The Stovebolt Site Forums The Shop Area Driveline SM420 shift tower pin question

So, what is the distance of the retaining pins in the shift tower that secure the shift lever of a SM420? What I mean is how far do the pins extend into the tower as well as outside of the tower? Thanks.

IIRC, only the rounded heads of the pins extend outside of the shift tower. Kinda like the head of a rivet. Otherwise pretty much sits flush with the outer sides. The pins sticking out on the inside is about 1/8" (or around that) from the inner wall to the end of the pin. Only has to be long enough to engage with the slots in the shift collar.

Thanks for the info. Looks like some type of roll pins were put in. One sticks out about 1 or 2” so I can’t get the trans cover over it. Can I get the pins as replacements?

Snowman, After having a little more time to dive into this subject, I would suggest reading through this entire older thread on the subject. Many folks chimed in with great possible fixes for your dilemma, as well as how to remove the old pins and such. Big Hint - The GM# 590282 original part number for replacement pins posted back in 2018 is still valid and there are even several folks offering them, mostly on evilbay. After reading through this, pick your poison on choice of repairs and happy shifting!

Thanks Gdads51. As always, appreciate the advice. Will be tackling the project soon. Lots of fine weather left for driving the ‘51.

I have threaded the shift tower holes and used 5/16-18 dog point setscrews instead of the pivot pins. Adjust them in or out for the best fit, and use red loctite to maintain their position. Grind the tip back a thread or two to lengthen the engagement if needed. It's a simple permanent fix.

www.ebay.com/itm/193260086856?

Jerry