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MG MGB Technical - Speedometer Pinion

It appears that speedometer pinions (the plastic gear that goes in the transmission) are no longer available especially for the 3 sp synchros.

Any suggestions for sources? I couldn't find anything in the archives.

If your pinion goes and cannot be replaces are there alternatives? The only thing that comes to my mind is an aftermarket unit driven by pickups on the driveshaft or using the tacometer if it works.

Mine isn't bad but this thing is over 40 years old and made of plastic. A siezed speedometer or cable could wreck it easily.
Robert McCoy

It's not the sort of thing one hears about - breakage and not being able to find a replacement. I would have thought the cable would break before the gear would strip, cable breakages *are* much more common (relatively). Neither (3-sync or 4-sync) of the non-OD items seem to be available, although the ones for OD boxes show up in several of the usual suspects via Google.

A pickup on the prop-shaft would probably need two pulses per revolution to get full scale deflection on a tach. Probably easier to fit an OD if you are non-OD at the moment and get the silver lining from that particular cloud.
Paul Hunt 2

Robert-
Since it isn't damaged, fit a new speedometer cable as a precaution. Lube it up well and you should be fine.
Steve S.

Thanks guys. I plan to replace the cable and lubricate/calibrate the speedometer head this winter. That should increase chances for no problems with this non-available part.

Of course the ideal thing would be either an OD or a 5 speed conversion. With a Mk I an early OD is probably out of the question.
Robert McCoy

Robert-
Not out of the question at all. Quantum Mechanics can set you up with a three-synchro transmission with overdrive in no time. Click on this- http://www.quantumechanics.com/categories.php?op=newindex&catid=3
Steve S.

Robert, If you want a spare NON Overdrive pinion setup I can give you a set for shipping costs...
Marty Schmitz-Hertzberg

This thread was discussed between 22/12/2007 and 01/01/2008

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