What gears do I have?

[MattS]

I have a 99 Sport with a 3" lift and 31's going on this weekend. I wanted to get a new speedo gear to make the changover smooth but I don't know what gears I have. I'm guessing 3:73 but I want to make sure. How do I tell?

 

[Cherokee91Red]

Auto or manual? 6 or 4 cylinder?

If its an automatic 4.0 then 3.55, 4.0 manual 3.07. Not sure about the other engine.

 

[dmillion]

I don't believe a '99 sport would have come with any engine other than the 4.0, so your gears will either be 3.55 or 3.07, depending on transmission. Of course, if you didn't buy the Jeep new then you never know for sure what a previous owner may have done.

 

[Eagle]

Agreed, a Sport should be a 4.0L. Auto will be 3.55, 5-speed will be 3.08, and if by some chance it's a 4-cylinder it should have 4.10 gears. 3.73s were not used in 1999.

 

[MontanaXJ]

Look at the gear ID tag attached to your front axle diff cover.

 

[johnnyc]

Jack the rear tires off the ground and put the tranny in neutral. Have somone turn one of the tires exactly one revolution, while you're counting the number of revolutions the driveshaft makes.

If the DS makes 3.5 revolutions, you have 3.55 gears. If it makes 4 revolutions, you have 4.10 gears. And so on...