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-   -   5 speed auto trans in xj? (https://www.cherokeeforum.com/f67/5-speed-auto-trans-xj-149512/)

Gade91 09-22-2012 02:22 AM

5 speed auto trans in xj?
 
I've been doing some research trying to figure of what I'm going to swap in for my transmission (currently have a Peugeot ) and I'd like to go to an automatic. I want to retain my mpg's so Ive been lookin for a 5 or 6 speed trans to put in but can't find any that will work, is there anybody that has heard of any or has any idea on this?

NorCalJeep 09-22-2012 02:27 AM

The only auto trans i know of that fits the XJ is the AW4.

Power73 09-22-2012 04:15 AM

X2 the aw4 would be the easiest

5-90 09-22-2012 05:38 AM

The AW4 will work, but requires electronic controls (grab from donor, figure out integration from the FSM.)

If you go with earlier full-size Jeeps, you can find the A727 or THM400 (both three-speed) with the AMC bellhousing pattern, but the THM400 will require its own BorgWarner transfer case. I don't recall what the A727 used, but I think it was a standard item. However, neither of these are electronically-controlled, it's line pressure and hydraulics (plus maybe a vacuum modulator.) Both of these should be behind V8s - most probably the A360 or A401.

Going with a five-speed or a six-speed will definitely require electronic controls (like a 5-45RFE or maybe a 6L80?) but you're also going to require an adapter plate - the problem with Jeep is that they used AMC engines since the late 1960's, and the AMC bell isn't directly compatible with anything else. I do believe Novak Adapters can help you with an adapter plate, but you're pretty much on your own for electronics (I'd probably be tempted to bypass everything but the shift function and do a "manumatic" shifter by tripping the shift control solenoids in sequence - you'll need a truth table for that, and it will essentially be a "clutchless manual" unless you figure out how to make the "Drive" control work.

Given a choice, I'd probably go with a GM box. Adapter plates should be easier to find, and GM is usually easier to cobble controls for. The 6L80 has ratios of 4.027/2.364/1.532/1.152/0.852/0.667-3.064 (double overdrive, no direct drive - but most of these five-speed or six-speed slushboxen tend to have two overdrive ranges,) tips the scale at somewhere just over 200# (most versions,) and uses a 300m/m diameter torque converter (which should fit, but you'll have to work out the flexplate on your own.) Figure this started to appear about 2006 or so. 4WD versions should be available.

Yeah, you can find the 5-45RFE in a Jeep application (V8 WJ/WK,) but it wasn't behind a Jeep engine, so the bellhousing will be wrong. I don't know if the later "Pentastar" engines still used the LA-block bellhousing pattern, so I can't really give any advice there. I'm still developing that information myself...

93XJLI 09-22-2012 08:33 AM

There is no reason not to use the AW4. You won't get better economy even if you managed to get the new ZF 9 spd behind the dart working in your jeep.

Gade91 09-25-2012 10:44 PM

Why wouldn't it matter? I mean I know that the more gears you have will help with mpg

Willys55 09-25-2012 10:50 PM


Originally Posted by 5-90 (Post 2036510)
The AW4 will work, but requires electronic controls (grab from donor, figure out integration from the FSM.)

If you go with earlier full-size Jeeps, you can find the A727 or THM400 (both three-speed) with the AMC bellhousing pattern, but the THM400 will require its own BorgWarner transfer case. I don't recall what the A727 used, but I think it was a standard item. However, neither of these are electronically-controlled, it's line pressure and hydraulics (plus maybe a vacuum modulator.) Both of these should be behind V8s - most probably the A360 or A401.

Going with a five-speed or a six-speed will definitely require electronic controls (like a 5-45RFE or maybe a 6L80?) but you're also going to require an adapter plate - the problem with Jeep is that they used AMC engines since the late 1960's, and the AMC bell isn't directly compatible with anything else. I do believe Novak Adapters can help you with an adapter plate, but you're pretty much on your own for electronics (I'd probably be tempted to bypass everything but the shift function and do a "manumatic" shifter by tripping the shift control solenoids in sequence - you'll need a truth table for that, and it will essentially be a "clutchless manual" unless you figure out how to make the "Drive" control work.

Given a choice, I'd probably go with a GM box. Adapter plates should be easier to find, and GM is usually easier to cobble controls for. The 6L80 has ratios of 4.027/2.364/1.532/1.152/0.852/0.667-3.064 (double overdrive, no direct drive - but most of these five-speed or six-speed slushboxen tend to have two overdrive ranges,) tips the scale at somewhere just over 200# (most versions,) and uses a 300m/m diameter torque converter (which should fit, but you'll have to work out the flexplate on your own.) Figure this started to appear about 2006 or so. 4WD versions should be available.

Yeah, you can find the 5-45RFE in a Jeep application (V8 WJ/WK,) but it wasn't behind a Jeep engine, so the bellhousing will be wrong. I don't know if the later "Pentastar" engines still used the LA-block bellhousing pattern, so I can't really give any advice there. I'm still developing that information myself...

seriously? party pooper

mrfajita 09-26-2012 03:57 AM


Originally Posted by Gade91 (Post 2043614)
Why wouldn't it matter? I mean I know that the more gears you have will help with mpg

Its not the number of gears, its how you use them, and with a few custom wiring tricks you can run an AW4 like an 8 speed (1-2 lockout switch and TC lock-unlock switch)
Though its more effort than its worth. Just keep the Aisin, its more reliable than a chrysler slushbox even if its inefficient and runs at 260 degrees on a regular day.

93XJLI 09-26-2012 08:02 AM

My aw4 runs at 120 all day. I guess yours sucks.

5-90 09-26-2012 10:02 PM


Originally Posted by Willys55 (Post 2043631)
seriously? party pooper

I call 'em like I see 'em - and if I don't see 'em, I make 'em up!

As far as AW4 heat - it's not a big problem. I recall towing a 17,000# load in my 87 (6-242/AW4/NP231/D30/D35 3.55:1) about forty miles once - boss had the work truck, and I loaded the machine on the trailer very carefully! to get it back to the shop for repair, and it stayed under 215*F the whole way.

Granted, I topped out at about 35-40mph - but if something is going to heat up a sluhsbox, overloading it with a tow is guaranteed to be it!

And this was with the OEM cooler - I hadn't installed the external yet!

If you're consistently running that hot, check for slipping clutches or a failure of the TCC lockup, because that's probably where it is.

mrfajita 09-26-2012 10:14 PM

Mine doesn't run 260, I don't have a temp gauge, but I have heard of them running that hot. Kinda want to put one in but never got around to it.


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