Rear end gearing ?? what to get?

[liftedboost]

hey guys im not very good at the rear end gear ratios and stuff so im seeking some advice or help on what gearing to order for my truck, its still me daily driver and mods are in my signature, main thing is its pushing the 35x12.50s on it so trying to find something suitible for my truck . im not 100% on what my truck had now but ive been told it has the 3.73 in it,how can i find out what gears i have?

[pl4yboy]

Check the glovebox codes, VIN, and if all else fails, pull the dif cover and go to counting. If you're a 4x4, you know you'll have to change fronts and backs right? That is, if you don't ever use 4wd.

[11 6.2]

Well from what Ive read it seems like the turbo guys normally run a higher gear ratio... That being said with u havin 35's that is prolly about right.. Others will correct me if im wrong.
If u post up your vin # there r some very very sharp guys on here and they can prolly tell u or find out for u quickly.

[WARLOCK]

is there a gt4 or gt6 and or g80 code in your glovebox

[tanz45]

Ran 4.56's with my 35's. Perfect!

BUT..I never did the front. If you don't do the front right away you have to take the front drive shaft out. Its a slip yoke and it will NOT leak fluid.

You have to take it out because teh front drive shaft is always spinning even when in 2wd.

[liftedboost]

truck is 2wd not 4x4 ......just looks 4x4 lol im gonna go check the codes real quick

[WARLOCK]

If its 2wd then it will be gu4 or gu6 i believe

[liftedboost]

well all my stuff in the glove box kinda faded away the writing on the tag. ill probably call the dealer and see what it has in it through them,

[Sleaper]

If you've got 3.42's, get 4.10's. If you have 3.73's, get 4.56's. That will keep you in the same RPM range as you are with your current gears if you still had stock tires.

[oleshifty]

i'm running 315/75/16 on a 2wd 5.3

had 3.42, truck was a TURD, got a best of like 15mpg.

Got a new rear with 10k miles...3.73 g80 locker. Truck is a little better. If it's raining, i have to feather it, and can kick back end out up to 35mph if i hammer down. If it's dry, i can normally get a small squeal/chirp....but truck falls on it's face until about 15-20mph, and pulls strong til it shifts at 45ish....then back on it's face until 65ish.

At 80-90 mph, i'm turning about 2000-2200 rpms. Bogs out real bad...downshifts at most hills...get like 10-12 mpg

At 65, barely have to push the pedal. Get about 14mpg, doesn't downshift unless the hill is steep.

Truck gets GREAT mileage at 45-50mph (well..great for this gas hog...get like 17-19 at this speed)

I plan on putting in a 4.56 when funds permit. Should bring my optimal speed for gas mileage closer to 55-60. Will be turning a lot more rpms but will be less of a load.

At 65mph, i actually get better gas mileage in D then OD.



i just ordered some software to monitor how much fuel I'm using, to calculate instantaneous mpg. I will make a log of this over a road trip, and post results.


**sorry about the novel**