tuner or gears for a hummer on warrenty

[slippy]

Im about to get my 37's and i was wondering what you guys thought. i need to regear or reprogram my computer becuase iv been there done that with big tires and have nothing to offset it, it sucks!
im under warrenty right now with 80k, and it goes untill 150k.
the chip can offset the gear ratio but i would have to untune when i go to the shop under warrenty.
Gears would be a one time thing, as long as my diff. doesnt grenade i shouldnt have to worry about it...

[Stellar]

Both..You don't have to have a tuner, but it will recalibrate your speedo for your tires / gear setup, add a lil hp/tq, and give you a few other adjustments that can be beneficial. IMO 4.88 gears is the ideal setup for larger tires, better acceleration and off roading for the Hummer. Especially for here in Moab, UT

[Hellz]

Originally Posted by Stellar

Both..You don't have to have a tuner, but it will recalibrate your speedo for your tires / gear setup, add a lil hp/tq, and give you a few other adjustments that can be beneficial. IMO 4.88 gears is the ideal setup for larger tires, better acceleration and off roading for the Hummer. Especially for here in Moab, UT

i was always under the impression to shy away from 4.88s for any kind of off roading, and dont think about it for serious off roading ( MOAB and such)

[guruerror]

Originally Posted by Hellz

i was always under the impression to shy away from 4.88s for any kind of off roading, and dont think about it for serious off roading ( MOAB and such)

I got the same impression from reading around...not to mention that the lower you go the higher your RPMs will be at highway speeds. I do a fair amount of road trips, so I wasn't trying to drop my comfortable cruising speed and/or decrease my highway gas mileage.

Since I was fine my truck's performance with the stock 4.10s and 35s (especially after the Performance tune from my Cortex), I tried to keep the overall ratio as close to stock as possible when I moved up to 37s. This calculator (http://www.4lo.com/calc/geartire.htm) came in handy in helping me make my decision...I went with 4.56s.

The tune gave me the little extra 'kick' that the truck needed and the gears kept me as close as possible to the overall factory ratio.

[Stellar]

4.88's really wake the H2 up in terms of acceleration and have definitely helped towing my boat. 4.56 and 37's will be close to stock, but if you add larger tires or any additonal weight you'll wish you went with the lower gears. The lower gears also help for crawling and descending on the slick rock trails in Moab.

[Hellz]

but will also sheer more easily than the higher gears....

again, this is from what i have read and what not.
i have no idea how crazy 4x4-ing these guys are doing.

but adding more teeth means something has to give to make room for them.
that is the groove depth.
so shallower depth, means finer teeth, means easier to sheer them off.