# Thread a gear shift stick



## sammyleach (Apr 29, 2022)

My 1989 F150 has a gear shift stick that measures 5/8. Smooth metal. I cut the end off. I want to thread it to accept a new shifter extension. What size die do I cut the threads with?
Thanks


----------



## Flyinfool (Apr 29, 2022)

If it is actually .625 Dia, not just approximatly, then use a 5/8 die. Most shift knobs you buy will have something smaller than a 5/8 thread. If you are making the shift Knob then you can make it wahatever you want. If the shifter needs to be smaller to match the Knob then you will need to remove the shifter, disassemble, and turn it down to size on a lathe.


----------



## sammyleach (Apr 29, 2022)

Flyinfool said:


> If it is actually .625 Dia, not just approximatly, then use a 5/8 die. Most shift knobs you buy will have something smaller than a 5/8 thread. If you are making the shift Knob then you can make it wahatever you want. If the shifter needs to be smaller to match the Knob then you will need to remove the shifter, disassemble, and turn it down to size on a lathe.


Thanks Flyinfool. My gauge says 15.88 mm, .6255 inches. So I need a 5/8 die? I can make the extension fit. I just want threads on it.


----------



## Flyinfool (Apr 30, 2022)

If it does not matter what thread pitch you use, I would opt for a fine thread 5/8-18UNF. Coarse thread would be 5/8-11UNC. The fine thread is easier to cut (much less material removed) and will have less slop than the coarse thread.


----------



## Provincial (May 1, 2022)

If the shaft is tapered, it will be enough larger at the base of the threads you make to cause the threading die to become too hard to turn.  For a non-precision application like this, you should carefully file off the excess material, keeping the area that he die will be threading as close to .625 round and straight as you can.  It will not take very long!


----------



## Bi11Hudson (May 1, 2022)

On most of my older trucks, the (truck type 3+1 floor) shifter had around a 1/2-5/8 shifter. The end had been cut down for 3/8-16 for an inch or so. This measurement was consistant from a '49 Chev 3800 (I think original) through an '80 something Ford F-100. It seems to be a standard size. 

If you are making your own shifter knob, the thread can be any size convenient to you. If you are using a scrounged, _or heaven forbid purchased_, knob for an older truck, or a newer foreign made Xmission, the stick must have the same thread as the knob. If a floor shifter, one plausable solution would be to drill into the shifter, tap, and use a cut off bolt. I have done that once, it was more difficult than welding but didn't set the mat on fire.

.


----------



## sammyleach (May 1, 2022)

Provincial said:


> If the shaft is tapered, it will be enough larger at the base of the threads you make to cause the threading die to become too hard to turn.  For a non-precision application like this, you should carefully file off the excess material, keeping the area that he die will be threading as close to .625 round and straight as you can.  It will not take very long!


It's straight. Thank goodness!


----------



## sammyleach (May 1, 2022)

Bi11Hudson said:


> On most of my older trucks, the (truck type 3+1 floor) shifter had around a 1/2-5/8 shifter. The end had been cut down for 3/8-16 for an inch or so. This measurement was consistant from a '49 Chev 3800 (I think original) through an '80 something Ford F-100. It seems to be a standard size.
> 
> If you are making your own shifter knob, the thread can be any size convenient to you. If you are using a scrounged, _or heaven forbid purchased_, knob for an older truck, or a newer foreign made Xmission, the stick must have the same thread as the knob. If a floor shifter, one plausable solution would be to drill into the shifter, tap, and use a cut off bolt. I have done that once, it was more difficult than welding but didn't set the mat on fire.
> 
> .


1989 F150 5-speed. Previous owner heated the shaft and melted a plastic ball on the shaft. I put a pipe wrench on it but was scared of breaking it down at the transmission. I torqued it pretty good. So I cut it off with a saw. I sent an inquiry to McMaster for a reducing thread adapter. 5/8 to 1/2 inch 13 UNC. I found a 6" extension with the 13 UNC threads. The appearance is not important cause I'm going to wrap the entire shaft with leather anyway. Still undecided on a knob. Open for suggestions on that one. Anybody here make them? Everyone here probably can but I'm not a machinist.


----------



## Jim F (May 1, 2022)

sammyleach said:


> 1989 F150 5-speed. Previous owner heated the shaft and melted a plastic ball on the shaft. I put a pipe wrench on it but was scared of breaking it down at the transmission. I torqued it pretty good. So I cut it off with a saw. I sent an inquiry to McMaster for a reducing thread adapter. 5/8 to 1/2 inch 13 UNC. I found a 6" extension with the 13 UNC threads. The appearance is not important cause I'm going to wrap the entire shaft with leather anyway. Still undecided on a knob. Open for suggestions on that one. Anybody here make them? Everyone here probably can but I'm not a machinist.


That shifter handle is tapered below the portion you cut off, unless you still some splines left.


----------



## FOMOGO (May 1, 2022)

How for are yo extending it? Don't know if you have a welder, but I would thread the extension for a shift knob, and then weld on the extension, and bled it in with a flap disc. Mike


----------

