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4L80E/4.0

2stix

NAXJA Forum User
Location
fallbrook Ca.
ive heard of a few V8 swaps into XJs, but i was thinking a differant route here. has anyone swaped a 4L80e into a 4.0 XJ ? the AW4/np242 in my XJ has alot of miles and makes a whining noise any time in gear, and instead of rebuilding it, or getting another one, i was thinking about swapping in a new 4L80E and BW1370 that i allready have. i even have the drive shafts from the 1 ton duelly it was in, so only the axle ends would need fabrication. plus it is a fixed yoke on the BW1370. seems like a pretty nice upgrade to me. what do you guys think?
 
honestly i have not yet touched this jeep. it was dads and i did tell him to have the tranny serviced. he said he did, but i dont know what they did, full flush, or just fluid change, ect. the jeep is my project now and will start working on it in a few weeks. we are having our fist baby any day so everything has been on hold. yes the AW4 might be better after the flush and fluid change, but it still has over 240K miles on it. i have the almost brand new 4L80E/1370 and feel the upgrade would be nice to have. just trying to get some info on the possible upgrade.
 
Well, it's your Heep, time and money so more power to ya! But I've heard of Jeeps going a lot longer than 240k, so I was just throwing that out there. Plus, you have a baby coming soon, so time/money may come into play...but that's for you to decide.

Since I cannot be of any help with what you're asking, I wish you good luck...let us know how it comes out!
 
The 4L80E is huge. Its ran off a computer, and you'd have to wire it into the chrysler electronics. What are you going to use for a Tcase? Driveshafts will have to be lengthened and shortened. Does any company even make a bellhousing to bolt up to the 4.0 and 4L80E?

For the cost of things, time fabbing, and figuring out all the other stuff, hit the junkyard and get another AW4.
 
joshv98xj said:
I'd love to know what it is you're thinking about- but I don't know the lingo. What is the "4L80E/1370" combo you're talking about out of?

The "4L80E" is a General Motors slushbox, four-speed, fairly heavy-duty (4 means four speeds, "L" means longitudinal mounting, 80 is the "duty rating," for lack of a better term. The "E" suffix means electronic control - CanMan is right, you'll need either a separate computer to run the transmission, or something similar to BrettM's AW4 manual controller.) The "1370" is probably the Borg/Warner 1370 transfer case - which is also fairly robust. However, I think the 4WD 4L80E has the standard Dana 300/NV mounting pattern, so you can probably just match up the spline count (no, I haven't found out what it is, offhand. Yet...)

The AMC242 uses the same bellhousing pattern as the AMC150ci four-cylinder, which was pulled from the GM "metric V6" pattern on the backside of the 2.8L 60-degree V6. So, it's a GM pattern - but I don't know if the 4L80E can be had using the same pattern. It's designed to go behind rather large engines - like Small Blocks - so it may use the SBChevvy mounting pattern. You should be able to find an adapter plate, however, if nothing else - check with Advance Adapters and Novak for a jumping-off point.

Also, where does the starter motor mount for the 4L80E? Just wondering...
 
first off, this is just a thought so dont get too wild. advance adapters makes the adapter and from what ive read so far isnt that expensive. the stand alone computer control is expensive however so id probably go with the transgo shift kit that makes the 4l80e full manual, but deletes all electronics, its about $250. (this is basically a trail rig only). starter doesnt mount to the trans, it mounts to the block. so if the starter on the AW4 mounts to the bellhousing, well then this idea is scrapped allready. guys im just thinking of stuff and trying to calm myself right now. so none of this is a priority type thing. im just playing with some ideas. and i do appreciate all your comments. thanks.
 
2stix said:
first off, this is just a thought so dont get too wild. advance adapters makes the adapter and from what ive read so far isnt that expensive. the stand alone computer control is expensive however so id probably go with the transgo shift kit that makes the 4l80e full manual, but deletes all electronics, its about $250. (this is basically a trail rig only). starter doesnt mount to the trans, it mounts to the block. so if the starter on the AW4 mounts to the bellhousing, well then this idea is scrapped allready. guys im just thinking of stuff and trying to calm myself right now. so none of this is a priority type thing. im just playing with some ideas. and i do appreciate all your comments. thanks.

The starter typically mounts to both the bellhousing and the engine (on the 242, you have one screw coming from the engine side to thread into the bellhousing, and one from the transmission side to thread into the starter nose housing.) Also, there has to be a "pocket" on the bellhousing for the starter nose - or you're going to have to make one, or the starter will "self-clearance" if the nose housing doesn't give out first.

The SB Chevvy and derived engines have pads on the block for the starter to mount to, but there will still be a "pocket" on the bellhousing for the starter nose - this is why you can't switch out the front-wheel-drive V6 for the rear-wheel-drive - the starter nose "pocket" will be on the opposite side of the engine from the starter motor mounting pad. So, it's still something you have to bear in mind.

I figured you're playing with ideas - and I applaud that! I just wasn't sure you were aware of the things that I was, so I thought I'd pass them along (now, you tell me what you know - and we'll both know more:dunno: )
 
The 4.0 uses the AMC general bellhousing pattern which is shared with all AMC engines...the 4L80 is pretty stout, basically a modified TH400 with overdrive and a lock up converter, electronically controlled.

I know a couple of companies sell adapters to mate the 4.0 to a TH350 or TH400.....but the swap would be horribly expensive from most prespectives if you factor in the control nightmare. And I have no idea how the TC snout would mate up to the 4.0 crank or how the flexplate could be made to hook up (obviously this has been worked out for the 350 and 400 but I haven't seen a 4L80 out of a vehicle yet so I dont know if there are physical differences)....and Jon raises the question about starters...not exactly a fun saturday of wrenching.

But the AW-4 is a very stout trans in it's own right, capable of handling 300+hp in stock trim. Modified versions such as used in turbo Supras handle even more.

If it was me, I would find a good used tranny and swap em out.
 
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