Manual Tranny Problems! Please Help

[blktie96ss]

My wifes 93 4.3L 6cyl truck is experiencing a little issue with the manual tranny. The tranny has 168,000 on it and has had no clutch issues to date. However it is not wanting to go into fourth gear. If you shift around the pattern a little something cures itself and then it will go into 4th. Things will be fine and then it will do it again. I have worked on many auto trannys but not real good with manuals. Any insight would be appreciated!

Thanks
Shawn Tillotson
Split Decision Customs

[GMMerlin]

Sounds like a shift fork is worn

[wafrederick]

I have some bad news,replace the whole transmission.GM does not make any parts for that one.The old one has to be sent in and a new in it's place.My father called for parts for one of them once from the dealer and no parts listed for that one.

[tRustyK5]

Dealers are wankers, and lousy places to get parts (mostly)

Check here for NV3500 parts...

http://www.rsgear.com/NV3500trans.htm

And another source here...

http://www.midwesttruck.com/TrancatPDF/NV3500.pdf

The unfortunate part is that you can't just remove a top cover to work on this particular tranny. The earlier Getrag is the same way...integral bellhousing, all aluminum case etc etc.

I'd suspect a retainer pin sheared on the 3-4 shift fork. Do all the other gears operate correctly?

Rene

[blktie96ss]

Originally Posted by tRustyK5

Dealers are wankers, and lousy places to get parts (mostly)

Check here for NV3500 parts...

http://www.rsgear.com/NV3500trans.htm

And another source here...

http://www.midwesttruck.com/TrancatPDF/NV3500.pdf

The unfortunate part is that you can't just remove a top cover to work on this particular tranny. The earlier Getrag is the same way...integral bellhousing, all aluminum case etc etc.

I'd suspect a retainer pin sheared on the 3-4 shift fork. Do all the other gears operate correctly?

Rene

Sometimes it acts up downshifting to second or first gear. I really noticed it when it got very cold this past morning. Once she warmed up it got better. Want to change the fluid since it is original, but can not find any specs. on what type it takes.

[chevrock22]

Originally Posted by blktie96ss

Sometimes it acts up downshifting to second or first gear. I really noticed it when it got very cold this past morning. Once she warmed up it got better. Want to change the fluid since it is original, but can not find any specs. on what type it takes.

In manual trannys you should not have to change the fluid.

[79403ta]

Its basically gear oil (GL 5) and it is good to change it it sure wont hurt it to be changed that way you can drain some of the fine shavings out (normal wear on the gears)

[tRustyK5]

Originally Posted by 79403ta

Its basically gear oil (GL 5) and it is good to change it it sure wont hurt it to be changed that way you can drain some of the fine shavings out (normal wear on the gears)

You just need to be sure it doesn't require 'syntorq' like the NV4500 does. If it requires syntorq and you put in regular 80W90 gear lube it'll mess up the syncho's.

Some manual tranny's use ATF too...your owners manual should specify which fluid your tranny needs. It couldn't hurt to change the fluid.

Rene