Changing gear ratios in the NV4500
 

This is for the 1999 Chevy Silverado 1/2 ton 4x4. Still running the 6.0 (LQ4) with a nearing future with front mount turbo setup. The NV3500 transmission just isn't going to hold up (been through 2 of them). I want to keep the 4x4 by way of NV4500 with an NV261HD transfer case. If so, would I be able to have the gears changed so that first gear wasn't such a "granny" gear? Since Low is only used for Towing and/or off-Road use it wouldn't be usable for the street driven application. If it can be done for a decent price I may change the ratios of 1-5

:barf: Model Low/1st 2nd 3rd 4th 5th
NV4500 5.61:1 3.04:1 1.67:1 1:1 0.73:1

I have read complaints that some NV4500 guys had about not being able to grab 3rd gear when heavy on the pedal. Can anyone confirm this or any other potential problems? It would help me a great deal before I lay a bunch of cash into getting the NV4500 built with the gear ratios I want.


Thanks very much,
Eric

I don't know of anyplace that will can change the gear ratios in the trans. Just start in 2nd all the time, that is what I do. As far as the 2-3 shift the NV4500 has heavier shift gates so it takes a little work to get it in gear, the real problem with the faster shifting is the master/slave cylinder releasing the clutch at higher rpms. Search "clutch drill mod" or slave drill mod. There is a hole in the slave cylinder from the factory that limits how fast the fluid can pass through, meaning slower disengagement of the clutch, all you have to do is drill out the hole and it is supposed to work better.

The NV4500 is a good solid trans, but it isn't built for a sports car, it is built for high torque and heavy loads. I know that my truck would be quicker in the 1/4 mile with a 4l80e but I like driving a stick so I take the sacrifice.

How do you like starting in 2nd with those 4.10's in the rear? I know about the "clutch drill mod". I will most likely, give it a try when the 4500 goes in for the heck of it but in all honesty I never had a problem shifting the 3500 fast. Like with doing anything else, after doing it for a while, ya just get good at it and do it fast!...even the sloppy truck xmsn's. Hopefully, the 4500 will hold up to the added torque of the turbo on the 6.0 . I'd really like to see how well it performs in those 4 high launches, without breaking transmissions in the process.

2nd isn't a problem, I really only use first if i'm on a hill or have a heavy load. It should be even better for you, as your not pushing as much weight around. I wouldn't worry about the trans breaking at all, but the rest of the drivetrain around it needs to be in good shape. And the clutch, I had to replace mine right after I did the radix, as it just wouldn't hold under boost. But I had worked the stock clutch hard getting the truck stuff off road etc...so I had probably glazed it already.

4 hi launch in 1st is fun, but depending on gear and tire size you only get to about 20 before you have to shift.