hey guys, i have a 99 2500 suburban 2wd. its lifted with 35 in tires and stock gearing, don't know size. i want to regear with a limited slip or posi unit to tow a 27ft camper trailer. (currently boatless ) i definately felt the lack of low end grunt when i lifted it and i'm worried about hills when towing. what gear size would you guys recomend? anything else like upgraded tranny cooler, ect..? BTW, its my father in laws trailer, not sure of weight.

any help would be appreciated.

with 35's i would at least make sure you get 4.10's or maybe even 4.56's...

with the 4.10's you will be turning about 1950 at 70 and 4.56 you will be turning 2150 at 70....(assuming a .70 OD ratio)

Sean is on the right track with your gears.

Minimum would be 4.10. I believe 4.33 is another option you may have. The next step being 4.56 like Sean said.


I had a 95 half ton 4x4 Chevy with 6" lift and 35" tires. I regeared to 4.56. This made the final gear ratio just a tad lower than the factory ratio @ 3.73 and stock tires. I towed quite a bit with my rig. Made for the perfect scenerio in my case.

My opinion, and yes I said opinion. If you plan on towing a lot, go w/ the 4.56. If most of the driving is not towing then go 4.33.

Oh yeah, throw a locker in while you're at it.

Buck

Look on the build sticker in the door jam or glovebox.

GT4 means it has 3.73 gears.
GT5 means it has 4.10 gears.

4.56 is/was not available from the factory.

Do you have a 350 or 454? Definately make sure you have a transmission cooler that works well, and keep your tranny fluid fresh. A transmission temp guage is a smart idea too.

Thanks guys. It is a 454 and the sticker says GT4(3.73). It has a small tranny cooler but I want to replace it with an aftermarket one. Any recomondations on good tranny coolers? anyone know a good shop in Orange County, Ca.?

Send a PM to forum member ' thisistank ' . He is in SoCal and has a 'burb jacked up like yours.

summit racing has a huge tranny cooler for around 35 bucks, just put one on my dually.

rieder or reider racing has anything you could want as for a ring and pinions and different lockers. i don't like most limited slips go with the detriot locker they are bullet proof and offer the best traction.

Thanks for the info guys.

If your staying w/the 35 inch tires 4.56 gear is probably going to be your best bet but keep in mind ANY driveshaft or part that isn't perfectly balanced is going to vibrate signifigantly due to the high rpm's,I have chased this problem MANY times after re-gearing customers vehicles,Smitty