The one (and as of right now only) thing I don't like about my 4wd is that I don't k ow how the system works. I understand that it is vacuum controlled and I think that there is vacuum applied to be in 2wd and vacuum is released to allow the 4wd to kick in.
What I want to do is be able to turn the selector switch to 4lo but not engage the front axle. This works great for backing trailers, especially in uneven ground.
I had this on my last truck, 2001 Ram, and it is great.

Anybody have an idea how to do it? Or where the vacuum line(s) are that control the front axle?

Thanks!

 

The vacuum lines go into the top back side of your front hubs. I woudlnt disconnect them cause that will cause stress in the entire system because it will be constantly sucking air trying to unlock the hub's. The iwe's are used to lock in the front CV axles to the hub. The front diff still has to be engaged I beleive by the transfer case as well when put in 4wd in order for 4wd to work.

 

There's a solenoid that controls the vacuum to the front hubs. I think it's near the brake master cylinder. I guess you'd have to hot wire or bypass it somehow to get the vacuum to the hubs to stay on and keep them disengaged.

 

Thanks! I will search for it.

 

I found my answer.

https://www.f150forum.com/f72/front-...-range-281765/