98 AW-4 into 90 XJ

J

jlake1

NAXJA Forum User

Location

Michigan

• Dec 3, 2003

• #1

Just picked up a 98 AW-4 from Davey to replace the 21sp unit in my 90 XJ.

Hey gave me the TCU and all the connections for the new(er) tranny.

My question is, can I simply swap in all the new components and fire it up, or is there some splicing to be done?

Thanks,
Jay

 

J

jlake1

NAXJA Forum User

Location

Michigan

• Dec 4, 2003

• #2

BTT...

Some one's done this, right?

 

Eagle

Lifetime NAXJA Member

NAXJA Member

Location

Terra Firma

• Dec 4, 2003

• #3

The 98 has a 23-spline output to mate with the transfer case.

I'm not sure when the change took place, but your '90 might have a 21-spine output.

 

J

JBrobeck

NAXJA Forum User

Location

Cottage Grove MN

• Dec 4, 2003

• #4

Correct me If I'm wrong, but I thought the TCU was integrated into the ECM in the latter years, your 90 has a seperate TCU and a seperate Engine computer doesn't it??

 

L

lunghd

NAXJA Forum User

Location

New River Valley, VA

• Dec 4, 2003

• #5

Yup, 90 (non-HO) should be 21 spline & has a seperate TCU.
HO's should be 23 spline & integrated TCU.

 

L

lunghd

NAXJA Forum User

Location

New River Valley, VA

• Dec 4, 2003

• #6

lunghd said:

Yup, 90 (non-HO) should be 21 spline & has a seperate TCU.
HO's should be 23 spline & integrated TCU.

Click to expand...

I be correctin' meself - seperate TCU up to 95 at least (maybe up to 97 but I dunno). This from a guy on another forum who's 95 HO has one. I do not know if the TCU's interchange (probably not) from HO to Renix.

 

A

andyr354

NAXJA Forum User

Location

North Central KS

• Dec 4, 2003

• #7

Might have to change internal sensors and stuff from the older tranny to the new one. If it will work at all.

The 98 would have had the trans controlled by the engine computer. The older XJs the trans is controlled by a separate TCU on the backside of the pannel below the glove box.

Andy