Muncie Lockup

[chuckl]

Occasionally, my M-21 Muncie will lock up in neutral and will not go into any gear. It usually happens at slow speed (or stopped), in parking lots, etc. Plus, I think it has a bit more of a whine now. It only has 350 miles on it since rebuild. It is Supercased and almost everything inside is new, including syncros (brass). The aligning slot/pin is right on. It was a bit stiff after overhaul, but seemed to work itself out to shift smooth. No leaks and no problems until the last couple of runs of 25-35 miles. I am using synthetic gear oil. Is the synthetic oil affecting the syncros? Any thoughts?

 

[chuckl]

Occasionally, my M-21 Muncie will lock up in neutral and will not go into any gear. It usually happens at slow speed (or stopped), in parking lots, etc. Plus, I think it has a bit more of a whine now. It only has 350 miles on it since rebuild. It is Supercased and almost everything inside is new, including syncros (brass). The aligning slot/pin is right on. It was a bit stiff after overhaul, but seemed to work itself out to shift smooth. No leaks and no problems until the last couple of runs of 25-35 miles. I am using synthetic gear oil. Is the synthetic oil affecting the syncros? Any thoughts?

Oops, wrong forum!!

 

[61BUBBLE348]

Did you lap in the Synchro's

 

[63impalass409]

I was told no synthetic gear oil for those.

 

[skipxt4]

My M-20 jumped out of 1st, 2nd and 3rd gear with synthetic oil in it. Take the side cover off, and make sure the springs are still on the levers.

 

[chuckl]

Did you lap in the Synchro's

I don't know if they were lapped in. Will find out. First thing is to change the fluid and see if it makes any difference. Suggested weight? Brand?Thanks.

 

[IMBVSUR?]

I have limited experience with building 4 speeds. I have torn many down, and at the time, watched and assisted building a few. The thing I always found funny was when the builder would tell the customer that it was tight, and would need some brake in, to go drive it for some time. Being that I had little experience building 4 speeds at the time ( mostly I did automatics ) I always just said nothing because I didn't own the business, and wasn't the senior or main builder. However I always wondered about the so called need for break in time because it would be tight and hard shifting. Especially when I worked with others that when built they worked fine. I guess I am just curious of others experiences after rebuilding 4 speeds, or any of the older standards. I guess I am just always concerned about "parts changers" as opposed to builders.

 

[63impalass409]

I have built many muncies and never had one that was tight and needed to be broken in like described and if built right it should ingage smoothly and easy.