Is there a better direct replacement for a 42RLE in a 06 Rubicon?

99wranglersport · Jul 27, 2018

I have a 2006 Jeep Rubicon Unlimited with an 42RLE transmission. Its been acting weird in the past but after our Colorado trip and driving over Monarch Pass it got much worse. It sometimes goes into neutral when idling in gear and bumps into first after throttling up. Sometimes it takes off in second or third gear from a stop. It may can be fixed but I'm curious if there is a better transmission that would bolt right in without too much modification. I'm not a fan of the far apart gear ratios in the transmission anyway. This is a street legal regular driven vehicle with a small lift and 35's on it as of now and will probably get 37's in the future. Any advice is much appreciated.

Big David · Jul 28, 2018

The AW4 is a tough transmission & has been swapped into many TJ's.

felipecj · Jul 28, 2018

The AW4 is also a 4 spd with overdrive right? Or 3 spd with overdrive?

99wranglersport · Jul 28, 2018

What vehicles did the AW4 originally come in?

mdo817 · Jul 29, 2018

99wranglersport said:
What vehicles did the AW4 originally come in?

Jeep XJ Cherokee

99wranglersport · Jul 29, 2018

I'm gonna see if mine is repairable without a total rebuild. If not, I'll keep a look out for the AW4. Thanks for the info.

Big David · Jul 30, 2018

felipecj said:
The AW4 is also a 4 spd with overdrive right? Or 3 spd with overdrive?

3 speed + OD

You will need a a '91 up to match the splines on the t case.

drivermod · Jul 30, 2018

I too had some issues with the 42RLE in my 05 Rubicon. Often times after running around in 4 low for a bit, it would shift weird when I went back to 2wd. For starters, try disconnecting the battery. This seemed to reset the shifting patterns. Workded for me every time I had shifting issues. I looked into alternative transmissions as well but as far as I could tell a swap wasn't going to be very straight forward. Starting in the 2005 Wranglers the transmission did not have a separate ECU from the engine which complicates things. I've read that up through 2004 Jeeps swapping to an AW4 isn't a big deal. The AW4 is a great transmission but do some research. May not be worth doing. I've since sworn off any Jeeps with the 42RLE.

jp fan · Jul 30, 2018

Big write up on Rubicon owner forum about it. They was talk about an updated computer for them. I was looking a awhile back from going from my 6 speed to a factory auto and with just a little reading I decided to stay with what I got

lt99ls1 · Jul 30, 2018

99wranglersport said:
I'm gonna see if mine is repairable without a total rebuild. If not, I'll keep a look out for the AW4. Thanks for the info.

I am running a AW4 in my 05 Rubicon.
You need to get your donor parts from a 98 to 01 XJ, Stay away from the 97s because they are a one off year.
Grab the transmission, tq converter, flywheel, transmission wiring harness,TCM from the XJ.Then pick up one of these from Hesco http://www.hesco.us/products/7902/40l-conversion-parts/45304/05-06-damper-kit-hes0506ed#.W18VwdJKiUk and your all set. I think it is five wires to splice the XJ TCM into the stock harness and it will shift like a dream.

drivermod · Jul 30, 2018

lt99ls1 said:
I am running a AW4 in my 05 Rubicon.
You need to get your donor parts from a 98 to 01 XJ, Stay away from the 97s because they are a one off year.
Grab the transmission, tq converter, flywheel, transmission wiring harness,TCM from the XJ.Then pick up one of these from Hesco http://www.hesco.us/products/7902/40l-conversion-parts/45304/05-06-damper-kit-hes0506ed#.W18VwdJKiUk and your all set. I think it is five wires to splice the XJ TCM into the stock harness and it will shift like a dream.

Great info. Wish I had discovered this when I still had my LJ. Will keep in mind for future reference.

drivermod · Jul 31, 2018

BTW, lt99ls1, was your rubi originally and auto or manual?

lt99ls1 · Jul 31, 2018

drivermod said:
BTW, lt99ls1, was your rubi originally and auto or manual?

It was a manual.

I forgot to say grab the shifter, shifter cable, transmission tunnel and shifter plate off the donor Xj also if you don't start with an auto.
The 97 to 02's don't have to have the Hesco balancer to do the swap.

This is the second TJ/LJ that I have swapped a AW4 into.

blacksheep10 · Jul 31, 2018

Good info, have an 04 rubi with tons/links and a manual I hate. Love to swap an auto but at that point maybe 5.3/is auto is better.

drivermod · Jul 31, 2018

lt99ls1 said:
It was a manual.

I think that was the rub when I was looking into it. Since I was starting with an 05 auto the swap was more complicated. Seems I recall that if I had a wiring harness from a manual Jeep it would be a fairly easy swap. Certainly possible that I didn't find the correct info though.

lt99ls1 · Aug 1, 2018

blacksheep10 said:
Good info, have an 04 rubi with tons/links and a manual I hate. Love to swap an auto but at that point maybe 5.3/is auto is better.

The 5.3\4l60 is better and alot more costly to do it right.

I have had my 5.3\4l60 setup sitting int he garage for about 16 months now while I slowly gather all the rest of the stuff to do the swap right.

blacksheep10 · Aug 1, 2018

Done her a few times, its time and motivation I'm lacking. Tcase is other big variable. I have a stak 2 speed, so an auto swap with current engine/trans goes right on. Go to GM stuff, find a new case and this thing IS NOT getting an atlas.

creepycrawly · Aug 1, 2018

blacksheep10 said:
Done her a few times, its time and motivation I'm lacking. Tcase is other big variable. I have a stak 2 speed, so an auto swap with current engine/trans goes right on. Go to GM stuff, find a new case and this thing IS NOT getting an atlas.

Off topic, but why aren't you a fan of the atlas?

blacksheep10 · Aug 1, 2018

creepycrawly said:
Off topic, but why aren't you a fan of the atlas?

$

Also $$

Only reason it has a stak is because that's what it came with. No desire to spend a boatload on this thing, I have a spare old 5.3, a couple harnesses and 2 4l60's that are just sitting on the shelf, I can do the swap as cheap as anyone with the stuff I have laying around, but I'm not dropping thousands on a tcase.
I had an Atlas in my buggy, worth it. I like the product, but for a jeep I'll eventually sell, totally not worth it as the money won't come back

Edit, I wish there were an affordable drivers drop solution for 3.0 gears in a 205. Even mid 2.xx's would work. I can put a ford 205 on the back of a 400/4L80, I've done it with no issue, just putting a 2.0 case in something on 40's and a 5.3 doens't pencil out, even with 5.13

creepycrawly · Aug 1, 2018

blacksheep10 said:
$

Also $$

Only reason it has a stak is because that's what it came with. No desire to spend a boatload on this thing, I have a spare old 5.3, a couple harnesses and 2 4l60's that are just sitting on the shelf, I can do the swap as cheap as anyone with the stuff I have laying around, but I'm not dropping thousands on a tcase.
I had an Atlas in my buggy, worth it. I like the product, but for a jeep I'll eventually sell, totally not worth it as the money won't come back

Edit, I wish there were an affordable drivers drop solution for 3.0 gears in a 205. Even mid 2.xx's would work. I can put a ford 205 on the back of a 400/4L80, I've done it with no issue, just putting a 2.0 case in something on 40's and a 5.3 doens't pencil out, even with 5.13

Totally makes sense. I read that differently and thought you had issues with the atlas and preferred the stak. Thanks for clarification.