View Full Version : Thread adapter
JohnCh
12-09-2006, 03:22 PM
I have a new gear lever that is threaded to take an M10x1.5 shift knob. Unfortunately my existing shift knob is threaded for my old M12x1.75 lever. Any ideas where I could get an adapter? I was thinking that perhaps a Time-Sert/Big-Cert or HeliCoil might work, but I've been having trouble finding the outer thread size of the M10x1.5 versions.
Thanks,
John
slomove
12-09-2006, 04:28 PM
Hmm, not sure if I understand...you are looking for helicoils that can be used on a 10x1.5 shift lever? I have some left over from a project where I made some turned wood knobs for myself and some other fellows. But they were not difficult to find, I believe even at PepBoys autostore. If that is all you need and can not find it locally I can mail you a few. Would to have to lend you the tap and inserting tool, too. Let me know!
Gert
http://home.earthlink.net/~slomove/sitebuildercontent/sitebuilderpictures/woodshiftknob.jpg
JohnCh
12-09-2006, 08:52 PM
Gert,
Thanks for the offer. I guess in my attempt at brevity though, I took a detour at clarity. Therefore, I'll bore everyone with the complete story http://www.usa7s.com/aspnetforum/images/emoticons/wink5.gif
Several years ago I upgraded the gear lever on my Westfield to a Quaife Quick Shift. Unlike the Westfield factory gear lever which has M10x1.5 threads for the shift knob, the Quaife features a beefier shaft with M12x1.75 threads. When I bought that new lever, I purchased a Team Voodoo shift knob and matching handbrake grip. I then had the shift knob laser engraved with the Westfield logo.
I recently purchased a gearbox from BGH along with their gear lever extension for Westfields. It is a sturdier design than the Westfield factory extension and requires the use of the modified gear lever they supply. Like the stock Westfield gear lever, it too requires a shift knob threaded for M10x1.5. Unfortunately Team Voodoo doesn't offer a shift knob with that thread size.
So I am trying to find some kind of bushing that will enable me to screw my M12x1.75 threaded shift knob onto my new M10x1.5 gear lever. I thought that a Time-Sert or HeliCoil for an M10x1.5 bolt might work, but before I buy either of those I want to find out what size hole (diameter & thread pitch) they require. I'd hate to buy one only to find out that the M12 hole is still too big.
If I can't find an off the shelf solution, then I need to find a machine shop with reasonable rates. (yeah, like that is going to happen http://www.usa7s.com/aspnetforum/images/emoticons/wink5.gif ).
-John
slomove
12-09-2006, 10:04 PM
The 10x1.5 helicoils I used have an outer diameter of 12.25 mm. I guess that should work. A machined adapter may not be feasible because there is no wall left with 12mm outer and 10mm inner thread.
I guess the easiest solution would be either
- to re-tap your threads with the helicoil tap and just live with the cross-threaded result (probably still ample strong)
- to ream out the knob thread to 1/2" and insert the helicoil with epoxy glue using the insertion tool or a 10mm bolt (wrapped with teflon tape for removal).
- combination of both above, i.e. re-tap and seat the helicoil with epoxy. That is what I did for above mentioned wood shift knobs.
Gert
JohnCh
12-09-2006, 10:40 PM
The 10x1.5 helicoils I used have an outer diameter of 12.25 mm.
Thanks Gert! I'll pick up a HeliCoil kit and do the retap and epoxy as you suggest.
-John
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