Estimates for 4 speed auto swap

[rang-a-stang]

My planning starts for a trans swap in a year'ish from now. Looking for high level comments and opinions.

I would like to stick an automatic 4 speed behind my 401. I don't want to change axles (passenger drop). I will be GM TBI by then (running either a 7747 or 7427 computer that can control the trans/Lock up on a 700R4/4L60/4L60E).

I read this thread:

http://www.ifsja.org/forums/vb/showthread.php?t=127576

First solution:
AMC V8 to 700R4/4L60/4L60E Trans adapter (~$450 for adapter and flexplate), then trans to QT case adapter (~$525) plus the other regular odds and ends of the swap (trans cooler, lines, fluid, trans temp gauge, trans, etc.). I would estimate this option to be about $1500 out the door if I buy a wrecking yard trans.
Pros: Easiest, least amount of work, great trans with good support,
Cons: $1000 in adapters

Second solution:
AW4 will bolt to my 401 but I am not sure if there are passenger side drop cases I can use, or if they will require new Drive shafts, speedo, crossmember, etc. I do not see a AW4 to QT adapter. I estimate about $1200
Pros: No engine adapter needed, hopefully a better case can be used
Cons: May need a separate controller, May need to make new drive shafts, needs a new Transfer case

Third solution:
AMC V8 to 700R4/4L60/4L60E Trans adapter (~$450 for adapter and flexplate), NP241 with passenger drop (~$200) plus the other regular odds and ends of the swap (trans cooler, lines, fluid, trans, etc.). I would estimate this option to be about $1500 out the door if I buy a wrecking yard trans and case
Pros: Great trans with good support,
Cons: May need new drive shafts, Passenger side drop 241s don't seem very easy/cheap to find, may need new speedo,

Other solutions?

I am not looking so much to hear which trans/case is better than the other or why. More like, which trans/case swap option is the most cost effective. I do 99.7% street driving, have 32" tires, and will never build insane horsepower (I doubt my 401 will ever make more than 300HP). When I do offroad, I do pretty light stuff. I am looking for a reliable, capable 4 speed auto (lock up would be nice, too), and 4WD. I don't want to hack my floors, I don't want to hack my dash.

What say you guys?

[joe]

Guessing you're hoping for better mpgs? What's your axle gearing? If it's not 3.54 or deeper the trans will constantly be hunting and shifting/staying in-to HI(3rd) so no gain by having an OD. The AW4 IMHO is a very good AT. Had two in XJ's current one has 155,000 on it and still works great. No idea what's involved lashing one up to a FSJ? FWIW mine have/had np231's(?) part-time tcases behind them and are drivers side drop.

Looking for high level comments and opinions

Can't help with that but suspect regardless of what you choose you'll be into it for a couple grand or more. You can buy a lot of fuel for $2000.

[ZackN920]

+1 for the AW4. My XJ has one, it has 180K on it and dirty fluid that I'm afraid to change.(heard some horror stories about if it hadn't been changed much, some autos are known to start slipping after new fluid)
That tranny shifts great, and I'm not too soft on it.

I got a Suburban with the TBI 350 and the 4L60E in it that's at 150K. It's solid, but I haven't heard of those transmissions making it as long as the AW4's. Maybe its because it shift's softer until you get down on it, idk... On average, i've heard of a range in the upper 200K's is about how long they last, if takin' care of. I know a few people, and family that have needed there's rebuilt, and they were usually around 280K.
My only gripe about it is that it does hunt some, if on a hilly highway. Not sure if I can do something about that, or if its how the pcm is programed.
I'd really like to modify that set up some, but I have no clue how to work with the fuel injection to actually make things work well/better.

[80Limited]

I second the AW4. Nice transmission, no quarrels here. Drove it daily in my Wagoneer for four months. I did a fluid and filter change in mine before I swapped it in with over 200k no crud in the pan no slipping. I don?t know if your opposed to a Dana 300, looks like Novak makes a clocking ring for the AW4 so you can use a passenger drop t-case. If you need help wiring it let me know.

[rang-a-stang]

Honestly, I am not sold on either trans. It all comes down to cost and ease of installation because I know either trans will meet my requirements as far as functionality and reliability. I am not opposed to D300 as long as I can get it under my truck without hacking my floors/crossmember. I will do searches for both transmissions on this forum and see how many builds I can find with either trans to get a good idea of what is involved in each.

[addicted]

Dodge NP208 '93 and older trucks. It should bolt right up to the AW4. The AW4 is a great trans and they are cheap to pick up. Anything other than what you have will require crossmember work and driveshaft mods.

[wiley-moeracing]

Will that aw4 hold up to the power of a 401?

[Mikel]

Will that aw4 hold up to the power of a 401?

