where the shift knob attaches to a Rennshift shifter there is a hole drilled and tapped. What size bolt is it tapped for.

Bolt size?
Bolt pitch?
Bolt length?

Thanks!

Zach

No bolt needed. Most knobs fit over the shaft and use a retainer screw or two. Remember the aluminum one I gave you?

For my current project, it would be much easier to mount a piece of aluminum all thread with the correct pitch then to try and make a round knob with with a crush ring or retainer screws.

*edit* I just ran oout to the garage and grabbed that aluminum knob you gave me. I could not feel it in my hand when I got back in the house. That f*cker was COLD!
Zach

I *could* get a piece of aluminum tube. I found the right stuff at McMaster Carr. But a bolt will cost $1, and the tube will cost $25 plus set screws and a tap (lets say another $25.) I can make ~ 11 knobs with the smallest tube shown, so that would be $4.5 per knob.

However, there would be weight savings, as there would be less wood.

hrm....

Zach

Aluminum round stock, center drilled and tapped, get a machinist to knurl the outside, ( or sit down with a case of beer and a file and cut cross hatching in it yourself ) insert this internally threaded insert into your new wooden knob ( pre- drilled ) with a coating of Gorilla glue to hold it in place.

okay, there are 2 ways to do this.
Click to view attachment

Way 1.
3/4 inch OD, 5/8 inch ID, 1 inch long Aluminum tube mounted in the shift knob. Shifter arm goes into tube, and is held in place with a set screw.

Way 2.
Aluminum all thread bolt goes into knob and glued into place. Knob simply screws into threaded shifter arm. Knob will sit 1.125 inches higher then way 1.

Either way will lend strength to the knob and should sit secure on the shifter arm.

Way 2 seems like it would be easier, and I know it would be cheaper. Is there a reason why I should not do it? The shifter arm must be threaded for a reason, right?

Zach

I personally do not like set screws UNLESS the item they are being attatched to has a countersink for the screw to go into. Set screws on a level surface tend to not hold their place. I would go with no. 2 myself.

Not to mention, a set screw in the wall of a hunk of aluminum tubing isn't going to be set for long...

Have you tried to go to Jwest' site? How about PMing James?

I put a note in to him on his site. Sometimes asking here is faster.

Zach

OKay, I went to True Value this afternoon and found the answer.
For anyone that is interested in following in my footsteps:

Threading is:
3/8inch
24 TPI (fine)
~1 inch deep.

I picked up a 3/8 inch aluminum rod, and a die.

Zach