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#1 Gearbox selector rod interlock

Posted: Sat Apr 24, 2021 6:51 am
by Stevedavies
Looking for the ‘interlock roller’ which sits in the end of the 1/2nd selector shaft on the gearbox. Any ideas where I can find such a part? Usual suppliers are NLA. Help would be appreciated!

#2 Re: Gearbox selector rod interlock

Posted: Sat Apr 24, 2021 7:09 am
by mgcjag
Post in our wanted section....we do get suppliers looking their regularly. ....Steve

#3 Re: Gearbox selector rod interlock

Posted: Sat Apr 24, 2021 8:00 am
by abowie
If you can give us a part number it'd help.

#4 Re: Gearbox selector rod interlock

Posted: Sat Apr 24, 2021 10:27 am
by angelw
Hello Steve,
I'll measure one and Post the dimensions. Purchase a dowel, or short length of Silver Steel rod the diameter specified and then have someone with a lathe cut and face it to length. Its a very simple parts to make and will probably be cheaper than purchasing one and then paying the typical minimum postage for such a small part.

If you don't have a friend with a lathe, cut a blank part from the dowel, or Silver Steel rod slightly over length, chuck it in an electric drill and with the part being driven by the drill, use a file to bring the part to the correct length by applying the file to the end of the spinning blank.

Regard,

Bill

#5 Re: Gearbox selector rod interlock

Posted: Sat Apr 24, 2021 7:17 pm
by Stevedavies
Bill, that’s very helpful. I have the old one but it’s badly worn and not sure I can get a meaningful measurement from it. What you suggest would certainly do the job and could be easily tested by reassembling the lid.

Thanks again

Fyi the part number is listed as no 207644 on the SC parts website

Regards
Steve

#6 Re: Gearbox selector rod interlock

Posted: Sat Apr 24, 2021 7:19 pm
by Stevedavies
Andrew SC parts show the interlock roller as 207644

#7 Re: Gearbox selector rod interlock

Posted: Sat Apr 24, 2021 7:28 pm
by steve3.8
Steve , i think the part you need is C20066 ?-- with Bill's help it would be easy to make one . If you do struggle though , a guy on ebay 'morsejags' will more than likely have one.

#8 Re: Gearbox selector rod interlock

Posted: Sat Apr 24, 2021 8:02 pm
by Stevedavies
Cheers Steve. I think Bills suggestion is a great one. Knowing the dimensions would give me a good shot at making one. My part is badly worn. It does look like there are indents ie concave ends to the pin (assume to seat the ball bearings either end of the pin. It’s either that or the ends are also badly worn!

#9 Re: Gearbox selector rod interlock

Posted: Sat Apr 24, 2021 9:14 pm
by abowie
Stevedavies wrote:
Sat Apr 24, 2021 8:02 pm
Cheers Steve. I think Bills suggestion is a great one.
I agree. Use silver steel as he suggests and heat treat after ensuring it fits.

It does look like the ends need a cup to hold the ball bearings in place.

#10 Re: Gearbox selector rod interlock

Posted: Sun Apr 25, 2021 7:51 am
by angelw
Steve Wrote:
Knowing the dimensions would give me a good shot at making one. My part is badly worn. It does look like there are indents ie concave ends to the pin (assume to seat the ball bearings either end of the pin. It’s either that or the ends are also badly worn!
Hello Steve,
The roller is 9/16" long. There are no concave ends in the four I looked at today and none were hard. However, there would be nothing wrong with hardening the roller once you have the machining to length completed. Therefore, I would use Silver Steel Rod, as its finish ground on the OD and its will harden easily.

Heat to a cherry red then quench in oil. Polish the OD with scotch bright so that you can see colour change, heat again but only to a very light straw colour and quench in water. This will temper the steel so that its not glass hard.

Regards,

Bill

#11 Re: Gearbox selector rod interlock

Posted: Sun Apr 25, 2021 2:33 pm
by Stevedavies
Bill, that’s very helpful. I can see the ends are concave on mine but may well be wear I am seeing.

Do you have the diameter of the pin?

Regards

Steve