truck wont go into 4 wheel drive!
 

weel today while pulling a friends truck out, I went to put the truck in 4x4 and it wouln't go in!!! what should I be check first? with winter coming up i need to get this thing fixed!

casey

I always switch form F to R or R to F to help it engage, seems to help some but my light doesn't work so I try to double check, where you trying 4H or 4L???

Check the vacume lines going to your front dif. If you havnt had it in 4wd in a while they may become loose or clogged. When I bought my truck the 4wd didnt engage because the previous owner pretty much never used it. It ended up being like a 15 dollar hose or something like that to fix it.

mine wouldn't engage either and I crawled under to take a look and found two lines ( red and a black one), that I am asumeing is the vacum lines talked about above, that were hanging. I slipped them back onto the metal lines and it worked. Same thing happened to a buddies truck and it was fixed the same way.

Any Luck?

My truck was giving me problems this morning for not going into 4wd. Have to look into it later on today.

no i cannot find which hoses it would be? none look to be disconnected... i can i tell if they are clogged?

casey

They're vacuum lines: all it takes is a split in one to keep it from engaging the front axle.

Randy.

Do a search for CAD and 4WD and you will find a plethora (or cornucopia since it is the Thanksgiving season) of information on it. The left line on the CAD sucks the diaphram into 4WD and the right one sucks it back into 2WD. If your light isn't on then you ARE NOT in 4WD. That light is connected directly to the switch that is poked by the CAD arm. The light is an LED so it rarely fails (and if it does, then the whole dash light panel has to be fixed....)

I though all of the red lights on the dash were LED's, while the bottom row are all little tiny light bulbs?

And as far as my truck goes, while driving home tonight in the snow I decided to try and put it into 4wd. It goes it and actually locks in rarely, all the other times it wants to, but gives up. Sometimes the 4wd light will just sit there and flash. And other times (rare) it could be in 4wd, but the light doesn't come on. I'm guessing that this is a CAD issue, can't blame the almost 10 year old part though.

Found my problem in regards to the 4 wheel drive problem.

I took my CAD out and checked that over, thing was fine. Left my Vacuum lines hooked up and had my coworker move lever from 2W to 4W to watch the CAD move. It barely moved into 4WD mode, however once lever was put back into the 2WD the finger moved back into place with good "force". Took off my lines and the red had good vacuum (in 2wd), once switched over to 4wd there was no vacuum in either.

So I worked my way back to the the cross member underneath the transfer case where the Steel Vacuum lines meet rubber again. Took those fittings off there and both red and black had good suction. I left them off, took a blow gun and blew air through the Black line....ended up finding a pretty big leak where the steel meets the rubber (above the CAD on the frame rail). Cleaned, re-fitted and zip-tied rubber fittings back on and 4wd now works like a charm! (4wd light also works now since the CAD is able to move all the way to 4wd position).

Here's what the service manual says about the light:

An amber
lens behind the cutout in the opaque layer of the
overlay causes the “4WD” text to appear in amber
through the translucent outer layer of the overlay
when the indicator is illuminated from behind by a
Light Emitting Diode (LED) soldered onto the instrument
cluster electronic circuit board. The four-wheel
drive indicator is serviced as a unit with the instrument
cluster.

To me this means you have to replace the whole cluster when one of the lights fails.... Most LEDs are rated at something like 100,000 hours, so hopefully the truck will fall apart before this happens.