H2 Manual Transmission Swap

[rao]

I am pretty sure this is the first one anywhere

Supercharged Hummer H2 with every conceivable suspension and other upgrade now has a NV4500 manual transmission and a manual transfer case, all from a 3/4 ton Silverado.

Now it is no longer full time AWD, but can be switched into rear wheel drive for very impressive smoky burnouts (which it does quite well) and almost 50% better gas mileage than the race-built 4L65E auto transmission. It was done because the truck had gone through three 4L65E's and kept breaking tail shafts and the owner wanted a real transmission



Note smoke from the back tires only and how the truck is starts to rotate and then straightens out







and yes that is how clean the truck is after we worked on it.

The NV4500 and NP263 went in without a hitch. The only real trouble we had was the clutch pedal. The dash on the H2 must be different from the Silverado and the clutch pedal bracing wanted to go where the Body Control Unit was. Not to hard to fix, but it took a while.

[rao]

Clutch Pedal and Manual Transmission Brake Pedal



Shifter - a short shifter was made using part of the stock manual transmission shifter and a tie rod end to provide the correct geometry to shorten up the shifts. He hasn't finished up the custom console yet, but the cupholders willsitill fit and it will look stock when it is all done







Transfer case shifter. The handle needs to be modified so that it comes out on the outside of the center stack, but that is a no-brainer



The NV4500



I am also selling the auto transmission, transfer case and other odds and ends that are no longer needed.

[DRTYFN]

What inspired you to do the swap?

[rao]

The owner kept breaking the output shaft on the auto transmission (the car was on it's 3rd transmission, a very expensive fully built racing type, which wasn't all that pleasant to drive) and any upgrade would have required a different transfer case (you an do a 4L80E to the Hummer xfer case but the output shaft on the 4L80E has to be turned down defeating the purpose) and he wanted a manual transmission.

[Desert Dan]

Great Job and Gearbox.
The NV 4500 has a granny low!

I wish GM offered a 5-speed option from the factory

[rao]

1st is definitely a granny gear, especially in 4WD Low . Starting in second is the way to go.

[Alt-F4]

How much stronger is that set up over stock ? How much does something like that cost? I like it

[rao]

The transmission is much stronger than stock; the NV4500 transmission is rated for 14.5k lbs gross vehicle weight. The swap was not inexpensive, especially since we used all new parts. I'd guess the cost was over $6k in parts.