Gears

[jeepman 87]

I have an 89 mj with an 8 inch lift and 35's. I'm looking at gears but I want to drive on road but also have fun on trails and mud. What size gears should i use

[HOrnbrod]

4.56 gears w. 35" tires will put you @ approx. 2134 RPMs @ 65 MPH. That's pretty close to factory gearing:

 

3.55 gears w. 28" tires = 2,076 RPM @ 65 MPH.

 

With 35's you could even go to a 4.88 ratio (2,284 RPM @ 65 MPH). Depends on where you drive most regularly, street or off-road. .

[jeepman 87]

Where is a good place to get a set of gears

[MuddFoot]

4.56 is what i ran on my 88 xj with 35s. adams driveshaft and offroad was the best price i could find when i ordered my gears. but i ordered lockers and carriers and covers. they made me a package deal. if you plan to go bigger i would get 4.88s 

[SW86]

I'm running 4.88s and I just got mine from 4wd since we get the discount and there's always free shipping. Make sure to get the master install kit as well.

[mvusse]

I would not run 4.88s in a Dana 30. The pinion is so freakishly small it would create a weak link. There's a reason Dana never made a 4.88 gear set for it.

[Eagle]

I have an 89 mj with an 8 inch lift and 35's. I'm looking at gears but I want to drive on road but also have fun on trails and mud. What size gears should i use

4.88s

[SW86]

I would not run 4.88s in a Dana 30. The pinion is so freakishly small it would create a weak link. There's a reason Dana never made a 4.88 gear set for it.

 

I've seen two 4.56 and two 4.88s in a 30 all bust the ring gear and the pinion was fine. Ill agree it is freak like small but it will still stand up to some punishment..... For awhile at least lol

[mvusse]

The small pinion only engages one tooth at a time, causing the ring gear failure.