SM 420 cane shifter pin rebuild

My SM420 transmission has worn out shifter pins. you can see that there is a flat worn into it. Both sides have it and the groove worn into the top, which is actually the bottom, is from the retainer.

I am going to assume that they are supposed to be round and not have 2 flats where the shifter cane gets located by them

They used to go through the top of the shift tower and were riveted in place. I welded them and of course that didn't work, but did give me enough time to actually see if the transmission worked. I have had funny shifts lately. I do have GL-5 oil in there that I will be replacing, but these are both plain wore out. And the welds broke. The shifter itself does not seem to have any wear and looks to be of some sort of harder alloy .
I cut the remainder of the riveted end and weld off with a dremel.


my plan is to make new ones. I cannot rivet them, but i can make them long and drill for a small roll pin, safety wire or cotter pin on the outside of the tower where the rivet was. maybe I can even thread them. Who has done this?

 

Started to make new pins. Had some 1/2 stock.

If I was a machinist these would look better and the threads would be cut on the lathe, but I'm not there yet. I used a die. they are 10-32. The area beneath the threads is light press fit into the shift tower. You can see how worn out the old one is.

I only have 1, 10-32 lock nuts and will be going out to buy a bag from fastenal. The nuts should keep the pins in the shift tower in the absence of rivets.

 

I am going to have to deal with taht eventually.. Keep us posted..

 

Looks Great! Let is know how they work out.

 

I installed the pins.

I used vise grips to hold the pins in place while I tightened the lock nuts and marred the surface. I should have used tool steel instead of this relatively soft obtanium alloy I had laying around. They will wear and i will have to replace them eventually. I haven't driven it, but I did install the shifter. It seems to have taken out 75% of the slop. I made the pins about 10 thousandths smaller than the groove on the shifter that they ride in. Thats basically what the unworn diameter was of the original ones. All in all it was easy and effective.

 

Bravo, nice to see good work done.

 

Indeed it does! And as far as the vise grip marks go...... I always say, "it doesn't have to be perfect, it just has to be better than it was" If you repair things by that motto you will live a much happier life. haha

 

Nice work!

Those are just short roll pins on the SM465. A hose clamp around them is a cheap fix as they like to back out and make the shift sloppy.

 

Nice.. I'd say that is a vast improvement.. Now get a large run of them made and market them through Brillco.. haha..

 

Got warm enough to drive my jeep today. I filled it with GL4 oil. It shifts MUCH better. So worth the effort.

 

Good to hear. Its always so rewarding when your hard work and penny pinching pays off. fb