lobukbuild

sorry thot you were my statement. however by unplugging the switch at the front axle will turn the lite out but have no effect on anything else. and correct on unplugging the case switch will disable the add by thinking its in 2wd. didnt think off doing that as a diagnostic test.we should include that basically if his lite stays on problem could be in add system.if lite goes out it would probably lies in the case. i usually check vac at the diff for operation and apply vac to the actuator to test for sticking .looking back were both saying the same thing, unplug t-case and itll cause the add to disengage and when it disengages the switch at the diff will turn the lite out if its working properly

scope103

If you are unable to turn a front wheel with it jacked up, then BOTH your transfer case and your front differential remain "engaged." (I don't see where you mention whether you have locking hubs, but since you talk about the two vacuum lines I assume you don't.)

I'm beginning to suspect that your transfer case has "always" been unable to shift out of 4wd, and you have just been shifting the ADD (via the transfer case shifter) in and out of engagement. When your cousin worked on your vehicle, he may have just bumped into any part of the ADD control, causing it to stay in "engaged." The way to check that is to see if you have vacuum (with the engine running) on one of the two vacuum lines to the differential, and that the vacuum switches lines when someone moves the transfer case shifter. (You can check for vacuum just by putting your thumb on the end of line.) If the vacuum works properly, you have a problem in the differential. If it doesn't work properly, all you need to do is work backwards toward the VSVs.

For what it's worth, I have no trouble shifting in and out of 4wd at speed, or at a dead stop. None of this backing up. I always thought that was why I had ADD.

lobukbuild

never thought of using that for diagnosis. unplugging the t-case switch will disengage the add system and then the switch at the front diff will then turn the lite out if its working correctly.
that switch at the front diff had gotten smashed on mine once and the lite wouldnt work at all. i hated having no lite, and constantly checking the shifter to make sure what position it was in.
any way my bet is a broken shifter and or rail/actuator shaft. if you need parts i have the rear half of cases left over from building dual case set ups.

CamPor

Some more info on my dilemma.

My 4wd shifter smoothly shifts into each 3 positions (2high,4high,4low) a J pattern.

My 4wd light has never worked, it actually blinks real quick when I shift from 2high to 4 high, but doesn't stay on.

It easily shifts from 4 high to 4low.

Im not sure where its "stuck" whether it be on the axel side or the transfer case.

It is has the ADD system.

I really do appreciate your time and patience with this issue im dealing with.

another thing. I went to the dirt road yet again a few minutes ago. i was rolling at maybe 10 mphand when i went to shift it to 2high i heard a odd sound. the sound sounded like a thick tire tread on a freeway.

^^ maybe useless info but im trying to give you anything i got

CamPor

I found out by removing the front drive shaft its not stuck on the t-case side its on the axel side.

now were getting some where

JasonYota

iTrader: (1)

If the transfer case is able to shift into 2wd, the truck would be in 2wd, with the front axle locked in. Not what you were describing in the beginning.

CamPor

I apologize if I misinformed you in anyway. a lot of this info I have on the truck is out of one mouth, and out of my fingers. I know very little about this subject as im sure you can tell.

So now that we know the axel is locked up, and not a t case issue, is it pointless to leave the drive shaft off?

JasonYota

iTrader: (1)

Yes because it's the same as driving with manual hubs locked. With your transfer case shifting into 2wd there shouldn't be any binding while driving on pavement.

CamPor

Thought so.

Ok, I will need to continue to do more reading/searching on what to do next.

My uneducated guess is im better off with the front locked up, opposed to my tcase not releasing 4wheel.

It just seems like less of a job now.

lobukbuild

the mechanical parts of the ADD in the front axxle are pretty simple to understand. 2 vacuum lines operate a fork that moves a gear back and forth to engage/disengage the front axle shaft. check for vacumm at the 2 lines while shifting in and out of 4wd with the shifter while the motor is running.

CamPor

I am going to go over all the lines tonight or tomorrow depending on time.
I found a nice diagram for vacuum lines as well.

I did want to attach a link for you guys so you can actually see what youre helping me with.
I love the damn truck no matter what I have to fix/deal with.
so far its been a cracked brake/clutch bracket (wasn't too bad), and a blown head (had my cousin handle it, too much for me).


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