Transmission noise

Dave,

WOW!  That is interesting and it seems as though there is a simple solution that at worst could possibly maybe need a bit of heat.

Thank You PAS of your years of accumulated knowledge and willingness to publish it.

Keep us posted on your progress.

Peter

Unfortunately I don’t know the answer to your issue but leaving the tower off has the potential to allow the gears to float around as the shifting forks will not be holding the gears in place. I would think they would possibly end up in a bad combination which would be worse for them. Then there is also the possibility of the gears slinging 600 weight everywhere without a cover.

David

The three speed transmission from 1930 is likely to be similar to the one in my ’29 and the parts book. If so, there are four things to check before doing something drastic to the shift forks.

(1) Operate the engine while on the jack stands is to see if the same noise is there in neutral; if so, one of the ball bearings may have a problem, allowing the teeth to not mesh on their proper radial line of contact.

(2) Check the ball bottom end of the gearshift rod, it engages the pockets on the shift rails. On an old Allis Chalmers tractor I had years ago, the shift lever engagement ball was quite worn out where it refused to fully engage with the shift rails; it required significant weld build-up to make it behave. (3) Are the shifter collars on the top of each rail worn out where the gear shift ball engages?

The other area is the shift rails to the rear of the shift tower where several potential problems can exist.  (4) There is a detent ball and spring unit on the outside of each rail and a locking piece between the rails. There are three detent pockets on each rail; holding engagement into the forward, neutral and rearward position of each rail. These ball and spring units need to move freely [Is a spring broken?] and the detent pockets on the rails need to be gunk-free so the ball can engage properly to hold the gears in their proper axial engagement positions. A lock piece appears to float between the two rails to keep them separated while shifting and the ball is outside the detent pocket. If the lock does not slide freely or the ball does not seat properly into each detent pocket, the shifting will be difficult.

If the car has been sitting for a long time, some condensation may have cause some corrosion and general gunk on these parts above the oil level. If the rail does not shift all the way to the end detent pocket, the gear teeth are only partially engaged axially, which would cause some noise in each one. This inspection is pretty easy once the tower is off and does not involve operating the engine.

All these checks can be made before removing the collars and bending them; if you do pull the shift forks out, pay close attention to the wear marks on each side which should be equal, indicating even load is applied evenly on the left and right side of the fork. If wear is even, then these parts are not deformed or bent.

Best Regards,  Herb Tull