top loader 4 speed kicking out of gear

Having problems with my top loader 4 speed kicking out 3rd gear. The transmission has brand new syncros,2nd,3rd,4th gears,new rebuild kit and new hurst shifter. It also has new shift forks. What else could it be.Any help would be appreciated. Thanks for your time.

 

Did you replace the entire synchro or just the brass rings?

 

Check the detent ball on the shift rail. That's really all that holds the shift rings in place. pull the cover (oops, gonna be tough with a TL...) and make sure the rail is actually clicking into place.

Also, did you check that the shifter throw and trans lever throw match? Put the shifter in 3rd, disconnect the linkage from the trans lever and wiggle the lever to make sure it's on the detent in the exact same spot.

 

Squirrel is pointing you in the right direction.Also,what were the symptoms BEFORE you started to work on this transmission.If it didn't do this before,check your work.If it did pop out of gear,then other parts need to be replaced other than just the brass.

Typically,if a trans is jumping out of gear,I replace the gear AND sliding clutch.I check for wear in the fork.I check the shift rail for being bent.Also the detent spring.

 

Thinking the same about ingagement teeth on the gear and the flutes on the slider. Is it a fresh shifter install? 3rd gear stop maybe set incorrectly.

 

Also, check the end play of the synchro itself. It may be a thrust washer thing.

 

thanks for the replies, the synchros were complete assembly's and the shifter is fresh. 3rd gear stop is backed all the way out. The transmission before being rebuilt would from time to time jump out of third. This is the 5th top loader i have rebuilt but the first with this problem. I had also thought about the shift rails and detents. Thank you all

 

a friend of mine got a "rebuilt "toploader had a jump out of gear problem ,found a circlip missing from one of hubs ,

 

Whilst I am certain that it is not the problem in this instance. I had the fourth gear popping out on me on my Saginaw. Only would happen when I backed off the gas.

Found that the bolts between the box and bellhousing were loose, and that there was a small (1/4") gap opening and closing between the bellhousing and the box. Once all the bolts were tightened, problem went away.

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I was going to mention the bellhousing alignment possibility...but that only causes problems in 4th, since it makes the input shaft misaligned with the mainshaft. Since 3rd gear and the synchro are both on the mainshaft, it's highly unlikely that that's the cause of the problem here.

 

Squirrel is correct on what he said. There had to be more things going on as well. Clunk's and banging sounds, hard to shift or put ingear, things like that.

 

shifts fine from 1st to 2nd, third feels notchy compared to my others, took it out to day to look it over, I still think it is in the shift rails and detents. I will order new ones from david key and let everyone know if it stays in gear.One more note the reason I rebuilt it is because 3rd and 4th shift fork fractured and was causing problems. Thanks for everyones input.

 

new shift rails and detents are in and transmission back in the car. Need to put interior back in and test it out. Tranny feels alot smoother than before. I will let everyone know how it does.Thanks for everyones input.