I recently lost 5th gear in my truck and fixed it myself. Everything works great now except that my 4wd will not lock in. Locks in low range and everything fine at the case just won't lock the front in. The 4wd light won't come on either. I am almost positive I hooked all the vacuum lines and connections back right when I put the transfer case back in. It was kind of acting up before though as it would take while to lock in. I would have to drive a little ways before it locked. I am not at all familiar with how the CAD system works. I would love to put manual lockouts on it. Is this possible? Any ideas on what could be wrong? Thanks.

 

It is possible to put manual lockouts.I believe it is Dynatrac that make a conversion kit. A cheaper solution it the Posi-Lock system. I don't know alot about it, but Rick (Txdiesel007) has it, likes it, and knows more about these trucks than I do.

As far as the problem you are having now, double check the vaccum lines. It dosen't take much for them to cause it to not work properly...

 

You might have a busted diaphragm in the CAD.. the thing that drives the collar over to engage it with vacuum. Ive heard those fail a bit.
I second the posi-lok idea. Much better to make it manual and be done with it. I had a vacuum system on my last truck that was pretty problematic as well.

 

Ding ding,

u are correct nick, Lockouts? well they are expensive unless you can get an axle from a ford pickup truck. A posilock is ur best bet, Believe u me, I tried to fix the vaccum lines..

a good place to start might be at the top of the Transfer case, there is a four connecter prong that connects to the top of the T case, accessibly from the drivers side, You might wanna pull that off, and go ahead and clean it out, see if that helps.

Also take a good look at your vaccum lines. Theres two of them by the transfer case, if they have oil in them or are caked in oil, mud, dirt, or whatever they will not function. You can find replacements at O Reily autoparts in the HELP section. I paid like 4 bucks for a whole bunch of them.(the little connecter sleeves i mean)

Thirdly, look above your fuel filter. If you have changed it and have lost a hose connection, that in turn can affect if your 4WD engages or not. I personally zip tied all of my loose ends when i found out that i lost my vaccum pressure. If one connection is off, seems to me that the 4 wd wont work properly.

IF none of those fix your problem, then you need to start lookin at the lines closer to the CAD, one creates vaccum to pull the collar off when u engage 2wd, and the other pushes the collar onto 4wd, if you can shift and feel vaccum in 4wd and in 2wd (not certain bout how many lbs of vac pressure tho) then your problem lies in the CAD..

The CAD can get oil in it, or get rusted out. Both Kawi and Displacedtexan are right about what they have said. that CAD is a pretty wimpy thing if you ask me..

Still need further persuasion about a Posi Lock kit? Installation tips, and what not? Read the following post. I guarantee you will love ur posi lock if u chose to buy it..

https://www.dieseltruckresource.com/...ight=Posi+Lock



here is a pic of the final product... More info available in my gallery pic...

Hope this helps!

Rick

 

Thanks alot guys, I will definately be gettin a posi-lock. I have used "2 low" many times since my cad has been out and comes in handy. Especially when backing my boat.