VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 1937 three speed jumps out of gear

I have been asked to fix a gearbox, It was hard to get into second and would jump out of that gear.
I've pulled it apart , and another 3 g/boxes and everything is worn.
I find it hard to tell what actually causes this defect as I have no new parts to measure.
For example , what end float should there be on the main shaft?
How thick for the 2nd gear thrust washer?
Who might have new syncro hub / gears etc?
What else might cause it to come out of gear?

Thanks for your thoughts.

Shifter forks, syncro. drum, energizer springs come to mind.
The 2nd gear thrust washer is 1/8" thick when new.
I would suggest checking a shop manual.

See old carmanual project. The 1937-39 trans are the same and 1940-1948 almost the same.

Thanks for your reply Chev Nut.

I have the '37 manual and its' only reference to a dimension is 0.010" clearance for the second gear end float. I have 0.013".

I have several 2nd gear thrust washers , all measure 0.115".
also several 2nd gears , all measure 1.888" long.
All the second gears have worn teeth.

All energizer springs show polish but no wear.

All input shafts have worn teeth and front bearings are loud.

All needle rollers (input-output shaft) measure the same and are undamaged.

There is just a little wear on the main cluster bushes and some end float also.

Shifter forks have small wear , what is acceptable clearance?

I would really like to buy a new input shaft , syncro drum and second gear , but have been unable to source these.

I have read the later manuals , same info supplied as the '37.

could be a worn pilot bearing .

Thanks pushrod, the pilot bearing is in good condition.