So I did some work on the old dodge ram 1500 5.9l , changed out drivers hub , upper and lower ball joints, still noticed a slight rumble when the wheels are perfectly straight. Happen to notice a red wire broken. Turned out to be the 4x4 transfer vac line( this would explain error code small vac leak). A little later noticed another vack leak but this was a large one. Looked and noticed that main vac line that has a rubber plug with 4 lines attached was off and dangling. Prior to I noticed shifting in/out of 4x4 the light never came on in the dash for 4x4..
so i fixed the broken red vac line for the actuator and put the end 4 prong plug on, I am assuming from the 2 notches it only can go on one way . No vac errors on dash. But right away in 2 wheel drive the 4x4 light is on shift it to 4x4 and the light goes off. When driving it and shifting into 4x4 no big issues , when i go into 2 wheel drive there's a loud RRRRRRRUMP sound with a shake. Best way to descibe it is, imagine a giant led pipe getting dragged across an old washboard during the GGGGG sound and then the ump sound is when it feels like it clicks into place.
I thought maybe I reversed the red and black actuator vac line giving the reverse 4x4 on the dash. So i switched them and the 4x4 signal is correct and didn't really notice a bad sound. But tracing the red and black vac lines from where they connect to the steel lines then back to red and black tube lines before going into the actuator I see I had it right the first time. . So put them back and still have the reverse 4x4 light and a heavy Rrrrrump going into 2 wheel drive.
before I noticed the vac line ls off I never a problem with 4x4 light and shifting gear, occasionally I would get a little clunk shifting 4x4, but nothing like this.
I did look at the 4x4 actuator shift sensor and seems ok pushes in and out and not rusted , I know that doesn't mean squat, also read that it could be t-case positon switch.
But it's the shifting into 2 wheel that scares me any idea whT I need to look at or suggestions.
thanks, in advance
Brendan

2001 Dodge ram 1500 sport 5.9L 4x4
200,000 klm

 

You need to switch the vacuum lines for the cad. Either at the cad, or, back at where they hit the metal lines by the t-case. The funky noises is the front axle trying to engage without being under power..... so, yeah, some gear grindage is happenin' there.

 

See i thought at first I maybe switched up the red and black vac lines, but if go and start from the actuator ( not sure if I have that part correct but the actuator is up towards the front where your 4x4 switch is and the red and lack lines end.) and follow the red and and black as they come of the rubber connecter then go into the steel lines back to the where the have rubber connectors ( these connections are in my photos) that would mean I need to go from red to black and black to red basically from my actuator to the CAD.

does seem like a normal thing or maybe some work done and the line corsair were changes.

 

Look at the rubber fitting that goes on the cad, The red and black hoses i believe are molded into it. Then follow them back to se if you got them switched. Also you may not have enough vacuum to pull the actuator out of 4wd. Check the vac at the fitting by pulling it off the cad and checking it with your finger.

 

I've seen that diagram a lot, so if I pop off the rubber connection where the rubber goes into the hose in my photos, and the red should be for 2 wheel , I should have suction on that hose . In 4x4 the black should have a suction or vacum on it. ?

I'm sure I read in these diagrams and videos the red tube is for 2 wheel and black for 4 wheel.

 

This may sound silly, but without putting the truck on a hoist can I physically tell of my truck is in 4x4 or 2 wheel, I can tell I'm the winter by the way it slides in the rear on ice nor snow but that time is gone.

 

You are over-thinking this. Simply switch the two lines where they hit the metal lines back by the t-case, and you will be all set.

When the lite in the dash comes on, that means the passenger side front axle is locked together, so, if the t-case, is in some flavor of 4 wheel drive, and the lite is on, you got 4 wheel drive.

 

Ok so I checked the vacuum and both red and black have suction they cling onto my finger pretty good. Red is 2 wheel for sure.
what I did notice is on a video of a 2nd gen dodge cad 4x4 this guy's plugs at the actuator ar inverted to mine so his black is on the left and mine is on the right. If you look at tge furst photo ( from the video his red and black cone down on the plug whereas my plug faves up.
does anybody know for sure if the black goes into the leeft hand side of that round disc shape part on the actuator?

Photo from video

 

My truck

 

Now I tried putting the plug they way it is in the video (i know this is no different then swapping the red and black at the CAD) and the 4x4 light Ines up with my gear and no RRRRRUMP when going into 2 wheel, buuuut .. when i go into 4x4 seems ok driving straight.
when I turn the wheel left I get this knocking noise (posted recording)
if I turn the wheel right I get the same noise but some of the tires are skidding , like when your driving but a wheel or two is stuck or the brake is on ? not sure if it its one or more tires but the trucks slows down and you can feel it skidding or the tire{s} dragging on the road.
any help would be great,