95-96 4auto to 4hi conversion???

[mikefox]

Here are the pic locations I scanned from my Helms manual I mentioned in my previous post:

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Once you read my previous comments in Ray's posting you can see that this might be harder then we expect. If anyone has any ideas as to what to try next I am open for suggestions.

[Edited by mikefox on 10-27-2000 at 09:59 PM]

 

[NoBoundaries]

Have you looked at the 98+ Ranger T-cases? They have 2wd, 4wd High, and 4wd Low, maybe the Ranger case is some variation of the 95-96 Explorer T-case. Maybe a compare and contrast of the 2 systems might help you better in finding an answer.

 

[mikefox]

More findings...

I am puting up these pics and showing my idea for how a 3-way switch might be able to be installed to give you 4HI when your selector is in 4auto:

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Sorry for the crude drawing, but I hope you get the idea I had. Once I actually try this I will let everyone know if it works or not. Did not work.
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Part '40' is the magnetic clutch coil that seems to be what engages the front driveline in 4auto mode as best as I can tell. That is what my drawing is trying to show as giving it a 12V source to engage it in the 4auto mode when you want.
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[Edited by mikefox on 12-21-2000 at 01:43 AM]

 

[Maxxim_Hacks]

Re: More findings...

So did it work because if it didn't i'm doin' the dirty-harry and try to bolt on a ranger t-case. I have a buddy who has a '99 ranger that got shmucked by a semi...I can literally lift the box off the frame rails with one hand. The rails are about 14"-15" apart from each other. But sorry to go off on a tangent. Hope it worked for you so I can give it a try!

 

[mikefox]

Sorry I haven't updated this lately. I haven't had a chance to got out and test this yet. I really don't know if it is going to work or not. I did wire it all up just haven't tested. I promise, when I do, I will update you all. If you are able to get the transfer case from your friend for next to nothing (depending on how good a friend he really is, of course) that might be a better way of going. Just a thought.

 

[mikefox]

update...

I have done a little testing this last week. We had a little bit of snow one day and then if froze that night. I tested
with the auto and then with my idea. In auto, on ice, I could accelerate with very little slippage, which is what it should do and I do like that on the street from a stop. I then tried my idea and it felt like all four wheels were spinning like any other 4 hi system would. I probably needed someone outside to see for sure or me outside and somebody inside doing the driving. I am sorry I can't provide any better test result as of this time. Someday I hope I can get out and really test it.

Also, I have changed the wiring schematic above to show exactly what I did.

 

[Tom Wilk]

Mike, nice work! I have a later model and have the opposite problem; no 2wd. I will have to get a wiring diagram/pinout for the system used on 99's (maybe I'll break down and buy the Helm's book). I suspect it is similar, but not exactly the same. BTW, I like that "Other wires going to other things" nomenclature.

One question: Do you have some type of disconnect in the front axle or are the wheels always engaged to the differential up there? My Chilton's shows a vacuum disconnector up front, but I have none. Maybe that only existed on models with selectable 2wd.

 

[mikefox]

Tom, thanks. Yes, the 95-96 models have a vacuum disconnect for the front axle on the pass. side. It works like this: when in 2wd the vacuum is applied to one side of the diaphragm and then in 4wd vacuum is applied to the other side of it and moves the acctuator over to engage the front axles.

In 97 they did away with it as well as the 2wd/4auto/4low and gave you the 4auto/4hi/4low. I have heard that the T/C are the same for either years 95 and up. The main difference being the vacuum disconnect and probably the programming of the GEM. I have scanned the pics of the disconnect and put them somewhere. I will have to find them and post them if you want to see them. Any more questions just ask.
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As far as my nomenclature goes, it was the best thing to come up with since I wasn't doing anything with those wires in the first place. They are shown in the diagram under the T/C parts breakdown.

[Edited by mikefox on 12-21-2000 at 10:07 AM]

 

[NoBoundaries]

I am very impressed with all the work you have done Mike. I just have one quick question. Do you know what would be involved in putting a 97+ t-case on a 95-96?

 

[Jim F]

Vacuum disconnect

I wonder why Ford did away with the vacuum disconnect. My 98 doen't have one either. It could have been a weak link in the IFS system, don't know. I do understand that my 98 is supposed to go into 2WD once it reaches 35MPH. Maybe this was their fix, eliminate driver input and make it a traction control system to 2WD transfer automatically. Hey there's that word "auto".

Mike, I was impressed by the jpg files, but the recent photo's on photopoint don't print out clear and am unable to save them as jps's. When I saved the jpg images, I was able to print out readable pictures through a graphic program. Oh by the way, great last name.

 

[mikefox]

NoBoundaries, I believe the T/C are the same for 95-96 and 97 and newer. Somebody has posted that before here somewhere. The only difference in the systems from 95 and 97 is the front axle vacuum disconnect and probably the programming in the GEM. But I am not 100% sure if that is true, I am only going on someones post that I saw.

Jim, 95-96 also has the feature that when you hit 35 you lose the 4auto and goes into 2wd. Just the switch doesn't move. The GEM controls all that with inputs from the speed sensors in the T/C. These also help with the 4auto function. I will put up better pics then the photopoint ones in just a short time. i don't know why the photopoint ones look so crapy. I scanned them on the same scanner and everything.

