I finally pulled that tunnel up and had a look at my T-18. The shifter was tremendously sloppy, and it was so hard to find the gears that I never actually did hit 4th the day I drove the truck home.

Someone had already bored out the hole and probably the slot for an oversize pin, and the pin was plainly shop made. Either the last guy ground some weird angles onto the pin, or it wore in a very peculiar way. It was really bad!

After mulling over my options, I decided not to bore or widen or true anything at all. Instead, I took a drill bit that was way oversized, and I machined it down so that it fit right into the slop. Here is an exaggerated artist's rendering of the form the pin took:



It has to be inserted from the inside, so I had to be extremely careful not to drop it into the transmission. The taper matches the wallowed out hole, and it's a close enough fit the pin has to be tapped out. On the other end, instead of a round pin, I went with a squared off surface whose angles match the wallowed out shift ball on the stick.

I fooled with this thing back and forth to the grinder again and again until I had a fit that really makes me proud. It's loose enough to function, but only just. This stick is as crisp and precise as I've ever shifted. Best of all, all it cost me was a drill bit in a weird size I'll probably never miss anyway.

 

Good work.
I'll take one.

I converted my T18 to M5OD because of the slop in the shifter and the ratios.

Can you describe this. I can't ever remember my T18 being smooth. My dad swapped from 3 on the tree to the T18. We would sit in the middle and change gears when I was younger. I drove it all through high school and remember it always being sloppy.

I tried to put it on craigslist last year but didn't have any takers. Not a very modern transmission for daily driving.

 

Pull it over and up against the dash, first. Tug back gently, second. That part worked fine with the sloppy shifter, once you figured out where to hold it to take up most of the slack.

Then over to third. Where is third? Uh oh, that Mercedes is coming up fast. Where is third?! There it is! Whew!

Then it's time for fourth. Traffic is flying all around me, and that Mercedes is offended by my existence. Please let me find fourth gear so I don't have to get snob cooties all over my truck! GRRRRRRRRING!!!!! Nope, reverse! GRRRRRR! Nope, second, GRRRRRRRRRRING!!!! Reverse again! Stick it back in third, wind it up again, feel around, it should be there..... there...... almost in..... almost in........... FOURTH!!!! YEAAAAH!!! Annnnnnnd.... Now the light is red.

After my surgery, 3rd and 4th work just as well as 1st and 2nd. You just slide it over where it should go, and bang, there's 3rd. You pull back gently and uneventfully, and 4th is just another gear.

Basically it shifts like a normal transmission now. It's amazing what a little piece of metal maybe 1/2" long can do.