I ve read every thread there is to read about gearing...still some what confused. Ive also looked at charts, but nned opinions on those that have this set up. I have a 07 4 dr sahara, 4x4, 3.21 gears, 6 speed with 32in tires 2 in lift and 18 in wheels. I plan on keeping the 18 in wheels. I want to run larger tires (no more than 35in) probably 33s. Right now im pleased with the performance / mpg on the 32s. Would 4.88 be the right gearing to keep performance / mpg close or above stock set up? Am I wasting money by regearing or is it an absolute must. I do tow a 5 x 10 utility trailer, but not that often (Lowes run or the dump). Do not do any hardcore off roading. Is 4.88 to low of a gear? Should I not mess with the gears and just run 33s?

Thanks in advance for your opinions / comments.

 

Yours is a special situation. You are the first poster I've seen with those gears & tire size who is pleased with that setup. I would regear, 4.88's for me at a 35" tire. It will perform well, and you won't have towing issues,but you should expect to lose gas milage when adding a taller wider heavier tire.

 

if you're gonna stick with 33's i would suggest 4.10's. the power & mileage will be closer to what you're used to. 4.88s are great if you go with 35's or 37's and do hardcore offroading. i had an 07 with 4.10's & 33's and had no issues with power or mileage. Now i run an 08 with 3.73's & 33's. even though it's not a huge difference in gears, i really notice the difference between the 3.73's and 4.10's. i have an auto trans. you can pick up 4.10's pretty cheap in the for sale section. or wait for superior start production on the 4.56's.

just my .02

 

Texbook would say with your setup or (future setup) 4.88's would probably be what you want. As far as gearing vs. not gearing it would be a definite difference. Hehh I agree with Ge99ne, I'm surprised your ok with the power you have on your current set up. I think you'll be pleasantly surprised and happy with 4.88's and 33's. Superior has a great set of gears.

 

Thanks for your responses. I talked to my mechanic and he tells me if I run lower gears I will lose alot on the highway, turn more RPMs and cut engine life in half. I told him I want to run 33s and pull a trailer (1000lbs or less) occasionally, he says....3.21s will be fine. Now Im definately confused because I respect the opinions of those on this site, who say 4.88s are just fine. I do not need a tractor, but would like a little more power. Should I mod the intake and exhaust and if so wont opening the exhaust some kill my low end power? If not will I get a better response out of the jeep. Like I said before Im not unhappy with the jeeps performance at all, however, going to a slightly larger tire worries me that I will lose alot. I read on another site where a guy hsa the same gears and 6 sp manual with 35s and says he gets around just fine. Help!!!!!!!!!

 

Hmm, don't really have a response to that other than I've re-geared 5 or 6 of my own vehicles over the years all of which I have had a positive response with. Not trying to downplay your concerns but I think you might be stressin a little too much on this. Lol, as far as your engine life being cut in half well....There's a saying that goes "Don't believe everything you hear" Think about it, you have one mechanic that says one thing and how many people on this site with personal experience saying another . My opinion still sticks with if your going to run 33-35's and especially if your thinkin of pulling something go with the re-gear. Just me but I would go with 4.88's.

 

also, your gears may be lower, but with larger tires you simulate the stock set up. wouldnt it be nice to have a little pull in 6th gear?

 

First, your described towing is not an issue -- bringing a few building materials home from the building supply, taking some junk to the dump is all slow speed short duration towing. To me, the real question is: do you want the expense of re-gearing and up-sizing your tires at all? You are looking at a fair expense (gears, installation, etc.) to increase your tires by an inch in diameter. To go larger has even more cost (lift, etc). If you are happy with your Jeep currently, then weigh these costs carefully.

If you are indeed intent on re-gearing, ask your mechanic friend the costs to do so. You will find lots of used 4.10 and 3.73 gears for sale on this site, with quite a low price. Then you can do a tally. Also factor costs of new wheels (or spacers) and tires.

Also remember the 6-speed tranny is really two five speeds. Those with 3.21 diffs will mostly use 1 - 5 (and occasionally 6th on the highway, while those with 4.10s find 1st is a 'granny' gear, and could happily use 2 - 6 all the time. Performance comes at the price of greater fuel consumption.

Your call.

SV

 

Why not just get the tires you want, drive it for a couple of months and then decide if you need lower gears?