Last year somebody told me there weren't any 16% grades around. This one is in West Linn Oregon between a residential area and the commercial strip. This is one street why I would like to have the front axle disconnect kit installed so that I could use low range when pulling a 12 to 15,000 pound trailer. If I had a manual transmission, I might be fine.

Edited April 11, 201411 yr by joecool911

There is on just down the road from me...

I bought a 12v normally open solenoid valve, mounted it to the firewall behind the air cleaner, and bought some vacuum line. Disconnected vaccuum line at the firewall where it heads down to the tcase and provides vaccuum for the 4wheeldrive actuator and ran it through the solenoid valve and then tied it back in to the tcase. Mounted a toggle switch in the cab and wired it up to the solenoid valve, and when I want to use 2wheel low I simply flip the toggle switch which interrupts vaccum to the cad and then shift the truck into 4low. I now have 2low.

 

If you would like I can snap a few pics so you can get a bit of a visual.

Edited April 12, 201411 yr by diesel4life

Yes, I get the concept. They sell a kit for around $175. Would like to know how to get the solinoid especially. Pics would be super! Thanks!!!

Yes, I get the concept. They sell a kit for around $175. Would like to know how to get the solinoid especially. Pics would be super! Thanks!!!

Going down a grade like that with a heavy trailer behind pushing I would want 4 wheels braking not just 2.

4X4 low range for me in that instance especially if a bit moist or wet. The only spot I would like a 2wd low kit is during heavy backing situations where most trannies fail by getting deep fried.

Pic of the solenoid valve. I made a simple bracket out of 1/2" conduit, flattened the ends and drilled holes though them for mounting and used one of the bolts for the hood hinge to secure it. Just one of several ways to mount it. I came out of the valve with barbed fittings to make the connection to the vacuum lines simple.

Two way toggle switch to actuate valve. I mounted it down low and out of the way as I really don't need it very often. It is mounted under the cup holder.

This is where the vacuum line comes out of the manifold and drops down to the tcase and supplies vacuum for the cad. I disconnected it here and ran it through the valve and then back down to the tcase. The valve is a normally open valve so under normal circumstances vacuum flows through it so when I shift into 4wheel drive high or low everything works as normal. If I want 2low I have to flip the switch first to interrupt the flow of vaccum and then engage the tcase into 4low.

It's a very simple set up, probably not as fancy as the disconnect kit you can buy but not a bad alternative if your on a budget or you just want to save a few bucks. I bought the valve from a local industrial supply company but I know they are available online as well. Around $40 for the valve, $10 for a toggle switch and a few feet of vacuum line along with some wiring and your all set.

http://www.dudadiesel.com/choose_item.php?id=2W04008KN

 

This is very similar to what I have but not exact. A few things you should look for are 1) a normally open valve configuration, 2) a continuous duty solenoid will give you longer service life but is not an absolute must, and 3) a 2 way valve will open and close with minimal pressure/vacuum. Some valve configurations require pressure to open so read up on the specs before you buy anything.

Also most solenoids come in either 120v or 12v so make sure you select a 12v solenoid.

Edited April 12, 201411 yr by diesel4life

Going down a grade like that with a heavy trailer behind pushing I would want 4 wheels braking not just 2.

4X4 low range for me in that instance especially if a bit moist or wet. The only spot I would like a 2wd low kit is during heavy backing situations where most trannies fail by getting deep fried.

 

I ALMOST found that one out the hard way when I first got my trailer! Whew!

Okay, also, I'm not sure if this is a related thing, but I put the truck in 4lo to pull a utility trailer loaded down and truck too, to go hunting in the mountains. Alot of slow driving in 1st, 2nd gear. So like I said, I had it in 4lo, because I quickly found that the lack of lockup created heat issues for the tranny.

 

Upon descent from the mountain in 4lo, it almost felt like I had a 2nd gear lockup? I know thats not true, but I let off the fuel peddle and about 2 seconds later, I immediately starting slow down very quickly. Can someone explain why this is so?

I believe you probably felt the extreme low gearing from being in 4low. You may very well have been in third or fourth gear and had lock up? I know if I hit the OD button so my trans stays in third gear while in 4low I will hit lock up in third at less than 15mph.

Just be careful using 4low on any paved surface as it is very hard on the drivetrain. I tend not to even think about using it unless I am off the hard pan.