My vin tells me that I have a 88 xj 4.0 made in ohio,
but how can I tell what the gearing is?
Or which axels I have?
Any info?
thanks

 

Also Auto transmission

 

each have a tag... you axles should have a tag bolted on with the diff cover... they will tell you your gears... if you have a auto with a I6 then u probly have 3.55's... manuel... 3.07's... also search google for the pictures of your diffs... they will tell you what they are... your front is a Dana 30... your rear is either a d35, d44 or chysler 8.25... the D44 have a D shape to them with a steel drain plug on the diff cover... the other 2 are harder to explain and your better off looking at the pics...

 

I found out the info your looking for two ways, asking lots of questions, and search on this forum, theres a ton of threads on axles here, search!. As far as OEM info, Email Chrysler and ask for a build sheet, they can tell you what the Jeep was shipped with, granted that does'nt tell you what mods have been done by PO's, but it's a good starting point. Then search and go from there.

 

Rear end is easy, D35 has 2.62 inch axle housing, 8.25 has 3.00 inch housing. All you have to do is get under it with a tape measure and measure the housing, close to 2 1/2 you have a 35, looks like 3 you have an 8.25. Not sure about the D44, never seen one stock in a jeep although I have heard rumors.

Your gear is most likely 3.55, unless you had a tow package, then it would be 3.73. An easy way to figure it out is lift the front, support it so the wheels can turn and it won't fall on you. Mark the driveshaft and tires and turn the driveshaft. just a touch over 3 1/2 rotations of the driveshaft for a full spin of the wheel is 3.55, almost 3 3/4 is a 3.73.

 

The D35 also has a screw in plug where as the 8.25 has the lame rubber plug, apperantly an engineer having a brain fart that day!

 

There's a ID tip I didn't know, thought both were a rubber plug.

 

My TJ had a 35, screw in plug, my two Cherokees with 8.25's both have had the rubber plugs, can you say leaky leaky! Not the best design.

 

Anyway, back to the subject, I'd have to venture your running 3.55's. Obtain a build sheet, search rear end identification on this forum and go from there.

 

he would have the d44 if he had the tow package in this year... i found one in the junkyard and stuck it under mine... not a rumor... for real

 

my d44 had 3.54's though... but i have a 5 speed so a step up from the 3.07's

 

I do have the tow package, if that helps at all

 

I called the dealer and gave them nmy vin and they told me.