anyone heard of any swaps done using a dana 28 transfer case?
oppinions?

 

Welcome!

Why are you looking at swapping transfer cases?

physically, any year Aero transfer case will swap.

 

doing a little research.. I have access to several of them, and I'm trying to figure something out to do with them.

 

Off hand, I can't really think of anything you could do with them. Sense they are light duty AWD systems, they would not be good for off roading, and due to the lack of RWD cars nowdays, I can't really think of a car that you could transfer it to, to make an AWD car.

We wouldn't mind hearing your ideas and thoughts on possibilities.

 

do you know if they have any gear reduction to them? or are they 1 to 1?
thought about tinkering with one, doing something like an awd buggy or something long those lines...
possibly an all wheel drive golf cart?
lol

 

It is basically an open differential with a power split of 30/70 with an electromagnetic clutch which will kick in and lock the dif for a few seconds for 50/50 split of power. It can not due it for too long, othewise you will burn out the clutch. I would say that it would work for a golf cart, but not too well for a dune buggy. It is designed for on road slick conditions, not 4x4ing.

 

I've been thinking of putting one into a Ranger that's used for rallying. It would be more effective for specifically that sort of use then the manual 2-speed case that's in the truck now. I acknowledge, though, that my usage is far from typical.

I would think it would be worthwhile in a V6 Explorer too, assuming the driver doesn't go offroading. It would be an AWD system that is very comparible to the V8 case in terms of on-road function.

Regarding the clutch engagement duration, the word I have from the Aerostar's former AWD system engineer is that engaging it manually with a switch would actually be a little easier on the clutch, since it had a fair amount of torque capacity and that leaving it engaged (in foul conditions and such) would potentially extend the life of the clutch because it would eliminate the continuous slippage from repeated engaging/disengaging that you might encounter on a bad road...

 

I thought that the transfer cases in Aerostars were all Dana 28's. I am intrigued by the idea of an over-ride switch to force the 50/50 split. I have used the full AWD capabilities 3 times this week. (12" of snow on the ground) I broke trail with no problems other than seeing the trail of my shock arms next to the tires tracks. Anyone have a general rule for clearance before high centering? Why is the Dana 28 weak. Electro-magnetic clutching should/could be ok. Are the clutch packs insufficient? Are the plates bad? I would not mind having a spare transfer case myself. I am considering going to look for the 4:10 ratio axles with the positrack diffs. The axle number exists. The idea would be to lower the stress on the drive systems and increase low speed power. Anyway, what transfer case is in the Aerostar? Thanks chad

 

All AWD Aerostars have the Dana 28 t-case. I don't think it is particularly weak, at least not internally. There were some issues with the cast housing, IIRC, though. There was a 100% recall for them - the magnesium casing tended to stress crack with the vibration generated by powertrain bending. IIRC, the "fix" was a tubular brace that links the t-case right to the back of the engine block... But I don't think the center diff or the clutch is really weak, at least not relative to the load the van normally puts on it.

 

This may be something better handled with the PM environment, but, here goes anyway. The idea of a switch by passing/overriding the computer input and giving me control to go to 50/50 before I slip is of use to me. I backed up over a curb onto my "lawn" to place my tail gate close to my "load". The rear wheels climbed the curb well with the 30% push from the front. When I eased the front wheels to the same curb, I had to "spin" the rear wheels first before I got the 50/50 allowing the front wheels to climb the same curb. If I had had an over-ride available, I would not have had to "force the spin". Aside from gas milage, what is the problem with running 50/50 on demand. Could the computer be tricked into complacency (not damaged)? It seems that it would be relatively simple to imput the correct amperage to activate the servo (or whatever switching mechanism is used to activate the electromagnetic clutch). What would be the down side of this. thanks chad

 

I don't think the gas mileage would be affected, you wouldn't use it driving down the road normally. Even if you did, I'm not sure it would make a significant difference there. Anyway, I can't think of a downside - again, assuming you only used it were appropriate. Like I said, the Ford engineer who worked on this system suggested this to me, with the idea it might be an improvement.

IIRC, the activation of the clutch is done a switched ground, by the control module. I was picturing a 3-position switch (like the rotary 4WD switch in an Explorer or Ranger). One position would be Auto - in that position, the ground wire from the t-case is route to the control module like normal. Beyond that, there's a Lock and an Open setting. In Lock mode, the switch routes the ground to a local ground, thereby locking the clutch. And in open mode, it doesn't hook to anything, preventing it from closing the clutch.

There really is no good reason to wire it for an "Open" mode that can't lock. I was thinking of it 1) because I could, 2) the 3-position 4WD switch has a 3rd position to use, and maybe C) being open allows for handbrake turns on snow - in automode, it'll lock the clutch, which tries to stop the front wheels too. That make's the van simply plow off the road rather then swap ends. That is, of course, not recommended driving technique for a van of any sort, so that justification for an Open mode is not to be taken seriously...

 

The downside is when you forget to turn off the switch and drive with the clutch fully engaged. It'll probably overheat your clutch coil and, if you are driving on asphalt, it'll most likely damage your drivetrain due to mismatches in tire diameters between front and rear. If you must do it, I'd recommend a push-button momentary switch, but then it'll be hard to drive with one hand while the other hand is on the switch

 

You know, It might be interesting to just throw an LED or low voltage Bulb into that circuit. The light would need to be wired to go on when you are in 50/50 and off when you are in the 70/30 normal distribution. It would show you when and if your clutches were active. (a first step in setting up the inline "switch") I am Really considering doing this. Copper, you are right, forgetting to "unlock" could/would be a bad thing. I used to have a CJ with front and rear dif "lockers" for emergency dig outs. This was in addition to the 4 wheel drive. Talk about a problem if you don't unlock. A turn on dry pavement with the front differential locked was definitely a way to destroy the front differential axles etc. I don't think the AS with this modification would be as bad as that. Torsen Rick, could you help me ID which wire etc. I will check my Chilton (I still can't get past the d*mned Bit torrent thing). Once I ID what I believe is the correct circuit, I would like to "post" my wire before I cut it. At a minimum I will wire in the new "Indicator light". (just a control freak thing). thanks to all. chad

 

That was why I said that there was no downside - if used when appropriate.

But anyway, about the wiring - I posted just last week (I think) a link to a site that had the wiring diagram and explaination of the system. That thread is here. You can see that there are two wires going into the transfer case solenoid (which actuates the clutch). One is powered with the ignition, the other is the ground, routed back to the control module, where it appears to be switched internally. You'd just have to make an inline switch that routes that wire to a second ground.

 

I found Torsen Ricks link. After looking and reading, I posted a couple of more questions under an AWD thread that belongs to Torsen Rick. I read the responses to my questions under AWD about heat build up in the electromagnetic side of the clutching lockup. I now know that the 4WD light that I see on startup is supposed to go on when the clutch is engaging. (I have to go slip the rears to see if the light really works and, yes, I have gotten into a refrigerator to see if the light really went out when the door closed. ) I will do some more Dana 28 research and post my final plan. If nothing else, this will educate me in the ways of the Aerostar AWD system and provide some amusement for the group. thanks chad