Muncie M-20 Speedo question

[jackfit]

Hi ,

Just when you think you done, you're not. As I try to finish all mechanical work on my 66 , prior to paint, I have decided to tackle the speedometer problem again. Rebuilt my dash speedo, and put in new driven gear (22 teeth) and fitting for 3.70 rear. Tranny is M-20 wide ratio, original to car along with motor.

I had speedometer working for first time in years..... for 90 miles !!!!

Dash speedo works........Driven gear chewed up at transmission fitting.

L79 M-20 and original rear was 3.36 Changed rear 35 years ago to 3.70

Question

Does the speedo drive gear on the tranny shaft have to be changed to be right for the 3.70 rear end or is the one on it OK for 3.36 and 3.70

Also, the spot where the driven gear (plastic) rests on the transmission housing is excessively worn. The plastic gear has vertical motion in fitting more than I think you should.

Can this be part of problem?

I was on my back all day to take out tranny,, Boy, a lift would really make that job easier. I only want to put this car back together once , before my trip this summer.

Comments on possible fixes please........

Jack

 

[jackfit]

Hi, update on Speedo gears and leak

I put the transmission in this morning, putting a tranny in a car on jack stands has to be the all time job from hell. 3 hours later, tranny in, mufflers in and all that other stuff that was in the way.

12* outside, sunny, no top, interior out for paint,

I took her out.

1 hour later, speedometer within 2 miles of gps.
3 hours later no leaks on floor

It seems that the new drive gear, plus the silver 22 , plus a good transmission man, Laurence Stiles retired, knew what to do and he did it at a very reasonable price.

It was great after so many years of not having a speedometer to work, to see it move and hold speed. Car is now all done and ready for paint in about 2 weeks.

Thanks you all for your help, hope to see some of you this summer / fall

Jack