spindle supports, I found one of the upper control arm inner bushing threads was stripped. As a strictly temporary measure, I tack welded the bushing to the control arm in a couple of spots. it got me back on the road, but I replaced all the control arms a very short time afterward.

I see that the upper arms are in the $160 range, at both CC & Zip.

Good luck,
Plasticman

John McGraw

I am pretty confident that they are not Standard SAE or USS threads. The profile of the thread is completely different. My guess is that you are not going to find a tap that will do this.
I ran into this trying to clean up an ACME thread, a couple of months ago. I found that nobody makes ACME dies, that this thread can only be formed on rolling equipment.


Regards, John McGraw

VOIPGUY

Thanks John and John.

Time to bite the bullet and buy new arms.

Scott

RFJohnston

Retired tool dealer here to the rescue... ACME taps and dies can be obtained here: http://www.widell.com/

plaidside

Both my upper arm holes were over sized. I was lucky to find a complete front end from a passenger car for $250.00.
I would not try to repair them as others have said the threads are a very odd size.
With so many people relacing their front ends with modern ones I would assume there should be plenty of front end parts available.
There is one arm on ebay now for $15.00.
Joe

http://www.ebay.com/itm/Corvette-Upp...ad2998&vxp=mtr

John McGraw

Scott,

I am pretty sure that I have a couple of good ones in storage. Let me know if you need to to go dig them out.



Regards, John McGraw

VOIPGUY

Joe, good point.....was searching ebay this morn and found a few others at $35.

VOIPGUY

John, when you replaced yours did you use the arms from CC or Zip? From what at I can tell the supplier is Rare Parts Inc. http://www.rareparts.com/

Plasticman

Scott,

I received a complete used set from fellow forum member wmf62 (Bill). I had previously helped him change over his front end to a TCI rack & pinion setup, so he had no need for his original arms. His arms had been replaced previously, so they were in very good shape.

John