How to: Manual Control for '95 -'96 Vacuum Disconnect Front Axles

[BAYDOG]

JDraper...awsome write up!! If I may clarify for those who don't understand the front axel set up , and have never had their axels out..... On the front passenger side of the axel, there is a box of sorts. There, the passenger side axel out to the cv joint, is a two peice shaft. Now with the the switch in the cab in 2x4 mode, the shafts in the box are not connected, and thus , the passenger side wheel is never connected to the differencial, it spins at what ever speed it needs, never affecting the gears inside the pig. When you engage 4x4 auto or 4x4 low, there is a collar on a shift fork, that slides over, and connects the drive shaft coming out of the differncial, to the drive shaft going to the passenger side wheel, locking them together. So what this mod does, is ...... When you switch the selector in the cab to 4 wheel auto, and use his switch to unlock position, it will send power to the front end , and only to the driverside wheel, because the shift fork on the passenger side never locks the two drive shafts together, thus 3 wheel drive. Or if you select 4 wheel auto, and lock on on his switch, it acts just like it came from the factory, allowing the shift fork to be moved over , and locking both drive shafts as one.

 

[95exploderboy]

Is anyone aware of weather this will work in my situation. I have swaped to the BW 13-54 manual TC in my 95 Sport. Can i use this mod and to lock the front axel? or does this just switch the passenger side? Am i to assume that when i shift into 4wheel with the lever, you are saying that the drivers side will spin, when there is power applied to the front driveshaft, or is there more to the system than the driveshaft getting power. Is there something else that has to be engaged for me to have power going to the front, after i shift into 4wd. I did the swap because my old TC was bad, and figured i would sort out the rest of the details later. Its gettin close to winter and I'd like to get this working. I'd appreciate hearing from anyone with ideas or input.

Thanks

Jake

 

[JDraper]

This mod only disconnects the right front wheel.

From what you are saying, you no longer use the switch on the dash since your xfer case is manual?? If that's the case, you don't currently have 4wd. You need to do this mod so you really have 4wd. The stock switch on the dash controls the axle disconnect. If you leave it in 2wd, your right front wheel will always be disconnected from the drivetrain, and since the stock front is an open diff, you will have no power applied to the ground up front. You can either do this mod, or replace your passenger's side axle shaft with one from a 97-2001 explorer.

 

[95exploderboy]

what about my left fron wheel is that getting any power, if the diff decides to send power that way? i'm asking if the vac. disconnect on the axel is the only other thing in the 4wd system that would stop my front from working as long as i have power to the front driveshaft. i know you guys are saying about it disconnecting the right side, but why is the right side so important, isn't this what controls weather the whole axel gets power, and its only the diff which decides which wheel it goes to because its a open diff?

 

[blue_97_v8]

so this will make "4x4 auto" in to true 4x4?? my son's 96 has this stupid auto 4x4 and it sound's really bad when it slip's

 

[JDraper]

95exploderboy, an open differential sends power to the side with the least resistance, so the left front wheel will never see any significant power as long as the right front wheel is disconnected. Try locking the truck in 4lo, and raise the left front wheel off the ground. You will be able to spin the left front wheel by hand. Without that locking collar engaging the right front wheel, you will not have 4wd with an open front diff. Even with it engaging, it's not true 4wd because the open diff will only power one wheel at a time. To get true 4WD you need to lock the differentials.


blue_97_V8, this does not create a true 4x4 because the xfer case is not affected. The xfer case in the newer model trucks has a clutch inside it that engages and disengages when the truck senses wheel slip. When you put the truck in 4 Auto, the front axle locking collar is engaged, it's the xfer case that is causing the thump you feel. There should be a way to override it by figuring out what signal the xfer case wants to see for the clutch to be engaged. Baydog and I have discussed this in PM's, but since I no longer have the '96 in my possesion (gave it back to the owner), I can't hunt down the solution. I would think you could look at the xfer case control wire (brown wire under the driver's seat. See http://www.explorerforum.com/forums/showthread.php?s=&threadid=41956. It's long, and the good stuff doesn't start until about page 3 when the correct way to do the mod is discovered.) with an oscilloscope to see what signal causes the xfer case to be engaged, and then artifically insert that signal into the wire.

 

[blue_97_v8]

ok im pretty confused but what i have gathered is to put a switch in that i can switch power to the brown wire but not 12 volt's cause that's to much?

sorry im just confused..

 

[JDraper]

Originally posted by blue_97_v8
ok im pretty confused but what i have gathered is to put a switch in that i can switch power to the brown wire but not 12 volt's cause that's to much?

sorry im just confused..

You are correct on your statement about the brown wire. You can put a switch in it to cut power to the xfer case, which gives you 2WD. However, you cannot just apply 12V to the same wire to get 4WD because it takes a frequency modulated signal, not just a 12V signal.

 

[blue_97_v8]

hmm i think i will just end up putting a transfercase from a ranger/explorer sport(01-up) or sport trac in so it will have true 4x4

 

[Premier]

This mod only disconnects the right front wheel.

From what you are saying, you no longer use the switch on the dash since your xfer case is manual?? If that's the case, you don't currently have 4wd. You need to do this mod so you really have 4wd. The stock switch on the dash controls the axle disconnect. If you leave it in 2wd, your right front wheel will always be disconnected from the drivetrain, and since the stock front is an open diff, you will have no power applied to the ground up front. You can either do this mod, or replace your passenger's side axle shaft with one from a 97-2001 explorer.

Just wanted to bump. I will be doing this soon. I have now installed a bw 1354m, and in 4wd(I have a no-slip in front) my right front tire will not spin. This is going to sound repetative, but doing this will alow me to engage in true 4x4 yes?

Let me also add, that when I do flip the switch on the dash to 4auto or 4lo, it does nothing. Is this because there is no feedback from the electric t-case? Thanks

 

[JDraper]

Premier, the answer to both your questions is yes

 

[Premier]

Thanks Draper, your the man!

 

[Premier]

Hooked it up(finally) and it works! Thanks again.

 

[AspenX]

This is what they call the brown wire mod, right?

 

[JDraper]

Nope, this is different. The '95 & '96 Explorers have a vacuum disconnect on the front axle that lets you put a lunchbox locker inthe front and operate it like an air locker. It disconnects the right front wheel from the drivetrain.

 

[Bronco638]

The 'brown wire mod' is for (somewhat) controlling the transfer case.

 

[FoxFan]

o.k. hold on, my Ltd. only has 2WD,4WD AUTO,4WD LO.

if i want 4WD HI instead of 4WD AUTO i just have to do this mod?

what @ low range, i don't lose it do i?

 

[FoxFan]

ttt

 

[JDraper]

This mod does not give you 4WD hi. It allows you to effectively have a 2WD low. It does not cause the loss of low range. As said above, all it does is allow you to uncouple the right front wheel from the drivetrain at will. This allows those who wish to run a front locker to use a Powertrax or other auto locker turn the truck without binding up the drivetrain.

To accomplish a true 4WD High you will have to figure out how to send the proper signal to the xfer case to lock up the clutches. There has been a lot of talk about that here, but I don't know if anyone has sucessfully done it yet.

Read this whole thread carefully and your questions are all answered. blue_97_V8 asked the exact same questions.....

 

[Premier]

Ok, I finally got around to installing my switch into the dash(was hanging down near my feet). Since I have a manual t-case, I put it in the switch location. Only thing now, is my 4wd lights blink?

Oh, and its already labeled