NV4500 rebuild and first gear swap

[The_Punisher]

I have a 93 GM NV4500 in my garage I pulled from the JY. Before putting it in my truck, I'd like to rebuild it. I have done axles and such lately, seems like a manual trans would be in my realm of ability.

Any special tools required? Any good manuals for rebuilding this tranny? Good source for complete rebuild kit?

Can first gear be swapped out? I have the low 6.34 first gear and would rather have the later 5.61 first. Right now my truck still has the tired 350, NV3500 and I'm running 5.13's with 38's. First gear is plenty even with that combo, and 5.61 would be a little more torque than that. AND I'm building a big block. So I know I don't want the 6.34 first gear, for me it would be worthless.

So would it be as simple as just swapping the gear itself? If so I bet I could just trade someone that wants the lower 6.34 gear.

[TrikeKid]

Can't speak to the first gear swap, but yeah you'd probably just need the gears off the main and counter shaft to swap. Bout the only special tools you need for a manual tranny rebuild is a couple bearing splitters, a shop press and some good retaining ring pliers.

[The_Punisher]

cool thats what I was thinking for the tools. I wish I could just buy a rebuilt NV4500 but they're at least $1000 and shipping a tranny that heavy to AK is a no go.

thanks.

Anyone know about the first gear swap?

[Marc]

I believe some of the gm versions had a harmonic balancer over the 5th gear nut. You need a special socket to access that nut. It looks like a hub nut wrench and is expensive compared to the dodge wrench. Quad4x4.com has all the tools and supplies you will need. They also will sell you a rebuild manuel. Can't answer definitively the first gear question but I think the counter shaft is one piece so I don't believe you can swap the first gear only.

[guidolyons]

Lots of good info on NV4500 and parts from High Impact and/or Mack's Trans

http://www.mackstrans.com/NewVentureNV4500Chevy.html
http://www.high-impact.net/transmiss...ear/nv4500.htm

Originally Posted by http://www.high-impact.net/transmission_and_gear/nv4500.htm

6.34 1st Gear & 5.61 1st gear units

High Impact offers brand new NV4500 transmissions with either 6.34 ratio 1st gear or 5.61 ratio first gear. For the first two years of production of these transmissions in General Motors vehicles, they were built with an extremely wide ratio 6.32 to one first gear.

While not as smoothly drivable on the road, the 6.34 ratio unit is in many cases the ultimate off-road off road manual trans. In vehicle using dual transfer cases or extreme underdrives, the 5.61 unit is generally better, as you don't need to squeeze that last little bit of low gear out of the trans

NOTE: The 6.34 ratio transmissions are available ONLY with the GM input shaft, and the early GM NV4500 bolt pattern. They are not interchangeable with the later GM or Dodge NV4500s. This is important to know as our bellhousing adapter plates must use the Dodge input shaft (it is longer). Therefore they MUST use either an early GM factory bellhousing, or several aftermarket full bellhousings we offer to use this transmission with AMC and GM engines. Conversions must be specifically designed for this transmission. We CAN supply them with GM or Dodge output housings/shaft.

[The_Punisher]

thank you very much for that reply, answers my question well