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Spline issues


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Well, it appears that I will have to replace/rebuild an AW4 transmission soon. I have access to a 1996 2WD AW4 with about 100K on the clock. The fluid looks good and the only problem is I am confused about the spline issue.

 

I have been told this particular transmission has a 21 spline shaft. (I am assuming the spline count is on the shaft that is on the engine side of the transmission).

 

Does anyone have a listing of what spline counts went in what years? I have been told that the AW4 was used in the XJ and MJ from 1987 until 2001 but are they all the same spline count? If not, why would some be different?

 

As the vehicle is currently moving but leaking, I'd rather not pull the existing one yet and disable the thing just to count how many splines the existing transmission has.

 

Thanks in advance

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From what I know, all the input shaft spline counts for the Torque converter are the same. Generally when spline count is referred, it's for output to the T-case or, in 2wd cases, the driveshaft. At some point around 1990 the output on the 4wd ones changed from 21 to 23, but I don't know about the 2wd ones. I know my 91 2wd AX-4 has a 21 spline output.

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From what I know, all the input shaft spline counts for the Torque converter are the same. Generally when spline count is referred, it's for output to the T-case or, in 2wd cases, the driveshaft. At some point around 1990 the output on the 4wd ones changed from 21 to 23, but I don't know about the 2wd ones. I know my 91 2wd AX-4 has a 21 spline output.

 

I had to edit my first post...the used one I can buy is from a 2WD XJ, and would be going into a 2WD XJ. They have another that is currently mounted in a 4WD XJ but they do not know the count on that one.

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Ok, here goes:

 

The daughter's XJ is a 94 2WD, and the AW4 that is currently out of the donor is a 96 AW4 - the donor vehicle was a 2WD. I am going to look at this unit today.

 

The second donor still has the AW4 installed, it is an 89 4WD XJ.

 

Don - thanks for your post but it kinda points out my question....is there any way to tell the output spline count without actually removing the transmission? I know they have ID plates on them, but of course it is mounted in a hard to see place :roll:

 

Thanks

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they should all be the same (27 spline), but you can always drop the driveshaft and count them. Better yet, drop the shaft and take the slip yoke (or the whole thing even) with you when you go to look at the new unit. If the slip yoke slides onto the splines, you know they are the same.

 

Jeff

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You need to clarify what you are trying to do. You keep referring to 2WD and 4WD AW4s, which have major differences. At this point it is far from clear what you want to do.

 

Do you want to replace a 2WD AW4 with a 2WD AW4?

 

Do you want to convert a 2WD XJ to 4WD?

 

Willy

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You need to clarify what you are trying to do. You keep referring to 2WD and 4WD AW4s, which have major differences. At this point it is far from clear what you want to do.

 

Do you want to replace a 2WD AW4 with a 2WD AW4?

 

Do you want to convert a 2WD XJ to 4WD?

 

Willy

 

I apologize - my only reason for mentioning the 4WD tranmission was because they have one and I didn't know if it made a difference (in the spline count).

 

I am going to go from a 2WD AW4 to the same. I just seem to keep seeing references to various spline counts and wanted to see if there was a quick and dirty (pardon the pun) way of making sure I was buying the right one.

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If you are not converting to 4WD, then don't even consider the 4WD AW4. You need to get a 2WD AW4 to replace you current 2WD AW4.

 

As for the output spline count of a 2WD AW4, it is fairly easy to remove the driveshaft and count the splines. You don't need to remove the transmission and that will be the most definitive way of determining if it matches the spline count of your current transmission. :thumbsup:

 

Willy

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As the vehicle is currently moving but leaking, I'd rather not pull the existing one yet and disable the thing just to count how many splines the existing transmission has.

 

Where is it leaking from? Is the case cracked?

 

Willy

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As the vehicle is currently moving but leaking, I'd rather not pull the existing one yet and disable the thing just to count how many splines the existing transmission has.

 

Where is it leaking from? Is the case cracked?

 

Willy

 

I cannot tell where the fluid is coming from. I have douched the underbody clean of oil and still can't tell. All I know is that I have to add two quarts of trans fluid a month.

 

The case is not cracked, as far as I can tell.

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The major difference between the 2WD and 4WD AW4's is that the 2WD version has uses a tail shaft extension for final output to the drive shaft; the 4WD uses a 4WD adapter for final output to the t-case. The 2WD tail shaft extension (p/n 83504046) was sold as a unit assembly and included the output shaft. All the 86-96 MJ/XJ 2WD's w. the AW4 used this same extension. Sooo, it can be very safely ASSumed that 86-96 output shafts are the same - 27 spline. :D

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As the vehicle is currently moving but leaking, I'd rather not pull the existing one yet and disable the thing just to count how many splines the existing transmission has.

 

Where is it leaking from? Is the case cracked?

 

Willy

 

I cannot tell where the fluid is coming from. I have douched the underbody clean of oil and still can't tell. All I know is that I have to add two quarts of trans fluid a month.

 

The case is not cracked, as far as I can tell.

 

It would probably be a good idea to find the source of the leak before jumping to completely replacing it. It is likely just a seal that can be found for a few dollars that needs to be replaced.

 

First place I would check is the transmission input seal. It is easy to remove the access cover on the bottom of the bell housing. If there is transmission fluid in there, most likely the seal has gone bad. For me this goes bad pretty regularly. I have replaced it on two of the four driving XJs/MJs I've owned. The most recent I replaced before I put the transmission in because I knew I would need to do it eventually.

 

Willy

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Yeah, I plan on looking over the existing one before I make the decision to pull it, and repairing/replacing seals if they appear to be the culprit. The other problem is the fluid that remains is brown and burnt smelling as well... :roll:

 

I also remembered (when I was trying to sleep last night) that I recently replaced the radiator and need to check the cooling line connections.

 

I looked at the JR AW4 yesterday and it has pink fluid and no apparent leaks. Best part...he's selling it for $100.00 with the cables, slip yolk, NSS, and torque converter/bell housing. I believe even if I don't use it it's still a good deal just for the parts

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