Hi all. I had my nv4500 rebuilt last week, and upgraded to the SB hydraulics while it was out. Most gear changes work fine, but it has issues going into 3rd from second and also downshifting into 3rd. Upshifting, I have to wait for the motor to go back to an idle before it will go into gear. I press the shifter in the 3rd gear direction and I can feel it skip over something that feels like teeth sometimes. It did this before the rebuild and hasn't gotten better. When down shifting, I clutch, burp the throttle to the approx correct rpm, and it will shift into 3rd nicely. Without this, it refuses to down shift at any reasonable road speed. Shifting into the other gears has gotten better, so I believe the company that did the rebuild did actually installed new parts/syncros. If they did in fact install a new synchroniser, what is causing the problem? Could whatever the synchroniser acts upon be worn out, and should have been replaced? What parts does the synchro act on? I believe these transmissions are supposed to shift "car like" when functioning totally as designed. Is this correct? Am I just not driving it properly? Any ideas?

 

Sure sounds like a synchro problem to me. i thot fluid type at first but then you say its ONLY 3rd gear....

 

Fluid is correct - I have a yellow oem tag from NV that says the part number to use and bought 5 qts from a dodge dealer. What puzzles me is that I really believe they replaced the syncro. That's why I asked about parts the syncro acts against.

 

Could be a worn stop ring (terminology?) which has a cone shape to it to match the fiber material on the synchro ring. If the old one was chewing it up in a certain manner the two might not be matching up right. I'd vote on another teardown to see how it looks now, look for any uneven wear or excessive material in oil. I wouldn't think that a fork out of whack would do that only in third, but who knows? If it isn't any better after rebuild then there is something wrong, thrust bearing, or something in the synchro setup. Good luck.

 

Thanks Gorms,
I found some pics, I'll talk to the shop. Any other ideas?