Buddy of mine has a F*&d and he is getting a kit so when he engages 4x4 low, the front end will not engage. This got me to thinking, can we do something similar? I know our drivelines are different than F&%d's but do you think this is possible?

For those wondering, "Why would you want to do this?" Some folks engage 4 low when backing heavy trailers up inclines etc. Just thought this might reduce some wear and tear.

I can put my 85 Ford in 4 low and leave the front hubs unlocked so that I can manuever ever so slowly when needed. The truck is a stick so it helped a lot to be able to crawl the truck sometimes when manuevering.

DEWFPO

It would be easy to install a switch to disable the front axle disconnect so that it does not lock in the front when you shift to 4WD.

If you have manual 4wd you can pull the fuse or better yet find the wire and splice in a switch, that will keep the front axle from engaging.
Not sure how you would do it if you have push-button 4wd:confused:

SOMEONE FIND ME THAT WIRE!!!! I WANT IT!!!!!!!!!!!:eek: :eek: :eek:

I guess I am missing something here.
Why would you need to be in 4 low and only at the rears?
If you are needing to be in 4 low than you are wanting to have the traction and the torque to be able to move. By putting the load to only your rear tires then, especially on a pickup, you loose a lot of traction ability.
But than again I only use it snow.

it's also nice to just be able to back up real slow with a trailer say into a tight spot or something. This would be extremely handy for those of us with the ZF so as not to ride the clutch as much!!

You would have to get creative to do it. The front axle actuator has a control circuit and a signal circuit from the tccm. The tccm requests the actuator to lock and the actuator sends a signal back when locked. If this doesn't happen the transfer case won't shift.

Does this hold true for the manual shift transfer case as well?

It's basically the same for the manual shift except the transfer case will be in 4wd even if the axle doesn't engage. When the axle engages is also sends a signal to the pcm and tccm. The pcm changes the shift and abs strategies for 4wd. In 4lo the trans probably won't upshift if the signal is not sent.

OK, this still doesn't sound like such a bad thing, because I've got the ZF-6, together with the manual transfer case. All I want is for the front wheels NOT to grab when I'm in low range. So long as the rear wheels go to low range and the front is still free wheeling, I'm ok with that. Of course all this so long as this doesn't damage the truck or set codes.

Probably the safest way to disengage the front would be manual hubs if they make them for our application.

I'm just looking for another cheap but awesome mod like the headlight mod was. Great convenience without the $$$$.

Remember that shifting the xfer case from Hi to Low range changes the output torque (2X). Without the front drive components sharing this increased torque, the rear drive components must be able use this torque without being damaged.

My .02.

Idahofox

that is not a concern i don't think. the drive train is the last thing i would worry about after watching the truck pulls. they already have over a 1000 lb ft of torque at the rear wheels anyway.

It's basically the same for the manual shift except the transfer case will be in 4wd even if the axle doesn't engage. When the axle engages is also sends a signal to the pcm and tccm. The pcm changes the shift and abs strategies for 4wd. In 4lo the trans probably won't upshift if the signal is not sent.
Are you sure I don't remember seeing any electic crap be between 4 WD shifter and tranfer case just linkage.

Probably the safest way to disengage the front would be manual hubs if they make them for our application.
A company makes it for 88-99. It was in the jegs catalog

Are you sure I don't remember seeing any electic crap be between 4 WD shifter and tranfer case just linkage.That's why it will shift into 4wd on a manual case. The electrical crap is on the front axle.

Here the manual front axle engagement but it only for 88-98
http://www.4x4posi-lok.com/app_chevy-k.html

So if I'm understanding this all correctly, with the fuse out, or a switch spliced in, the manual transfer-case will shift to 4lo, the rear AND front DRIVESHAFTS will turn, but the front axle won't engage correct? Messed up shift points is a non issue with the ZF-6, and besides I'll only be using this in reverse anyway to back up trailers and such. If there is any adverse effects like the computer setting codes and such, then I want to stay away from it. But if not, then I'd really like to set this up.

