Estimates for 4 speed auto swap

[PlasticBoob]

I'm going to split this off into a new thread so we don't keep polluting Rang-a-stang's...stay tuned.

[ZackN920]

The wife and I want to do long distance trips in my Cherokee. Like SoCal to Portland, then across to Boise/Pocatello, down to Prov 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.

You need a tach man. Find out what that engine is actually spinning at. You may find that its not turning as fast as you think. Or then again maybe it is. Find out what gears you have as well.
Now for me I think mine is around 2400 at 65. Not sure at the moment. I know it hangs around 2-2100 at 55. I've got 3.31 gears. Doesn't sound like its humming at all until around 70-75, and even then its not spinning to ungodly fast.

[TexasJ10]

I hadn't really thought about the AW4 before but you guys have me thinking about it. What do you use for a a flex plate on a 360? Are the sensors needed to run the computer something you can take off an xj? What axle ratios are used in stock form?

[Cecil14]

Crank bolt patterns and clocking are the same between the Gen3 V8s (304/360/401) and the Gen2?/3 I6s (232/258/4.0). You'll have to grab a flexplate for a 4.0 and have it match balanced to one for a 360.

As for the sensors: there was a post not too long ago about an aftermarket TPS that worked with the AW4, I think. There are VSS adapters, yes. Hesco has/had one that has both a mechanical cable hookup and a plug for the electronic one. I believe they just took that off an OBDI era XJ, though, and you can likely get it for about 10% of what Hesco wants.

Edit: these are not the thread I was thinking of, but they appear to cover the majority of the hurdles of the AW4 swap on a carbed vehicle:

http://www.ifsja.org/forums/vb/showthread.php?t=98429&page=9

http://theamcforum.com/forum/aw4-conversion-by-rick-sc397_topic15549.html

aa

[rang-a-stang]

... but I would never pay $ to keep a QT.
They?re all old & worn, parts cost too much...if even available.
Fast forward decades...nope, won?t run one.

I hear you. I just installed an almost brand new chain from blkilby, and bought a NOS E-Drive motor ($85). I hope to get a good 10 years out of this case. When it pukes, I'll sell it/part it out. It is part time at this point and I just don't see it wearing out. I have a spare set of bearings out of an old case I had lying around and the seals are easy to find. If I was still full time, I would be more worried.

I?d spend $4-500 for driver drop front axle vs. an adapter to keep a QT!
just my .02

FANTASTIC idea! Hm. I will keep my eyes open for one over the next year but being a WT makes it a little harder to find. I think the only year WT front axles with Driver drop would be 80-83 Cherokee and 80+ J truck, right?

You need a tach man. Find out what that engine is actually spinning at. You may find that its not turning as fast as you think. Or then again maybe it is. Find out what gears you have as well.
...

Concur. I have a tach sitting on my parts shelf waiting to go on. Its just a little low (but moving up quickly) on my priority list. Hopefully in the next 3 or 4 months I'll have it on my truck. I have the standard open 3.54's on my rig and my tires are only 10% taller than stock. When these tires wear out, I will go down a size because I don't want to change rims but these tires are just a bit too wide for my rims (I have 16x7's and am running 265/75-16s).

[Wagoneerlover]

Greetings,

Just adding to the thread. I swapped anAW-4 into my rig years ago. I used the original Np229 (needed a spacer) that came with my rig. (I didn't see that as one of the options you wanted.) I was able to retain my original column shifter and wiring up the controller (Stand alone) controller for the aw-4 is a piece of cake. I would seriously consider that option. As for mating it with a QT transfer case I cannot help you there but it can mate up with many of the np/nv transfer cases. (little work required on some, more on others.) They have clock ring adapters out there for other np transfer cases and you may have to open up the case and swap input gears. etc.) It can be done but you will have to do some research and if not mechanically inclined enough to do some of the things necessary, reach out to some of the members in your area with the skill to do it and order some beers and a couple of pizzas and go for it.

[TexasJ10]

Crank bolt patterns and clocking are the same between the Gen3 V8s (304/360/401) and the Gen2?/3 I6s (232/258/4.0). You'll have to grab a flexplate for a 4.0 and have it match balanced to one for a 360.

aa

I wonder how many places have the proper spin equipment to do this right? I think this is the one thing that bothers me the most about the AW4 swap. I couldn't find any pre made flexplates for this conversion and the number of places that still have the capability to properly rebuild an engine around here including having this equipment is getting pretty small.

[ZackN920]

Concur. I have a tach sitting on my parts shelf waiting to go on. Its just a little low (but moving up quickly) on my priority list. Hopefully in the next 3 or 4 months I'll have it on my truck. I have the standard open 3.54's on my rig and my tires are only 10% taller than stock. When these tires wear out, I will go down a size because I don't want to change rims but these tires are just a bit too wide for my rims (I have 16x7's and am running 265/75-16s).

You ever check out a speed to RPM calculator online? I looked up from your info. For your current size tires and differential ratio's, your around what us, with stock size tires(235-75/R15) and 3.31's, are at.

