Suggestion for thread repair

BigDanT

Member

I have a 641 with the HD front end. It takes the threaded axel pin as shown. I was able to purchase a new pin but as my luck would have it the female threads inside the bolster are badly worn. It will somewhat thread into the bolster but when torque is applied the threads let loose. It is a 1.75"x16 thread size pin. The service manual calls for 200lbs of torque to the pin. Building it up and re-tapping was my first thought but I have been unable to find a tap that size. Any suggestions on how to remedy this situation?
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Put it together, tighten it up as best you can then weld a couple of good tacks on it.
If it ever needs to come off again you can just grind the tacks off and take it out again.
 
Thanks UD, but I'm not so much worried about the pin coming out. There is a retaining plate that will capture the hex head and shoulder of the pin not allowing it to back out. The thing is with this front end, to minimize wear you gotta torque that pin to lock in the bushing. It more or less squeezes it in place. That being said, you have given me an idea...why couldn't I clamp the bolster and tack the bushing in place? Would serve the same purpose, I would just have to grind the tacks if I ever had to remove the axel. Thx
Dan
 
Clamp the bolster and weld the pin in. You?ll never get the bushing to stay by welding it. Use the welded pin as a clamp just as it was when the threads were good.
 
RickB...could it be you?re thinking of a standard bushing? This one has 1/4? side walls making it plenty thick enough to hold the bolster,actually much thicker than the pin.
 
I?m thinking of the physics involved. Your way the weld is in tension, my way it is in compression. Way less chance of failure welding the end of the pin to the bolster, especially if you ?tack? the bushing.
 
I had a lathe man make a nut that i put on the engine side. Its still there but I cant remember if we removed that inner steel plate on the bolster.
 
Any suggestions on how to remedy this situation?

You may have settled on a solution but I was wondering if you could you use a longer grade 8 bolt through the center of the kingpin to secure it in place or is it a solid pin?
 
The pin is hollow, I just measured and it looks like I could use up to a 1 1/4" bolt through the center. I'd have a to get creative with some shimming on the back side but it is doable. Making a nut is also possible but I think it would definitely need the plate removed on the engine side (no exposed threads as is). Both great ideas. Thanks
 

I have this extra bolster that was on a parts tractor that I picked up. I would like to get it in good shape so it is usable, but the pin threads are a little out of shape. My question is? Someone posted a link to someone that made the part for them, I thought I bookmark
it but I can't find it. Anyone know? This is on a 64 4130.
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It looks like the bolster is spot welded to the support or at least spot welded and then oven fused/brazed later.

How difficult would it be to remove the adapter and put a new one on in?
 
Yea they are very much alike. Can?t tell for sure but
they even look to have the same thread size. That
in of itself creates a problem...couldn?t find a tap to
match. Doubt if that piece is replaceable with
something off the shelf.
 

I weld them in I have even used a 8N pin it fits the threaded part real nice and snug then welded it in... The best option is a good used part...
 
There are 1-3/4-16 " taps available, but the cheapest for a new one is at least $75. There are some taps that say 1-3/4 x 16" , but they are only 3/4".
 

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