If you use the TCU that matches the '98 version it *might* work. That is assuming the signals that come from your '90 PCM are the correct voltage to work with the '98 TCU.jlake1 said:My question is: Are there any OTHER differences between the 90 AW-4 and the 98 version that would prevent this from being a plug and play swap?
jlake1 said:I do have the 98 TCU. What year did they change the signal voltages?
So what your saying is you can use any AW-4 as long as you have a TCU to match your engine and the correct input gear for the T-case. You just have to swap the connectors on the tranny to match the existing harness?Ed A. Stevens said:
They never changed.
The AW4 feed voltages are the same, the connectors and the output spline count changed.
Splice in the 90' connectors.
The only other change is a slight difference in the OD-4th gear ratio (0.70:1 to 0.72:1., or the other way around).
BTW, I run a 97 AW4 in my 88 XJ (same style of swap).