I know this has been asked hundreds of times and I've read many of them but I haven't found an answer for my situation.

So, I have a 92 xj with a 5 speed and 31s. It has 3.07s right now and it sucks. All the info I've found says that 4.10s would be the best all around, but they are usually talking about an automatic. I just wanted to make sure that would also be best for a 5 speed application before I make the investment.

Its my daily driver/ camping rig with some mild trail riding. I pull a small trailer sometimes. I also have no plans of going any bigger than 31s.

Thanks!

 

4.10s will do just fine. Find a set of axles from a 4cyl XJ, should have 4.10s

 

I'm currently running 4:10's on 32's with a 5 speed. And while the power is great, my speedo is about 16% fast. And I run around 2300 rpms on the highway around 65mph.

If you don't plan on going bigger than 31's then is say just go with some 3.55's out of an auto

 

Thanks. I just wanted some confirmation. somebody told me that 3.73s might be better for the 5 speed do I just wanted to make sure my origional plan was accurate.

On a semi related note; with it being a daily driver with light trail use should a dana 35 be strong enough? I'd prefer a 44 but a 44 with 4.10s is kind of hard to come by in the junk yards where I'm at.

I'm just trying to check my plans before I start spending money so I can do it al right the first time.

 

Wow 2300 rpms seems a little high.

I'd like more power but still keep some mileage.

Maybe 3.73s would be better. ?

 

3.54 from an auto would be a good upgrade, and cheap and plentiful.3.73 would be great too, I wouldn't go and lower than that though,

 

3.55s would get you close to to what it was with stock tire size. I'm doing the swap now on my 94 ax15 with 30in tires and 3.07 gears. picked up a cheap parts XJ with 3.55 gears, Chyr 8.25 limted slip in the rear.

 

You should have an effective gear ratio of 3.57 with 4.10 gears which would be a really good setup for a DD with some light wheeling.

Old tire diameter, divided by, new tire diameter, times gear ratio gives you the effective ratio.

27/31x4.10=3.57 new effective ratio

27/31x3.07=2.67 your effective ratio now.

 

no that is right on target to be in or around the power band

 

So this is going to make me sound really ignorant but i dont know what this means.

 

No this doesn't make you sound ignorant, I didn't know either until I asked someone.

If you have stock tires they are about 27 inches tall, with a 5 speed your gear ratio is normally 3.07. If you install 31 inch tall tires and keep the 3.07 gears your effective ratio will be 2.67, in other words although you didn't change the gear ratio it will perform like you have 2.67 gears installed instead of the 3.07 gears.

My Cherokee has 4.88 gears and I am running 35s so my effective ratio is,
27/35x4.88=3.76

 

Awesome. That makes a lot more sense.