Should I re-gear for 30's?

[nosajwp]

Right now, I have a 2001 4.0L auto with 3.55's and 225/70/16 tires. I'm thinking of going with either 225/75/16's or 245/70/16's. Do you guys think I need to re-gear? Would I notice much of a power or mileage difference?

 

[roke40]

I'm runnig 33s and still haven't regeared. My mileage sucks right now but it's still driveable. You'll be fine with 30s. Others will tell you to go to 4.10s but if you enjoy wheelin with the 30s you'll want to go bigger sooner rather than later. Regearing is expensive so you don't want to do it more than once. When you're ready to go to 33s then regear. I'll be getting that done as soon as I get the money in the bank. It might be a while with baby # 2 on the way.

 

[Fergie]

I regeared to 4.10s with 30s and an auto.

Awesome in the rocks, and runs just fine on the highway at 75mph.

I'm moving to 4.56s and 31s very soon.

Fergie

 

[scottsxj]

you dont need to re gear, i am running 30 inch tires now and i hardly notice a diiference from stock. HTH

scott

 

[Eagle]

You'll be okay with 30s and an automatic. I've run 30s with a 5-speed and that's, shall we say, less than ideal. IMHO 3.73 is the "right" gear for 30s, but it isn't worth it to spend the money to go from 3.55 to 3.73. Stay with the stock gears and worry about regearing if you later decide to go bigger.

 

[BillR]

You'll notice a difference, but it shouldn't be too bad. I ran 3:55s and 235s for a short while, and it was fine.

 

[WobblesXJ]

I have 3.55 with 31's and wish I had alittle more leverage but it's drivable. I'm not towing anything or doing any harsh wheelin' so I'm ok for now. Figure I"ll regear when I swap out that wimpy D35.

 

[FUNKYTEE5]

Right now, I have a 2001 4.0L auto with 3.55's and 225/70/16 tires. I'm thinking of going with either 225/75/16's or 245/70/16's. Do you guys think I need to re-gear? Would I notice much of a power or mileage difference?

I went from 3.07 to 3.55 in my 5sp XJ with 30's. Kinda wish I had gone 3.73. But even with 31's it'll be lower than stock. Stock gearing is just too tall. I'm not sure about AW4 guys? Does the converter lockup in OD? I do tow a boat that weighs more than the jeep though

FUNKYTEE5

 

[riverfever]

I'm stock gears on my 96 and 31's. I do notice a difference now but it is def. not a PITA. I have an auto.

 

[Bmxpunk1369]

just get some new axles, i hate gears, i cant figure them out and id rather swap an axle any day than have to do all that work just to find out i messed something up. You could look around a junkyard or forums for a 4.10 set for prob 500$ or less.

 

[ChuckstrPT]

Right now, I have a 2001 4.0L auto with 3.55's and 225/70/16 tires. I'm thinking of going with either 225/75/16's or 245/70/16's. Do you guys think I need to re-gear? Would I notice much of a power or mileage difference?

I'm running 255/70/16's on my '01 with stock gearing. That's about a 30x10.00. Daily driving is really not noticeable. I chose the 255/70's over the 245/75's to save a little on the gearing (the 255's are slightly shorter). If money is an issue don't bother. Having wheeled other vehicles I can tell you that gearing should be a priority(I wish the 4to1 tcase wasn't so expensive!), and is money well spent, but with a 30 inch tire, you really haven't gone far enough to justify the expense. If you never go bigger it would be a waste of money. If you regear for 30's, you'll want to regear again when you get to 32's or 33's. My grand plan is to wheel these until I wear them out. By that time, I hope to have created enough room to fit 32's or 33's, and we'll likely grab the deepest gears we can with our 8.25 rear end (4.56?).
My $.02- don't waste the money on gears now. wait for larger tires. Invest in a locker for the rear. That would be money better spent now.
HTH