Recently my transmission (NV4500) started jumping out of third gear on acceleration. I can hold it in gear, which keeps it from jumping out. It is getting progressively worse, and I want to take care of the problem before I have a catastrophic failure. Daily driver you know! What could be causing this, and what do I need to do about it?

Another update. Coming home today I could barely get it out of fifth, and could not shift into fourth. I finally got it back into fifth, and fourth but it was very hard to shift. Sitting still it is hard to get in third, fourth, and fifth. IT WILL NOT GO INTO REVERSE AT ALL. It feels like it does when you try to shift from fifth to reverse. The shifter just slides down and left of reverse. Got any ideas so I know what I am getting into?

 

for a start, how is your clutch and related hydraulics?

 

cant say for sure but my buddies did that and it turned out his main shaft was either bent or twisted i cant remember which not sayin thats for sure it might drain ur tranny and look for metal shavings.

 

I am pulling it. So far the magnets are hairy scary! Lot of metal shavings. No chunks.

 

might need to replace ur syncros

 

I got the trans out and decided to pull the top cover and tail housing to see if I could locate the source of this problem. When I pulled the tail housing I could see that two bolt heads were missing from the main shaft rear bearing retainer plate. Huh! Found one bolt head and two washers in the main case, and the other head fell out of the tail housing when removed. Nothing appears damaged, so I'm going to replace those bolts and see if it will shift on the bench. If so I'm gonna put it back in and see if my problems are solved. There was a lot of play in the main shaft assembly with that retainer plate loose. Anyone know what size and thread pitch the bolts are?

 

Bolts are 5/16 - 18. Got it all clean and put back together. It shifts like a brand new one. I sealed the flanges with loctite 518 and filled it with 5 qts of Amsoil MTG. A couple hours of inspection time saved me about 1600 bucks