So if I'm understanding this all correctly, with the fuse out, or a switch spliced in, the manual transfer-case will shift to 4lo, the rear AND front DRIVESHAFTS will turn, but the front axle won't engage correct? Messed up shift points is a non issue with the ZF-6, and besides I'll only be using this in reverse anyway to back up trailers and such. If there is any adverse effects like the computer setting codes and such, then I want to stay away from it. But if not, then I'd really like to set this up.Sorry Zorg, I kinda left you hanging:( Yes, you are correct. Most folks that have Allisons can just two foot the brakes. They don't understand that trying to back up a 30' trailer while constantly feathering the clutch gets old real quick!!! I pull the fuse all the time wthout any prolems.

I never went looking for the wire unfortunatly but I'll see what I can find.

dan

Think weight transfer. Backing up an incline the weight transfers to the front wheels of the truck. We have an asphalt boat ramp in TN that is wicked steep, in 2wd in reverse with 5k trailer/load the rears break loose real quick.
When we back down trans is placed in (N). With the extra trailer weight and torque of the DMAX the brakes dont like to fully stop. Forget 4lo down hill backing, very bad combo if you want to fully stop. Good for safety if the brakes take a crap though.
I am ignoring the 6 speeds and flat backing.
There is a post about reverse and 4lo limiting power because of drive strain.
SC

OK, I must be blind because I went to the fuse block under my hood today looking for the fues, and I can't find it.... :help2:

Zorg, sorry, It's in the left Instrument panel fuse block. Open the drivers door and open the little hatch. It's a 15A fuse towards the top. I'll get a pic as soon as the rain/snow stops:mad: I hate this weather!!!

Once again, I must be blind cuz I went and looked there too just for giggles and found nothing..

This is almost embarassing... just confirming, that is with the manual transfer case too?

It should be where Rattlewagon said. It's the 4WD 15amp fuse. It is the same for manual tcase. Fuse #7 I think.

Zorg, here's some pics for you. Now I know that where you are snow is an "occupational hazard" but here in Washington PA, snow on April 24 is something you dont see all the time! Last week I was sweat'n my butt off cutting down tree's in 85 degree weather!!! Censored Censored

Anyway, you and I have just about the same truck so the fuse with the yellow circle around it is what you want. I also think the color behind the fuse block to tap into for a switch is brown...
Good luck!
dan

On edit; Guess I should've left my front winter cover on :mad:

Beautiful, thanks Dan. I'll look into that tomorrow.

As for the snow.... I disagree, it's not an "ocupational hazzard" it's a way of life dude!!):h

We ot a total of about 5' this winter. Some places where the drifts were really high, I measured 7'. Only problem, it was to stinkin' cold all winter to REALLY enjoy it. We tried though. Just last week we got another 6" although that's finally all melted now and like you I'm sweating my arse off every time I go outside now.

Again, thanks a lot Dan!!!:cool2:

One small problem I just encountered. I was about to go out and do this mod, but found not one, but two brown wires. Both after the fuse in terms of current flow, and both turn "hot" when the fuse gets put back in. Of course both are not "hot" when the fuse is out. Does anyone know which wire is for the front axle? The top, or the bottom one. They are placed directly above one another in back side of the fuse block.

-Zorganov

On edit, Zorg, dont worry about the two wires,just combine them into one before the switch and branch them off after. It doesn't matter, pulling the fuse kills both anyway!:eek: Sorry, I'm not that smart!:o:



On way would be a single throw double pole switch and kill the power to both of them. I'll see if I can find out any info in the service manual.

You could switch before the fuse but I'm not sure I would do it.....

I've already got the switch I want to use, it's the same as all the other rocker switches I've got in the truck, so I may just put the switch in before the fuse, and put a 20amp fuse in before the switch (switch is rated for 30 amps). I realise the fuse in the block is a 15, and I would keep that there just for extra protection. What do you think?

Like in the previous post, pulling the fuse kills both anyway and because the two wires originate directly after the fuse I would cut the wires right after the fuse, combine them into one wire into switch then send one wire from the switch back to the two wires and let them split from there.

Here's a really bad schematic kinda showing what I'm saying.....

I know this is a really old post, but I figured I'd update you on my progress. After nearly a full day under the dash of my truck with my 12V tester, I concluded there were WAY too many circuts in that whole fuse block connected to that particular fuse. I had a continuity tester in there as well, and there's about a dozen different configurations I tried and none of them worked. What I ended up doing was taking apart a fuse and plugging the two ends into the face of the block and running a wire with an inline fuse to my switch and then back to the opposite terminal in the block. So far it's worked flawlessly!