TJ manual to auto tranny swap...

[blkTJ]

I'm looking for options and the pros and cons of each. I'd really like to get something with OD since my Jeep is my only vehicle and sometimes sees long road trips. Thoughts?

[JeepGal]

OHHHH NOOOO...turn away from the light, do not look at the light...the light is NOT friendly...WHY oh WHY would you want leave the DARK SIDE BRIAN?!?!?!?

Tam

[NAILER341]

wowzers! you are getting serious from what i hear, this is a pretty involved job. i think you know where you will get your best information on this topic... from those that have done it before

[blkTJ]

Originally posted by NAILER341
wowzers! you are getting serious from what i hear, this is a pretty involved job. i think you know where you will get your best information on this topic... from those that have done it before

yeah, I was just trying to get some info so I could post over there and not look like a total idiot. why start now. :yay:

[NAILER341]

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2438377262
chris, i think... did some research on this..
here is a link for a trans for you.. i am pretty sure that this is what you are looking for. great price too!

[Dukes69]

Goto Stu's site, he has an awesome write up on this. It looks like you need an AW4 trany, preferably from the same year XJ as your TJ. Make sure you get all the tranny wiring and the tranny PCM. Pedal assembly, shifter linkage and stuff. FSM for both vehicles will be helpful. One thing that really sucks about this is the wiring. The AW4, unlike the TF-999 that is put in TJ's, is an electronically controlled tranny. Not mechanical. So, you'll have to splice the tranny wiring into your TJ's wiring harness. The AW4 takes info from the TPS and other sensors to determine shift points, thats the reason for the splice. Now with that in mind, I was thinking to myself, "Hey Chris, what trannys are in Grand Cherokees?" I dont know, but maybe one of those woulf be easier to swap in . . . 42-RE I think they are called. Search on the BBS to see what has been posted before, and check out Stu's Site. Let me know what you find out. I really need an overdrive in my TJ. 4.88's and a 1:1 tranny ratio is killing me.

[igofshn]

In CA it is a major job because of the smog police. You will have to take your vehicle to a referee to get it to pass smog if you swap trannies.

[king4wd]

Personally, I prefer the manual on the freeway for the overdrive. However that is strictly a personal choice. As far as functionality goes autos have several advantages: they're easier to start on inclines, and they're almost stall proof. Manuals have one advantage, and its a big one: compression braking. The choice is yours, but like its been said: beware of the smog gestapos.

[blkTJ]

don't get me wrong. I love my manual, always have. It's just that I'm planning on taking my wheeling to the next level. All you have to do is make a few trips out to Johnson Valley and you'll understand. The advantages of the auto are evident in that type of extreme terrain. I'm just trying to figure out which auto to use. I don't really want to be stuck with a 3 speed and I'm not sure on the options for trannys with OD.

Anyone know anything about Dodge truck trannys? I know the Dakota uses the 231 TC. I wonder if the auto is the AW4.:confused:

[cbremer]

while searching for AW-4s, you may also be interested to know that some earlier ZJ's with the I6 also used the AW-4, which is the same thing as is the Toyota Tacoma's A340F. Supposedly, the Volvo 960's 30-40LE and Toyota Supra's A341E are very similar (maybe just different spline counts, which could be remedied with the appropriate shaft swap(s)?)

The Dakota/Durango used a TF6 (Torqueflite I think :confused: ) up til 1988, then switched to the A500, but they apparently have the appropriate adapter to mate to the NP231. WJ's have 42RE (aka A500) 4-speed (with the 6-cyl) or 45RFE 4-speed/545RFE 5-speed (with 4.7L V8) automatic transmissions. The 45RFE/545RFE, as far as I can tell, are a Jeep/Daimler-Chrysler design built in Indiana.

The newest (2003/2004) TJs and KJs (and Durangos!) have the 42RLE 4-speed auto (hint, hint) which might be an easier swap since you *probably* wouldn't have to splice in a separate transmission control unit (TCU)- i'd imagine that you may need a new engine computer however. Also, the smog Gestapo might be more lenient, since the donor vehicle is newer than the recipient, which is part of their criteria for engine swaps. but what do I know

*whew* got that?

[blkTJ]

wow chuck. impressive, very impressive.

My understanding (from the boss over at that other forum) is that the problem with a 42RLE is that it's just to darn big to use with a belly up skid.

After reading the write up on stu's page about the AW4 the wiring seems pretty intimidating. I suppose if you went through it step by step it wouldn't be too bad.

My new question concerns the TF6 or the A500. Are they computer controlled like the AW4? Seems to me that if you could find a 4speed that was mechanical the install would be tons easier.

[cbremer]

google is my friend

guessing here, but i'd figure that the TF6 was vacuum-controlled, then in 1989 they went to the computer controlled A500. Chris would know more about the Mopar trannys than I do, that's for sure

as far as using a mechanical or vacuum controlled tranny, the problem is that the TCU or engine computer (whichever is appropriate) is expecting input from the transmission (shifter position, torque convertor lockup state, whaich gear is currently engaged, etc.), as well as sending commands to it, such as when to shift gears or unlock the torque convertor.

how much clearance is needed with the 42RLE? would say... 1" motor mounts give enough clearance? how about 1.5" or 2" motor mounts and a 1" body lift? or is the tranny tunnel the problem? the tranny tunnel could always be "enlarged" with a BFH i'll have to read your other thread

[blkTJ]

there's no "other thread" yet. We were talking about it a few weeks back when I rode along on a hammers trip.

Seems to me the whole thing adds up to a big pain in the a$$. Not sure if I'll ever do it. The atlas is looking a lot more attractive.

I just ordered a 1" BL, 1" MML, belly skid and anti rock from Currie. Of course everything but the anti rock will sit around collecting dust until I make a descision on my drivetrain and go to 35s.

[igofshn]

You will definately love the Antirock.

[RatherBeJeeping]

Why not follow Seth's lead and do the 700R4?
Better first gear, not computer controlled, nice overdrive, tons of aftermarket support.