rev counter sending unit for md7a tachometer, 1979

[darrell randolph]

here is a question i could use this boards collective wisdom on. i have been looking for a replacement sending unit with no luck. seems that this part is no longer made.
i have found a very similar unit (same mfg. VDO) and the electric supply house said it will work if i can get it into my engine housing. the threads are very close to fitting (within 1/32 to 1/16 of an inch too big). i am considering filing the threads down as much as needed to get the unit into the hole, and then securing it there with some sort of epoxy or jb weld material. i dont plan to put the epoxy into the hole, but rather on the housing surface, and on a lock nut that is on the unit to hold it in place.

what problems do you see with doing this, if any? will the epoxy hold up to heat from the engine?

thanks in advance for your thoughts
darrell randolph
mystic rose, cd30k

[Dwain Douglas]

You might consider using a 'die thread cutter' to cut the threads on top of the old ones. It would not be pretty but it would probably work fine since there is little stress. A machine shop could do this. On my '83 MD7B the thread is M18 x 1.5

Dwain
CD 30 for sale http://www.dwaindouglas.com/