While talking about a 4x4 swap with a coworker, he mentioned that he has a 1990 XJ he'd sell to me for $500 because it has a rear main and front seal leak. My question is, can I use this as a donor for 4x4 on my 1999 XJ 4x2 if I get the injection harness from the parts yard from a '98 and have everything work? He told me it has the NP231 and that basically sealed the deal in my mind other than the injection harness, as I'm sure it's not the same as the one in my '99. Would all of the plugs on the '98 in the parts yard match to the connectors on the '90? Any insight would be awesome. The '90 has 158K BTW, so even if I don't take the 4x4 off, it's still a no-freaking-brainer to buy it.

 

What type trans are in each ? This is the most changed area thru the years.

 

All three of them are 4.0's with the AW4, and the one in the parts yard as well as the one I want to buy have NP231's

 

Engine is easy. I have a write-up on that.

There's something about the Vehicle Speed Sensor part of the transfer case that's different.

The splines between a 90 AW4 and a 231 are 21. Later 231s are 23 spline.

 

Well crap.

 

If 90s a late production date could it be 23 ?

 

why not go the other way and use parts off your 99 to make the 90 worthwhile to drive?

 

Don't think so. A late 90 production date is gonna be a 1991.

 

But the only problem with the '99 is that it's 4x2