I found that at 55, you should be around 2077rpm's. At 70 you should be at around 2643rpm's. This is with the 1:1 gear in the trans(3rd).
You probably could benefit a little from an overdrive. Still not really high though, unless you plan to be doing 80+ consistently. Heck, even at 80 you'd only be spinning around 3K, but mpg's might really take a drop, the higher the engine is turning. I don't really know where best mileage would be attainable at, when it comes to consistent engine speed.


Huh, be glad your Jeep's not at bad as my Dodge. At 55 it's allready at 2409rpms, at 70 it's at 3065rpms. It could really benefit from an overdrive trans, but i plan on keeping the A999 that it's got.

[rang-a-stang]

...I swapped anAW-4 into my rig years ago. I used the original Np229 (needed a spacer) that came with my rig. (I didn't see that as one of the options you wanted.) I was able to retain my original column shifter and wiring up the controller (Stand alone) controller for the aw-4 is a piece of cake. I would seriously consider that option. As for mating it with a QT transfer case I cannot help you there but it can mate up with many of the np/nv transfer cases. (little work required on some, more on others.) They have clock ring adapters out there for other np transfer cases and you may have to open up the case and swap input gears. etc.) It can be done...

EXACTLY the type of data I am looking for! Thank you SOOo much for posting!

You ever check out a speed to RPM calculator online? I looked up from your info. For your current size tires and differential ratio's, your around what us, with stock size tires(235-75/R15) and 3.31's, are at.

I found that at 55, you should be around 2077rpm's. At 70 you should be at around 2643rpm's. This is with the 1:1 gear in the trans(3rd).
You probably could benefit a little from an overdrive. Still not really high though, unless you plan to be doing 80+ consistently. Heck, even at 80 you'd only be spinning around 3K, but mpg's might really take a drop, the higher the engine is turning. I don't really know where best mileage would be attainable at, when it comes to consistent engine speed.

Good gouge!

I am going to go out on a limb here (happy to hear some folks correct/disagree). I think a the value in a 4 speed is more than just the 4th gear. That extra gear means that the engine RPMs don't swing as wildly between gear changes as you drive around and therefor its in its more efficient RPM range more often. With an EFI engine, that all means less injector pulses and more efficiency. That 4 speed is not just our 1-3 with an added gear, its also lower first gear, slightly higher second, same third, then OD.

I would assume that a rig would see much more value out of a 4 speed if it is EFI'ed vs carb'ed.

[babywag]

You are correct. A 4spd auto is more than just a 4th gear and a lockup converter.

http://www.tciauto.com/tc/gear-ratios/

[yossarian19]

AW4 has a 2.80 first, 1.53 second and 1:1 third with most of them using a 0.75 OD
It was used in the Sequioa, with a rated gross vehicle / trailer weight around 12,000 lbs. If you don't believe it's the same trans as in the XJ, look at the part number for a rebuild kit and see what else comes up for the same transmission guts. Excepting the TT Supras, an A340 = an AW4 - and the electronics are simple to harvest from the donor vehicle and wire up.
You don't usually hear about a dead AW4.
The 4L60E, in a Tahoe, had a higher tow rating but still a gross weight hauling around 12,500 - but I've seen them die in bone stuck, unladen trucks too. With frequency.
So, spend a grip of money on adapters or don't. You still need a new transfer case (or adapters which cost more than a decent used transfer case) , shafts, etc
I keep this rig long enough, I'll go AW4 + D300 or Dodge NP20x

If you are going GM trans and durability is even on the radar, go 4L80E

[ZackN920]

You are correct. A 4spd auto is more than just a 4th gear and a lockup converter.

http://www.tciauto.com/tc/gear-ratios/

I disagree, when it comes to what I know. Don't know about the Ford or GM but I know with Chrysler, the A518 Hydraulic 4 speed is a 727 with overdrive tacked on. Exact same gears. Opposite is true comparing a A999 trans to a 42RH. The 999 had higher ratio 1st and 2nd for better acceleration while the later 4 speed that replaced it changed to the same ratio's as the 518.

Don't know about later changes when more electronics got involved.

I am going to go out on a limb here (happy to hear some folks correct/disagree). I think a the value in a 4 speed is more than just the 4th gear. That extra gear means that the engine RPMs don't swing as wildly between gear changes as you drive around and therefor its in its more efficient RPM range more often. With an EFI engine, that all means less injector pulses and more efficiency. That 4 speed is not just our 1-3 with an added gear, its also lower first gear, slightly higher second, same third, then OD.

Don't swing as wildly...HA! I've noticed that a lot of newer vehicles operate the opposite. For example, my 94' burban vs my ex boss's 2002 burban. Didn't take much to put that LS engine at 5K rpm's while accelerating on the highway vs mine that goes to 3500rpms accelerating at around the same rate. And the few 4 banger cars i've been in, same way. Damn tachometer just flies across its whole range, and I'm just driving like I drive my vehicles. Heck, even my 2001 XJ with the 4.0 and AW4, no shiz for me to hit 3500 on average, in town driving. and 4.5K on the highway.
My Dakota, with the craptacular but reliable carb'd 3.9 and the A999 lives in the 2-2500 range during normal driving. The Wagoneer is just a little higher with average in town driving.
Now highway driving, that's different with the older 2. I like to put the pedal on the floor a lot while accelerating