here are some pictures of the bevel on the syncro ring of the fifth gear. to remove the fork you have to drive out the two 5/32 roll pins, flip the ring should fix your problem. Please update us.

 

Again, thanks for the suggestion but I this already has a fully splined shaft with an updated nut. The nut is not loose and the shaft and gear are not stripped or broken.


Nice catch, surprising that 5th ever worked at all like that.

Today I got it apart, and ended up messing with the 5th synchro until I could see the thing actually lock into 5th when my wife shifted it. Yesterday I didnt verify this and must have put the inner ring back on wrong. Put it back together and verified 5th operation prior to wasting another gallon of gear oil and powerlifting the propshaft. Everything was good, filled it up and bolted it all back together and drove around town for 3hrs today, 5th is working great at the moment.

I was thinking the root cause of this was the snap ring being installed backwards by the rebuilder, because when I looked at it today the inner edge was chamfered on one side and not the other. Such that under enough pressure it would pop out of its groove and rub the inside of the tail housing- cause a lot of endplay in the 5th synchro assembly and keeping 5th from locking in. This idea made even more sense considering the initial failure was on a nice hard powershift into 5th.

Jet now that you have noticed that my outer ring isnt beveled, let me ask you this, is that part symetrical- meaning if installed backwards could it be possible for 5th to work at all? Does the outer ring come in a rebuild kit? I only ask because if not, perhaps my outer ring is an aftermarket rebuild part and does not have the bevel that the original ring came with. Otherwise I would have to think that the chamfer I saw on the snap ring was wear from the initial failure and not by design- meaning that the root cause would be the outer ring installed backwards is a problem for hot rod powershifting your NV4500... and before I do any serious mods I should flip the ring (maybe replace it) and replace that cracked shift fork.


Jet I really appreciate your help here, I owe you a beverage or 12 of your choice for sure. Do you have a good supplier for individual NV4500 parts? I guess I can always try the dealer but I have never dealt with the local Dodge place and not sure yet how helpful they will be. I think if I am gonna drill those pins out and pull that outer ring that I am going to go ahead and get replacement parts ahead of time. I called the local Transtar place and the idiot on the other end of the phone didn't even believe that Dodge put a manual transmission in a '98 Ram.

 

Thanks for the update. I believe the outer synchro ring is not symetrical longitudnally from the shift fork center line. It is possible that the synchro ring is holding just on the edge (not fully engaged) of the fifth gear itself and when that snap ring moved it gave it more play to keep it from engaging.
The snap rings sometimes have a sharp side and a rounded or beveled side most people I have met dont really pay that much attention. Good attention to detail!! I think that this is from the forming process of the ring in other words the stamp. But I always try to install snap rings with the sharp/flatest side in. In most cases a snap ringed item isn't designed to carry thrust loads to well(mostly radial loads).
I will have to check with one of the DB moderators to see if there is a Transmission parts vendor/sponsor here on Diesel bombers who can get theses parts.
If not I can get the parts usually one day but dont want to overstep a vendor/sponsor here at DB.

 

When you are ready to replace the parts you don't have to drill the pins out of the shift fork. All you need is the correct size of pin punch and the pins drive out and can be reused.

 

Updates??

 

Please update.

 

Going to close the thread for now. Can reopen the thread and update.

 

Sorry, been meaning to update- it has been about ~400 miles? and absolutely no problems whatsoever. I am going to rebuild the driveshaft soon and at that time I will pull the tailshaft housing again and reinspect. I need to reseal it anyhow with ultra grey since the ultra black did not work

THANKS FOR ALL THE HELP

 

Updates??

 

Going to close the thread for now (sounds like issue fixed). Thread publisher can reopen and update.