Transmission Problems

[graham]

When I bought the truck about a year ago when you go to shift into fifth gear it would jump out of gear. I put new synchronizers in it but it still jumps out of fifth gear but I noticed when I put the parts on the shaft were loose. Could the shaft be bad and causing it to jump out of gear?

 

[Jeepsinker]

I wouldn't suspect the shaft as the problem first. I would check shift forks for wear, check the roller bearings where the mainshaft pilot rides on rollers inside the back of the input shaft, and maybe the Dogs and dog springs on fifth.

 

[m-35tom]

the forks do not hold any gear engaged in this trans by design, remember this is really old trans. also the syncro dogs are cut straight, not on any angle like modern trans are. what holds the trans in 5th is a feature machined in only one side of the spline on the front of the main shaft. some are cut deeper than others. it should only try to come out on decel. pulling it should try to engage. what holds 2 and 3 in gear is the feature cut in the middle of the hub that 2/3 syncro is on. some of these are also much deeper cut than others so work much better.