hey there guys and gals...I am new to jeeping and have a 1998 TJ with a skyjacker 2" coil spacer kit and 33x10.50's. Love the look. I have questions about the gearing and such. I bought the jeep used and i am unsure if it was ever changed from stock or not. I don't think was....I think everything is stock. I assume it has a dana 30 on the front and a dana 35 on the rear. How do I make sure?? How do I determin what the gearing is??? What  is the difference in gearing ratio's and how do I beef things up to stand up to some rougher than average trail pounding....I do not have a light foot!! Any help would be appreciated.  

what you have should be ok as long as the tires stay on the ground (no jumping) don't go larger than 33's, install a super kit in the rear with 4:88's or minimum of 4:56 gears (assuming you have a 4.0, 4:88's for the 4 banger min.) 4:10's aren't enough for the 33's nor will they help the mileage, take advantage of the overdrive tranny. if you figure on using a locker it will increase the chances of failure. there is a fella around here running 35's, on the 30/35 combo, yeah the brown jeep with no lift! aftermarket d44's can take most any kind of pounding the 4.0 can dish out along with some acrobatics.

O, on the front diff cover there should be a tag held on by two cover blots with your gear ratio stamped on it, clean it off you will be able to read it.  

Thanks for the help....I don't plan on going airborne just yet unless something goes terribly wrong    

Look for tags on the axle, often they will tell you the gearing and the axle. If the tags are gone mark a spot on the tire, jack that tire up and rotate it. Count the number of driveshaft rotation in one complete rotation of the tire. This is your rough gear ratio.  

THanks- Very Helpful  

Axle tags and diff cover shape, the two easiest ways to tell the identity of an axle.

Well that and I don't believe anything other than the 30/35 combo was ever offered in a TJ besides in the Rubicon package...  

the sahara offered a rear 44 i think  

axle identification

jeep tj FAQ's  

ya, i think regular tjs ( not just the rubi's and sahara ) offered a 44 in the rear  

the sahara and sport have the d44 as an option and the rubicon's only option.