would regearing to a 4.10 be to low for running 31's trying to keep it as close to stock cause its my DD. how would it be on the highway?

 

why do you want to regear? 4.10 will decrease fuel milage. by how much Idk

 

I run 31's and I didn't lose much if any highway power.. Regearing is a waste, imo, if you aren't going all out

 

4.10's would put it back to a stock setup but it's really not worth the money if you started with 3.55's. The difference you're noticing now is minimal, so the difference you'd get would be just as minimal. Lower gearing will affect your hwy mpg's (lower), but not much if the gearing isn't an extreme change. I've got 4.56's and 31's (will be getting 33's) and i still get about 18 on the freeway.

 

I run 31s but just pulled a set of 4.10 axles out of a 4 cylinder xj at the jy. With the stock gears i think its noticably slugish pulling away from a stop but on the highway its not that noticable. I'm waithing for my 29 spline detroit to get here to replace the 27 spline open carrier. If this threads still up il let you know what i think of the 4.10s over 3.55s.

 

i have stock gears, 3.55s. and im running 32s right now. i wanna go to 33s or 35s in the future but instead of regearing i will probably just swap axles.

 

I'm running 3.55 in mine on 32's and I agree its sluggish off the line. On certain parts of the highway I gotta stay in the throttle to maintain speed. On hills at freeway speeds the tranny is always "hunting" through the gears to maintain speed. I'm planning on putting 4.11 in the rear and a matching 4.10 up front to see if highway and off the line manners will improve. If not,well it might be a little better with climbing off road obstacles.

 

For everyone thinking about 4.10's, why not just go 4.56's. They cost the same and you get better results. Plus, if you decide to go with 33's at some point you're already set up for them.

 

Mathematically, 3.90 ratio gears with 31" tall tires is equivalent to stock tires and stock 3.55 gear ratio. However, a 3.90 ratio does not take into consideration the extra weight of 31" tires and possibly heavier wheels as well. I would think 4.10 would come closer to compensating for both diameter and weight.

 

lol lol i would just go ahead and buy the lift to fit the 33's and get 4.88... that way you can bump up to 35s when you want, which at some point you more than likely will.

 

http://www.accuautoparts.com/calculatorfin.jsp I like this calculator.

 

sweet calculator!

 

No. I run 32's and and could barely tow a small popup camper through hilly country with the 3.55's. I installed 4.10's and it made a world of difference. It's like the camper isn't even behind me. It made no difference at all in my fuel mileage.

 

Here's the other calculator: 31" new tire / 28.29" stock tire = 1.09579 X 3.55 stock gear ratio = 3.89 new gear ratio with 31" tire equivalent mathematically to stock ratio using stock tire.

31 / 28.29 = 1.09579 X 3.55 = 3.89

 

If i were you i would just keep the stock gears for now.. Yes you do notice the difference now, but give it 2 weeks and you'll be pretty much used to it.