Manual Transmission Woes

[QuickOrange]

This transmission has been giving me trouble for a while now. I had it rebuilt, but the shop that did it frankly sucked. Before I could take any action with them, I moved out of state.

Anyway, I think it's an NV3500. I have a 90 model 5.7l 350 with a 5 speed. Right now I've got 4 issues and I was hoping someone here might have some suggestions.

First, it makes a humming noise that reverberates through the cab at about 40mph and up.

Second, there's a little bit of a lurch in first gear after a complete stop.

Third, it makes some sort of a "clunk" type noise when I turn the truck off. It sounds a lot like engine knock, but it's coming from the transmission. I've noticed that if I shut down the engine with the clutch depressed it doesn't make the noise.

Last, the clutch fork post is broken off at the tip. I would like to replace it, but I both can't find a replacement or figure out how to remove it.

Thanks!

 

[MIHELA]

Your 90 probably has the 5LM60, the predecessor to the NV3500. Don't be too hard on the shop, it's well known as one of the most difficult transmissions to rebuild. You would do well to replace it with a 94-96 NV3500 without the granny low. They made significant changes to the bearings and the shift mechanism.

 

[QuickOrange]

Thanks for your reply. What's the going rate for NV3500's? Are they cheaper/easier to rebuild, and is it a reliable transmission?

As far as "granny low", how do I discern whether it's got it or not?

Will my existing master and slave work?

 

[MIHELA]

The NV3500 is easier to rebuild and much more reliable as they got revised bearings. The old 5LM60 had 4 shift rails and the 3500 has 1. The shifter on the granny tranny says L1234R and the regular one has 12345R. I'm not sure whether you can use the master and slave you have. I think the average price is around 500-700, I'm sure there are deals around if you look, especially in u-pull-it type yards.

 

[QuickOrange]

Thanks, I'm going to definitely check into it. I've been wanting to dump this piece of crap transmission for years. Hopefully I can find what I need and not have any issues with it.