As far as my last name goes, what can I say. When you got it you got it.

 

[Maxxim_Hacks]

Hey Mike, one thing that i am having the darnest time figuring out is the implication of two on/off/on toggles instead of using one and connecting the clutch coil assembly to the center terminal and the 12VDC to one outside terminal and the brown wire, I do believe it was numbericaly assigned (779) but i could be wrong to the other side. But then I thought to myself, maybe Mike is using lighted toggles, and that would explain why one side has nothing connected to it. But after thinking about the logic used in wiring a lighted toggle, it became evident that the first toggle, used to engage the 4auto function, could not be lighted consistently because of the varying amounts of current flow through the circuit.

Now if you have any idea about what I just said, let me know if I am the only one who is thinking about this topic a little to indepth.

Oh, and by the way, ALL the t-cases for the rangers, explorers and the escapes are the same with the exception of the front housing. In the 95-96 explorers, it is a one piece housing and on the 97-up explorers and rangers it is two.

And on a little side-note... Putting a '99 ranger t-case will NOT solve all your problems. My GEM got ****** up and had to be reprogrammed and I am now right where I started at. Oh and by the way, does anyone want a '99 ranger t-case w/ 11k miles!!! Dirt Cheap!!!

 

[mikefox]

Maxxim_Hacks, my original idea was to use a single 3-way switch. But I could not find one that I wanted to use. So I decided to go with the 2 seperate lighted switches. I don't have them wired to light up, though. So yes, a single 3-way switch would work just fine if you could find the one you want to use. The biggest thing is to make sure the 2 brown wires from the relays are together. And the wires going to the T/C, brown, come together after the switches (does that make sense). If not I don't think it would work. And make sure the connectors used allow you to put it all back the way it was if needed. Example: I used females on the relay wires and males on the wires going to the T/C clutch.

Did you mess up your GEM by installing the 99 T/C? If so, that is a good thing to know. It would probably happen with a 97 as well.

 

[Maxxim_Hacks]

Yes Mike, as a matter of fact, I did bomb my GEM when I dropped in the '99 ranger t-case. Another thing I forgot to mention is that the t-case out of a ranger has a different clutch/band system in it. On the 95-96 explorers, it uses varying amounts of juice to control traction percentages. You can see exacttly how much power is being transfered to the front end with a multimeter. At about 6VDC, the clutch dissengages to the point of transfering roughly 14-18% to the front tires, at 8VDC, it sends about 23-27% up front and at 10VDC, it sends about 32-36% to the front and anything above 11VDC sends about 41-45% to the front tires. On the 97-up explorers the voltage points are about the same but the percentages are a little different. On the 98-up rangers, the GEM sends a steady 12VDC and the transfer is about 50/50 between the front and back. I do think one could make it work by pulling the GEM out of a ranger but then what else would one screw up in the process.

By the way, I'm selling the ranger t-case $1,000,000 or best offer!!!

 

[mikefox]

Maxxim, where did you get the figures for the % with voltage readings? That is something I have never seen before. Pretting interesting.

Well if applying 12V to the T/C clutch works for the Ranger do you think my idea has any validity as to whether it will work or not? I think if we were to change the GEMs then we would lose some functions for sure. Like PW, PD, Alarms, etc. Just my thought on that.

 

[NoBoundaries]

This is alll way too complex!!! It sounds as even if you could get it accomplished, how reliable will your Explorer's 4wd system be when you are done? Would just putting a manual t-case on work? I am now considering doing this because it appears to be the only reliable option. Are the manual t-cases on the Bronco II, Rangers, and Explorers any good?

 

[NoBoundaries]

It also appears that if I use a manual t-case, that I would also need a front axle from a 1998+ Explorer because of the vacuum disconnect in the 95-96 front axles. Is this a correct assumption?

 

[Maxxim_Hacks]

Mike, I talked to one of the prototyping-engineers for the E-II project (supposedly Ford thought it would be cool to continue the Explorer's name badge with it's 4 door SUV replacement, the Escape) and he explained to me the varying voltages and such. He said my best bet was to scrap the idea while I was still ahead because after altering everything that was necessary, I would be farther behind than just dropping in a manual t-case from a '90-'94 explorer. He said just make sure that if you go this route, when you do manually engage the 4wd, to turn dash selector to 4x4auto and when not in 4wd put it back in 2wd. I see where he is coming from because after modifying everything I still am left with a weak link in the drivetrain. he told me to look in the boneyards for one off of an explorer or a navajo. As for the front disconect, if mike is right, you sould be able to wire it to a toggle and then have the added benifits of 2lo, like pulling that cigar-boat out of the landing! Right... If I had a cigar-boat, I'd have an expedition that was lifted so high I'd need a 20" drop bumper just so i was legal!!!

 

[mikefox]

Well, I might have to start looking into a manual T/C as well and see what cost is involved.

You having giving some needed information that I probably couldn't have gotten on my own. I really appreciate all of this info. I am sure others will like to see it as well.

 

[NoBoundaries]

Thanks to Maaxim, Mike, and Tom for all the help and info. I think you can find a manual t-case for pretty cheap in a yard. I was about ready to go and get a new front axle, but if just putting it 4wd Auto will do the trick, then that makes my life easier! Thanks guys!