Im gonna put a ford explorer rear in my 91 cher its a 31 spline do i or how do i check to see if i need to change my front for gear ratio reasons

 

you need to know the gear ratio of the axle that you have gotten and the ones in your jeep. If you have an auto xj then more than likely you have 3.55 gears... not always though. If your jeep came with the tow package you can have 3.73 and if you have the very off road package ( this is what i was told it was called ) you might have 4.10.... if you have a manual trans in your xj then you most likely will have 3.08. Hope this helps.

 

mark a front tire, mark the front driveshaft. roll the jeep forward slowly, and see how many times the front drive shaft turns for 1 full revolution of the wheel.

 

seems to me most 8.8 with 31spline and LSD were 3.73 or 4.10.


This may help too

https://www.cherokeeforum.com/f30/fo...wap-info-3847/