alright how much vac am i lookn for at the cad? i have just enough that i can feel it with my thumb and when i take it off for it to go "tssk". it engaged into 4wd once after quite a few times of backn up and pull forward.

when i move the front drive shaft by hand i can hear a clicking in the t-case right where the shaft goes in, what is this?

 

the sound in the t-case when shifted to 4wd is the backlash in the gears or chain. normal.

the vac at the cad should be the same amount you can measure up at the manifold. approximately 15-20 inches and be fairly steady at idle. most gauges will have a green zone for normal range.

do you have a way to put the truck up on 4 jack stands so you can diagnose it safely.

 

yea i could do that, i was just shifting into 4wd with the front end jacked up and spinning the tires, and it wouldnt lock the shafts.

my other front axle u-joint peaced out while i was testing the 4wd, so how long b4 that side starts leakn?

 

it almost seemed to be locking in 2wd and unlocking in 4wd, and i cant find where zman said where the red and black hook up. red is right side right?

 

i don't know, i took mine off a long time ago. if it seems backwards, switch them.

 

ok, that's a valid way to do it. i thought you were driving around.

peaced? what does that mean. when one goes the other usually follows soon. only a matter of time.

 

my u joint peaced out, left the building, its all loose now. it doesnt feel like im getting 17" of vac at the cad like i am at the manifold, so that may be why its taking so long to engage

 

any things i should do when replacing the driver side u joint to keep from scarring the seal?

 

pretend the seal is made of glass. lift the axle as you pull it. grease the end when reinserting, and lift it over the seal. for the axle tube, i'm not sure which is best- clean it out, or leave it alone and don't stir up any dirt.

it doesn't make sense that your u-joint would go out while you're working on the other side... its a big hunk of steel that takes years to wear out. it turns all the time in both 2wd and 4wd. is it loose and clacking?

 

what's the vac measure
at the manifold ?
at the cad ?

for a test, you can run a temporary vac line from the manifold directly to the cad.
connect it to one side,
then the other.