WIll an AW4 from a '91 fit a '96?

[SimpleXJ]

The '91 has a NP242 and the '96 has a NP231. Will it work?


Thanks guys

[SimpleXJ]

bump

[5-90]

According to my copy of Hollander's, the only big difference is in the TCU - the 231 was found behind the AW4 in the Pioneer and Laredo, and the 242 behind it in the Limited (I have two of the three, by the way...)

The AW4 is mechanically the sam up to 1995 that I am certain of, and I think it stayed the same up to at least 1999. Like I said, according to Hollander's it should work.

If you are worried, move the transfer case over with the transmission and reuse the driveshafts, that will work. I swap driveshafts around between my XJ's all the time (AW4/231, BA-10/231, AW4-242...)

5-90

[SimpleXJ]

Thanks for the help, 5-90. The 242 in mine is in a laredo, but good to hear it will work. I'm not worried about electronics, I can swap those off the old one. I was just wondering if the output shaft is the same for the 231 and 242. Guess you're right about swapping the t-case with the trans. I might have to do that.

thanks again

[5-90]

Don't hold me to this yet, but I think all the AW4's 1991-up used the same output. I want to recall there's some variation with the 1987-1990AW4, but that could be me getting wires crossed...

What's going to happen to the leftovers?

5-90

[Yucca-Man]

Don't hold me to this yet, but I think all the AW4's 1991-up used the same output. I want to recall there's some variation with the 1987-1990AW4, but that could be me getting wires crossed...That's how I understood it as well. The 91+ had the 23-spline output while earlier versions had 21-spline output, necessitating a difference in t-case inputs.

[JeepSpeedRacer]

The spline count:

As I understand it, the spline count is determined by the engine the unit is attached to, not the year.

Thus:
87-01 w/2.5 litre: 21 spline transmission/transfer case.
87-01 w/4.0 litre: 23 spline transmission/transfer case.
84-87 ???

FWIW: I'm about to install an NP231 from a 1989 4.0 A/T into a 1998 4.0 A/T which was originally equipped with an NP242.

[Digger87xj]

The spline count:

As I understand it, the spline count is determined by the engine the unit is attached to, not the year.

Thus:
87-01 w/2.5 litre: 21 spline transmission/transfer case.
87-01 w/4.0 litre: 23 spline transmission/transfer case.
84-87 ???

FWIW: I'm about to install an NP231 from a 1989 4.0 A/T into a 1998 4.0 A/T which was originally equipped with an NP242.
84 to 90 had 21 splines, m/t or auto
the 89 231 WILL NOT spline to a 98

[SimpleXJ]

Ok, thanks for the help guys. Glad to see it will work.

5-90, PM me about the "leftovers", I may be able to help.

Thanks again all.

SimpleXJ

[rust bucket xj]

the 91s of early production had 21 splines.... just to let ya know

[JeepSpeedRacer]

Sadly, you have been proven correct, and I have been proven to be an idiot!

So, next question: Can the input shaft from the 1989 NP231 be swapped with the input shaft from the 1998 NP242 To make the units compatible?

Signed,
Humbled Moron

[old_man]

Here is a good place to start your quest


http://www.novak-adapt.com/knowledge/np231.htm
Google is your friend.

[JeepSpeedRacer]

Here is a good place to start your quest


http://www.novak-adapt.com/knowledge/np231.htm
Google is your friend.

Thanks. I got the good news/bad news from a very helpful person (Jim) at AdvanceAdapters. The 21 spline AW4 will be a boat anchor this summer.