My 12 valve is backed by an NV4500, installed by the previous owner. I'm not sure how many miles are on it, but its been getting progressively more difficult to shift into third. The other gears can be stubborn at times - for example, getting it into reverse - but third gear is the worst. I'm pretty sure the third gear synchro is mostly gone, if not completely. I've also had a few occasions where it doesn't want to come out of 5th.
The previous owner said that he had an issue with the 5th gear nut coming loose and had it fixed. I'm not sure if it fell all the way off or not. I'm also not sure if he had the nut upgraded. Could this be the source of the issues I'm seeing?
I believe the previous owner may have also put a quart or two of standard gear oil in instead of the special sauce from Chrysler. I flushed the transmission since then and filled it with the good stuff. Is it more likely that my problems just originate from dissolved synchros?
Are there any sources out there for rebuild kits with the carbon synchros? All the ones I've seen so far have brass.