Shifter adjustment, differently

[whodat]

A friend I haven't met yet reached out and asked me if I could make a shifter tip replacement (SM6) that's longer than stock so I said I'd take a look. I figured it'd be easy, a couple of round bits welded together with some flat bit in the middle. Turns out the stock shifter tip is splined, which added a whole degree of difficulty. Anyhow, there were 8 splines so I figured I'd give it a shot.

Untitled by Uncle Grr!, on Flickr

I made an attachment for my lathe a while ago that allows me to index the chuck to 60 plus 4 points, which gives me a lot of divisors. The plus 4 is what allows me to index by 8. I also made an attachment that lets me mount my cordless drill to the toolpost. This is what I did here.

Untitled by Uncle Grr!, on Flickr

This is the end result, a series of 8 holes drilled into the end of a random chunk of steel I had laying around. Note that this took multiple tries of different size drills, different diameter hole patterns, and feeds/speeds.

Untitled by Uncle Grr!, on Flickr

After turning to diameter, this is what I'm left with. Splines! If I had any of a number of other tools I could have made them differently, but that's what I had that didn't involve lots of filing or dremel tool work.

Untitled by Uncle Grr!, on Flickr

The stock part has a recess in the middle of the splines to allow the locking bolt to positively retain it. Again, other tools would have made this easier but I mounted a 1/4" end mill in my drill rig then turned the lathe on and ground the groove out.

Untitled by Uncle Grr!, on Flickr

Proof of concept part, before cleanup and deburring.

Untitled by Uncle Grr!, on Flickr

Installed in the shifter.

Untitled by Uncle Grr!, on Flickr

Then I milled a slot about a hundred thousandths deep across the center of the top.

Untitled by Uncle Grr!, on Flickr

And cut a chunk of scrap 1/8" steel down to the same size as the slot

Untitled by Uncle Grr!, on Flickr

So it fits into the slot tightly

Untitled by Uncle Grr!, on Flickr

I took an old pin that broke off one of my trailers and turned this piece out of it to size

Untitled by Uncle Grr!, on Flickr

Then drilled a matching hole in the flat bar and pressed the turned part in

Untitled by Uncle Grr!, on Flickr

The fit was tight enough that I could do a fusion weld from the back. Got a bit hot and melted the edge there, but I'm not awesome at tig welding yet.

Untitled by Uncle Grr!, on Flickr

New part next to the stock part. I'm waiting to hear how much longer than stock he wants it before I adjust it to final length and weld it solid.
Edit: I currently have from -.5 to +1.7” adjustment range. Honestly it wouldn’t be all that difficult to make it adjustable too, although I’d have to change the design and redo it all.

[Catalyst105]

You Sir, are amazing! Your part looks better than the OEM part. I’ll get you those measurements tomorrow evening. For those wondering why this is needed. I got the PB1 floorboards and the upward angle in the front leaves the space between the floorboard and the shift peg a little tight. So the point is to move the shift peg to a location to allow your shoe/boot to fit underneath, and also allow the angle of movement the lever needs to shift. Below is a stock pic of the floorboards with no shift lever, and also a close up view of mine with limited space.

https://imgur.com/IBFy59Y

https://imgur.com/1vtqq0o

97E45EE3-5E2A-47F7-A319-223F9CC911A8 by Chris Sawyer, on Flickr

[Greven]

That was indeed a sneaky way to make splines, very clever!
Nice looking result aswell, thanks for sharing!

[whodat]

Ok, so the word was an inch over stock. I adjusted the piece, welded it solid (again, fusion weld with no added filler) then sandblasted it, wire wheeled it, gave it a coat of gun blue and a coat of clear. I'll get it in the mail and see how Catalyst likes it, and make any adjustments needed at that point. First time using the gun blue on tools/parts, I like it.

Untitled by Uncle Grr!, on Flickr

Untitled by Uncle Grr!, on Flickr

[Catalyst105]

Got the shifter adjustment and it works perfectly. The splines are perfect, and allowed me to get the perfect angle/leverage, and distance for my foot to fit between the PB1 floorboards and the shifter. I have a new piece of rubber on the way. I’m keeping the OEM piece in case I need to put it back on. Thank you Whodat!