Convert a 2WD Aerostar to AWD???
 

Is it possible to convert a 1993 2WD Aerostar EB with a A4LD to a AWD drivetrain? Has anyone done it, and how much work is it?

I am a Subaru veteran (this is my first time posting), and the mod capeabilities of soobs is endless - older 2wd car to AWD is not hard at all on those cars - in fact it is a relatively easy bolt-in change.

Traction on snow (or anything else) in a stock 2WD Aerostar leaves MUCH to be desired (especially when compared to a vintage soob). How good is the AWD drivetrain overall? Is it as reliable and rugged as the 2WD? Gas mileage difference between 2wd and AWD? Handeling? Maitnence? Are there different versions of the AWD? If so what are they like? I have a 1993 FSM for the drivetrain, but I don't know how similar other model years are.

AWD Aerostars are not common around here, but my chassis/body is rust-free, and all I guess would really need is a donor car of sorts.

Thanks :D

You would need the Transfer case, drive shafts, front dif, front suspension, CVs, Hubs, Module under drivers seat, possibly wire harnes, PCM (maybe), plus some other stuff that I can't think of right now. If you have done swaps on Soobs, then this would not be too tuff for you, but for the average joe, I would recomend just buying an AWD, it would be cheaper in the long run.

yeah, and be sure to post how it turs out, sounds like a fun job.

It may or may not be cheaper - my engine has less than 50k on it.
I guess my main concern is the performance difference between 2WD and 4WD - everyone seems to like the 4WD handling and stability.
I was thinking about just dropping the whole front crossmember out of both cars, and switching them that way. I know it is very doable in soobs (if desired - though the engine is so easy to get out it is pointless). I think it is also possible to drop it on an Aerostar. The wiring is limited to a single control module with two rev sensors (one in each diff), a inhibitor for when the brakes are enguaged and when out of gear, and the locking mechanism control itself. The AWD unit will function fine without the control unit - it is just to help you when you are REALLY sliding.

I am not quite sure what you mean by "Performance Difference?"

If you are looking for straight line acceleration, keep it RWD and add a locker in the back. You will loose less HP/TQ in the driveline and performance parts for the Ranger/Explorer do transfer over.

If you mean extreme driving conditions (snow/ice/rain/mud), yes AWD is better, and better yet if it has a rear LS Diff. If you have access to all the parts, then go for the transplant.

BTW you did not mention what size engine was in your EB 50k mi engine was a 3.0 or 4.0? If it is a 3.0 I am not sure if it will be torque'y enough for AWD.

It's a 4.0L engine.

I have little interest in improving acceleration - it's a van - if it's got a lot of torque, (which it does) I am happy.

I leave 0-60's for sports cars.

However, I am VERY interested in improving traction, as it is pretty poor in most any inclimate weather - forget snow, even with added weight in the back end - it still fishtails out of control.

My Soob is 20 years old, and my personal car, the Aerostar is the family go-everywhere van, so it needs to be able to go everywhere.

It will probably be a while before I can get around to doing the change (like summer), but I am certainly thinking about it. I have the EVTM manual for my van, and I found the PCM's are identical 4WD/2WD - the 4WD A4LD is beefier, but other than that, it is a very similar unit to the 2WD. I also have the powertrain manual for it, so I can rebuilt the tranny/transfer case if necessary.

I will see how much the parts actually cost before I decide to do the conversion. I hope to find a parts van that has been rear - ended or something like that.

What is your axle code (on inside drivers door?)

Yes they are identical in that they are EEC-IV's, but the programing might be different.

hhhmmm.... I have never heard of a difference in parts in the A4LD RWD vs AWD. What are the differences in the two? :-huh

I would just transfer the front crossmember/Dana 28 IFS axle from the AWD version. I would chuck the transfer case and use a Ranger/BII transfer case. I would use the manual shift version as it should have plenty of room between the seats to put in the shifter. Even if you had the 3.0, it still would have enough oomph to move it as they used it in 4WD Rangers. You would need a 4WD A4LD as it would have the longer mainshaft in it. You would also need the extension housing between trans and tc. It would be musch better than the computer controlled garbage and much cheaper too. I wanted to do it on my 93 with a 3.0 but I sold it.

The back end of the transmission is different (for mating with the transfer case). The oil pan and oil filter are also larger (I checked in the 1993 powertrain manual) - I suppose that the AWD one has much more oppertunity to overheat, so the larger pan is to prevent that. Beefier, but not much.

The main reason I am interested in the AWD unit and not the manual shift is because I want the traction controls to be there without driver involvement, though I will hook up a dummy switch to engage the transfer case lock manually. I have the factory wiring diagram for it, and it looks easy - I recently converted my soob to fuel injection - wiring in the AWD computer will be 1000 times easier. Besides all the computer does is lock the transfer case when it detects slippage - planitary gears handle normal operation.

I think the actual transfer case out of an Aerostar would be cheaper because it is out of an Aerostar, but I may be wrong.

I think a lot of junkyards just see the transfer case as a transfer case and attach a price to it regardless of what it was removed from.

BTW - if you do rebuild it, I was told by the engineer that headed up the AWD system in these vans (we do a lot of work with him on current programs) that these cases are highly susceptible to overheating if they are even slightly overfilled. Along the same lines, he also told me that oil tended to foam in a freshly rebuilt and resealed case (leading to oil being vented out) because it reacted with the sealant, so an anti-foaming agent was required with the first fill...

Aerocolorado, are you reading this? Isn't this what happened when you rebuilt your T/C?

Sounds awfully familiar, initial leakage out the top vent. I just assumed I had overfilled the case but foaming could well explain that as well. My trusty Ford workshop manual didn't mention anything about this - guess that's why all the later TSB's. Thanks for the headsup copper_. (Still scratching my head as to why a slight overfill would lead to overheating)

He explained it to me, but I'll be damned if I can recall. Additional friction from pushing the t-case chain through a higher volume of oil rather then air comes to mind, but I'll have to check when I see him next. I do recall that he said it was very sensitive to fill level though, and that temps climbed rapidly when it was overfilled...

thanks for the heads up - that's the kind of info I need

I am a little surprised at Ford spacing RTV for the transfer case sealing compound - I would expect something a little more rugged - in my experience RTV is forgiving overall, but not good under pressure or heat - I generally use Permatex High-Temp Copper sealant b/c it is related to good ol' RTV, but more rugged.

Silicone sealant is common on Ford axles, t-cases, and transaxles. Or at least with the ones I've worked with. I don't know how much that really saves them over the cost of actual gaskets, at least for things like axle covers. I also don't know what varient of it they use in production, but we've often used the common red medium to higher-temp Permatex that you can buy at Advance Autoparts...