A4LD variant questions. | Ford Explorer Forums - Serious Explorations

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A4LD variant questions.


New Member
April 6, 2006
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City, State
Brampton, Ont
Year, Model & Trim Level
89 Mustang

I have 2 A4LD related questions:

Is there as physical difference between a valve body for a 2/3 N/A vs. Turbo?

The vacuum modulator - what is the difference between the turbo one and the n/a one?

I ask here, after reading the wicked rebuild write up done by Glacier991, it seemed like the most common sense place to ask a a4ld related question.

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I'm not sure I know what you mean a "2/3 N/A"... as for the modulator I am unaware of any differences. There COULD be some differences in Valve Body components, I doubt much if any though, but I cannot authoritatively answer that question, I'm sorry.

I am guessing you mean the 2.3 Liter normally aspirated engine verses the 2.3 Liter turbo engine? I cannot help with the answer, but I thought that might help Glacier. :)

Welcome to this forum! I was also wondering what the difference is between the regular modulator, and the turbo version. I think it is just calibrated differently, but they do cost a lot more than the regular one. On another website, I saw that they are a different size. Check this link for some more information: http://www.explorerforum.com/forums/showthread.php?t=156302

Here is the information that is on Aceomatic's website:

Description Illust. Qty. Year Part# Reference
Single Dia - 1.330" 2701 1 1985-94 2272701
Single Dia - With Adjustment Wheel 2701 1 1985-94 2272703
Single Dia - ( Turbo ) Green Body ( 1.320" ) 2701 1 1985-UP94 2372705
Modulator Pin Gauge & Pin Stock 1 ALL 2262710

Yes I did the turbo swap. I run a t-5 currently. I bought a complete 87 turbo coupe with the 2.3L turbo lima block. It came with a good T-5 and a 8.8 3.55 trac-lock. The original drivetrain had only 125,000 kms (about 60,000 miles) on it (2.3 normally aspirated, a4ld) The original a4ld worked perfectly, and was run with a oil cooler. Why I am asking this question is that I got a good set of OEM forged pistons for the 2.3 n/a block and was considering doing a low psi (8-9lbs) turbo. I already have a LB3 ecu, but I know some guys who have swapped the turbo motor and ecu into their cars with their a4ld's and had 3-4 lock up issues.

After reading Glaciers post on the rebuild, he had a graphic which showed how many check balls were used in each transmission relative to the engine it was mated to in the trans valve body.

That's why I am wondering if the a4ld which was originally bolted to the normaly aspirated motor, can be used successfully, if I was to leave out the extra check balls - as to be identical in set up to the turbo motor - and - install the turbo vacuum modulator?

In the long run, I have access to a '92 explorer (good body, blown motor and iffy trans) which I could convert to 2wd and install the turbo motor and trans. 160-175 hp and 26-28 mpg with 3.73 rear would be nice. Plus my wife could drive it...

I happen to have the output shaft and tailpiece housing for the 2WD conversion if you are interested. As to the rest I declare ignorance.

I would hazard to guess that shipping those two items would be cost prohibitive out to me. I have an abundance of wrecking yards within 1.5 hrs driving distance which happen to have quite a few explorers and rangers. Funny thing is, many are missing the trans....

I don't think a wrecking yard would tear apart a good transmission for you just to get the output shaft, and extension housing. As for the VB check balls, I wouldn't make any changes to the original pattern if the VB came that way. I don't know if the flow pattern of a VB that originally came with a turbo motor setup would be different for a VB that is connected to a different motor. You could experiment by rearranging the check balls, and see if there is any noticeable difference. I'm very curious to find out if the pattern would improve, or impede the shift performance. If it doesn't work properly, you could always put back the original check ball configuration.

In the long run, I have access to a '92 explorer (good body, blown motor and iffy trans) which I could convert to 2wd and install the turbo motor and trans. 160-175 hp and 26-28 mpg with 3.73 rear would be nice. Plus my wife could drive it...

With the added weight of the truck, it won't get 26-28 MPG. Also since it's a 4 cylinder, it will have to work a lot harder to move the truck, so in the long run, your gas milage will probably be even worse than the 4 Liter.

Well thanks for the responses. Regarding the valve body check balls, Ill refer to this:


As you can see there is a difference in the way the set up is. I did get the chance to head up to a wrecker, and they had a TC a4ld. The valve body was identical - that's a good thing.

91 and up were the models that could be used with LB3 & 8UA ecus for proper computer controlled lock up..

As to the weight issue, I have at my disposal a 1990 bronco II and a first gen 2 door explorer. I'm leaning towards the bronco as it is lighter (at 3200 lbs) and shares a lot with the ranger (engine mounts, transmission crossmembers, et al). Dropping in the 2.3 would be fairly straightforward, plus running a conservative 10 psi of boost, I would be pushing 160 hp - 210 ft/lb torque. Much better than 140hp/170ft lbs off the 2.9. Pushing the boost up to 15 psi would give me 200.

That chart also refers to an illustration. Could you post that too? Is it possible to blow up the size of that first chart? It is a little hard for me to read what it says. I could make out a few things, but not everything.

The extension housing would be a piece of cake to harvest off a donor. The output shaft would not be as it is the very last thing to come out of a completely disassembled tranny.

Yep the o/p shaft would be a hard for wrecker to pull, but dead a4ld cores from rangers and explorers are cheap and plentiful where I am.

I also found out that you can take a valve body from a TC and use it on an earlier a4ld to get the computer controlled lock up if so desired.

I was reading my ATSG manual and in it states that late 88 to 90 also use dual solenoid set up, but on the a4ld I pulled out of my '89 stang it's only one. Go figure.....

Brooklynbay, I took the graphic from Glacier991's incredible write up, Part III if I'm not to be mistaken. Dunno why it shrank down like that?