I have a 1998 dodge 1500 4x4, I bought the truck from my brother in January, long story stort when he had the truck he snapped an axle so instead of fixing it he just replaced the differential, keep in mine this happened in the summer... that winter he had body work an paint done so he never drove the truck in 4x4 after the diff swap (4x4 did work before the swap too). Now I own the truck an with winter on the way I do what most guys do, check fluids, breaks, 4x4 ect... so I go to put it in 4x4 an its binding up BAD!!! turns out the my brother installed a 2wd differential 3.92 gear ratio, its supposed to have a 3.55 gear ratio.. so I fix the rear diff. Ratio and it still binding up. It goes into 4x4 hi perfectly an when I put it in drive an let go of the break it moves 8-10ft an the truck comes to a stop till I give it
gas and it moves a few inches and then CLANK CLANK!!! Its directly under the drive seat. An when the truck is parked in 2wd I CAN NOT spin the front drive shaft by hand. My question is what do u guys think has happened?? I've been looking to find a rebuild kit for my transfer case not having any luck on the internet. If anyone has any info on company's or what to watch out for on rebuild kits please let me know.

 

First thing I would do is pull the front diff cover and see what's going on inside there.

 

well sounds like u might have a vac line clogged if its not unlockin the front shaft. id take the diff cover off, put it on jacks, put it into 4x4 make sure it all works and see if u can hear the clunk. put it into 2wd and see if it unlocks the front shaft, if it doesnt take the CAD off pull it straight out and try not to move nothin side to side when u do so u can see the position the collar was still sitting in, if its still sittin over both shafts then u know its not shifting it over, then id check the CAD and vac. have someone engage the 4wd and then back to 2wd and see if the fork moves or not, if it dont then u know the vac line is clogged or broken, or it could be the vacuum switch. just a place to start.

 

I doubt it's the t case. Something is wacky in your differential.

 

I thought the t case was ok to, because when I fixed the rear diff I took the front drive shaft out and put it in 4x4 an drove it around an the t case made no noise... I would think if something was broke or out of wack it would do something. It only binds up when the fwd drive shaft is in. I replace the metal vacuum lines already because they were rusted out after I fixed the rear diff. I noticed there wasn't a "MAIN" vacuum line on the CAD I so did some research an I went to the auto parts store an got some rubber 3/8 line I believe an ran it to the intake (had an open spot on the driver side of the intake). Did I hook this up wrong? Can anyone send some pics of how there vacuum lines are hooked up? Im hoping its not the tcase either. Ima try to get the front diff cover off tonight an check it out. An i dont know if this helps but my 4x4 light is on too an its in 2wd.. Thanks for the help so far

 

Wouldnt hurt to pop the CAD off and have look in there. Im not a big fan of the vacuum operated CAD.

Proper vacuum routing is in the FSM. Grab it out of the DIY section. Its a free download. Good thing to have anyway.

The t case is basically a couple gears and a chain. Pretty simple really. And believe it or not they are pretty tough.

 

http://dodgeram.org/tech/repair/4X4/4x4_engagment.htm

As been mentioned...insufficient vacuum. Need vac to keep front axle disengaged and need it to engage it. The 3/8" line is too large.

The source starts on the passenger side of the intake manifold (typically). The line runs down the back of the engine on top of drivetrain into a harness. A portion goes off to the switch in the transfer case. Another portion goes to the cross member to connect to the metal lines you mentioned replacing.

If you have jackstands and you don't want to take off the front cover yet in order to test the CAD, then follow these simple instructions. This way you don't have to worry about drain/refill fluid...yet. Also hit the bolts on the CAD plate with penetrating fluid now....just in case you do need to open it up.

Block the rear wheels
Put one tire or whole axle up on jackstand.
Shift tranny to N
2Hi -- spin one wheel and other should not spin
4hi or 4lo -- spin one wheel and other spins opposite

Can also test with front driveshaft by hand, like you mentioned before.

Someone double check me, just in case.

 

The cad may very well be stuck but that will not cause the binding he has going on, as posted pull the front diff cover and inspect the spider gears, ring gear all of it.

 

Late night at work... didnt get to tear into it, maybe tonight if all goes well.

Im going to have my buddy come over an just copy the way his vacuum lines are hooked up, dont know why I didnt think of that the first time... I noticed no one has really said the t-case is trashed or somethin broken, but it seems like all the noise is coming from there?? I know I'll have narrowed it down alot once I check the front diff... just a thought i had a buddy "mechanically minded" watch under the truck while it 4x4 and he said "I want to put my hand on the tcase but I'm scared its goin to grenade"

 

Im goin to try to post a video on YouTube so everyone has an idea. It will be later tonight after work