NV4500 LD or HD

[Richard2112]

Originally Posted by '63GENIII

My NV is of the 1994 (early series) vintage with the lower 1st gear and the non syncro reverse. As far as I know, The newer generation cannot be retrofitted with the lower 1st gear and the older cannot support the syncro reverse either.

The 2wd models seem to come in a short and a long version. When I rebuilt mine, I noticed that the 5th gear nut on the short 2wd model was also holding the vibration damper and the fixed yoke on as well. Im not sure if that has anything to do with the lack of 2wd 5th gear failure reports but it is a difference worth noting. IIRC, the 2wd nut is also larger than the 4wd unit.

The newer units also used the "square top" shift tower as opposed to the earlier "round top" shift tower. Apparently the round can be converted to square if you know what you're doing. The advantage is smoother shifting as the round top style can be prone to dragging the shift forks and notchy shifting.

Thanks for all the replies. Being green at this trans-swap thing presents alotta questions that (I'm certain) may seem obvious to those who have years of experience. Additionally, I have no access to various other parts by which comparisons or measurements can be made. So, I have to ask those who know and I'm going to ask some dumb questions to be sure.

I have the (early) shorter GM NV4500 without the vibration dampener. '93 I believe with 35 spline at the yoke. It's what I have been able to find and it's what I plan to work with. My intent is to upgrade as much as necessary to have a clean, dependable trans.

I'll post some pics of it later but for now I have a question (or two) concerning the top cover. Mine is the round, bottle style cover and I would like to upgrade the cover for the smoother shifting characteristics I have been reading about.

I do not know if I can put the later square style top cover on it to get the added advantage of the better shift. Perhaps it would be a direct swap or possibly require some modification to accomplish.

Could someone please advise me on this? I see top cover assemblies on line that state "for 98 and up" or "for 95 and up" but I wonder if that is only because the cover was originally designed for those years or perhaps it actually works on other years also.