A smogger 401 makes about the same power as a HO 4.0.

[mwood65]

This thread got derailed faster than an Amtrak train.......

[babywag]

I really don't understand why in 2018 people continue to treat the 401 as some sort of 4 cylinder economy engine.

A stock smogger 401 makes at least 215hp and 320ft-lbs of torque NET with retarded timing adjustments. Now care to state the numbers of the HO 4.0, or should I?

It was a smogger, and hardly a mythical unicorn.
Modern engines will spank it, so yeah people think it's what it was, a smogger.
I think you're missing Mikel's point that a modern smaller engine like the 4.0 makes similar power. As will other modern smaller engines.

For the OP though, an AW4 will likely be fine, and probably cheaper than a 4l60E swap initially?
I have debated a swap for a while now, I'm leaning towards the 4l60e myself.
Mostly due to the fact that my pcm will control it without a separate standalone controller like the AW4 uses.
BUT the AW4 not needing an adapter would significantly reduce the costs of a swap...so I waffle waffle waffle

[77Deepj20]

The aw4 would make the most sense.
For the transfer case, the np208 is common from 80's Dodge trucks and the np241 was also available in the dodge trucks up until 1993 with the passenger side drop.
Picked up a 241 for 100$ a little while back, a little harder to find but it's a better setup.

Just way too many adapters needed for a 700r4/4l60e for no real gain.

[ZackN920]

.80578hp per cubic inch on 4.0

.53615hp per cubic inch on 6.6 (401)



Hey Rang, Why do you want to put a 4 speed auto in for anyway? I dont see it really being worth it. I liked the idea before, but after some thought theres not much of a point unless it's your daily driver and you put a whole crap load of miles on it every year. Otherwise, not worth it for the extra mileage. The main benefit that I could see would be faster lower speed acceleration. After you put an overdrive trans in, it's best to change the axle gear ratios to use it better to your advantage, and with higher gears you can take off from a stop faster. But, with the overdrive you don't loose lower cruising rpm's on the highway, where if you did that with a 3 speed auto, you'll be running higher rpms on the highway.

[rang-a-stang]

The wife and I want to do long distance trips in my Cherokee. Like SoCal to Portland, then across to Boise/Pocatello, down to Provo Utah, then home. At 65 my engine is hummin and it just feels like it needs that extra gear.

I think between the Edelbroke intake, headers, and TBI I should have plenty of torque to cruise in 4th gear at 70MPH without hunting. I may also do an RV cam when I do those installs. I appreciate ALLL the chatter here; even the 4.0 vs. 401.

I don't really beat on my rigs (that's what rental cars are for) so I am not too worried if AW4 will hold up; I am sure it will. As I look around for service and upgrade parts though, I don't see much.
Deep pan; GM Trans=TONS of options, AW4=not so much
Torque converter options: GM=TONS of options, AW4=not so much
Online tech support (experience working on/fixing) GM Trans=EVERYWHERE, AW4=not so much
I am still not saying I am not going to do AW4, its just leaning toward GM because of supportability. I love that every time I have an issue with my TH400, EVERYTHING I ever wanted to know about this trans is on youtube. EVERYTHING. it looks the same for 700R4 and 4L60. there is good info for AW4 but not like there is for these GM trans.

I am finding yes, GM trans' need expensive adapters but that cost lets me keep my case and drive shafts. AW4 I have to change cases and driveshafts. Xfer Case+2 Drive shafts+speedo adapter+controller=GM Trans adapters. So total cost wise, it seems almost awash.

[babywag]

With intake/headers/efi you’ll definitely notice improvements.
My ‘90 has an RV cam, night vs. day in how the engine pulls.
The ‘79 my dad bought(258) got an RV cam, again HUGE difference.
Cheap hp and worth it imho.

I lean more towards the 4l60e, but I would never pay $ to keep a QT.
They’re all old & worn, parts cost too much...if even available.
I loved the QT when I was younger, no better case in snow!!
Could plow through drifts over hood, yank buddies outta ditch, they just worked.
Fast forward decades...nope, won’t run one.
last one i owned was a horror show inside!
bought a th400/d20 combo out of commando.

I’d spend $4-500 for driver drop front axle vs. an adapter to keep a QT!
just my .02
either trans. will get job done, each has pros/cons.
definitely more aftermarket support w/ 4l60e

[Cecil14]

The AW4 will hold up to anything and everything just about anyone on this forum is likely to throw at one. Discounting some of the obvious extremes, they're a seriously solid transmission. Tons and tons and tons of people running strokers in front of AW4s with no problems.

The AW4 uses a standalone computer in the XJs (at least the OBDI era), but you still need the input from the couple various sensors, TPS and VSS at least? Not sure how the GM sensors will play with the AW4 controller?


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