So once in a while I'll hop in and start driving and on deceleration I'll hear a slight hum/almost grind from the transfer case. I'll stop, engage 4H, do the R then D thing and put it back into 2WD, do the R then D thing and we're good. Then sometimes after sitting, whether for minutes or hours it will do the same thing and repeat process and were good. Well today after work I had to really use 4WD, not just for fun...(snow). Everything seemed fine besides that I couldn't actually tell if it was in 4H...seemed like it was but at the same time wasn't. Stopped in a empty parking lot and 2WD was obvious, 4L was obvious...but with a noticeable whine that seemed a bit much and then 4H seemed like it but giving it heavy gas it spun the back tires and didn't feel like there was much pull from the front. Given I know the rear gets more power and I've never tried this thing in snow so maybe it was all good and I'm just not used to it. I did make it home safe and sound with no loss of traction, pulling, anything so I assume all was good. Until I was a couple hundred yards from the last stop light when it started to do the hum/grind thing..so I pull over and finish the drive in 2WD, which was fine cause the roads were clear after this point. Tested everything out at this little turn around down the road from my house and everything works besides the random (half) engage/disengage or whatever so..ideas? I've done some research and seen stuff about the chain, gear bearing, fork, front driveshaft slop/play, u-joints so no idea what to think or where to start...

 

Could be in the vacuum operated cad. There's lots of little annoying things that can screw it up

Check your linkage and all the vacuum lines running around everywhere

 

CAD would be where I would look first for 4x4 issues. Does the light in the dash come on, indicating 4wd?

Another common problem on these trucks is the snap ring that holds the rear output shaft in the correct place. It likes to fall off, allowing various parts to walk around, and grind on things that they really shouldn't. If you have a reasonably warm place to work, drop the rear drive shaft, pull the tailhousing off the t-case, and verify the snap ring is still in place. There is a better design retainer for it though. Transfercase saver. Much better idea, and simply won't fall off.

 

I'll have to have the lines, linkage and ring looked at. I don't have the time, place or tools for anything these days. As for the indicator light, pretty much no...it works, I know that cause it lights up randomly, but I'm pretty sure its never stayed on even when I know its in 4WD for sure.

 

as said, the 2 most common grinding sounds will come from the CAD collar (passenger side front axle) or the tcase rear snap ring.

for the indicator light - something that's easy- find the cad. passenger side front axle, rear side of the tube. plate/cover w/4 bolts. find and unplug the electrical connector on the drivers end of the housing. spray it out with wd40 or contact cleaner to get rid of mud, dirt, sand, salt, grime. with ignition on and a helper in the drivers seat, jumper the 2 wires in the connector. 4wd light should come on in the cluster. if not - there is a wiring or bulb problem with the indicator.

the cad grinding problem is usually caused by a vacuum leak. if you have a place to work, then its easy. verify vac on one line in 2wd and vac on the other in 4wd. if you have any vac problem at all, then the cad won't work right.
http://dodgeram.org/tech/repair/4X4/4x4_engagment.htm


tcase is a little more difficult. you'll have to remove the drive shaft and the extension housing from the t-case. if you do this, you need to have a new snap ring in hand, because it takes 15 minutes to get to where you can see it, and only 1 more minute to replace it.
how to here...
http://www.drivetrain.com/parts_cata...ml#Application
edit - you don't have to have the $54 replacement part. it's nice - but a $5 replacement snap ring is good enough.

 

So the transmission shop says its the vacuum motor and I believe he said a new one was $180 (although I've found cheaper online and will be checking the parts store after I post this haha) but given that price I feel like I should just buy the Posi-Lok anyway, right?

 

it depends on your ability to install it, and what you want.

it takes a little bit of figuring and patience to drill a big hole through the firewall, route the long cable, assemble the fork, and then adjust it. if you can do this yourself its fine. if you had to pay someone else, it could be expensive.

then as you use it, it requires an extra step to engage/disengage 4wd, unless you just leave the axle locked. i like mine, but some people might not like that extra step. i like the ability to use 2wd low for slow trail/bad road crawling.

http://www.pavementsucks.com/tech-article-29.html
https://dodgeforum.com/forum/2nd-gen...installed.html

 

I planned on having somebody do it and I'm sure he won't charge as much as the shop would so I'm not too worried about the cost. I'm not worried about the extra step either if it means some added security to the 4WD system.

 

Update: the Posi-Lok arrived today and once I get a hold of my guy, I'll have it installed. Anything I should know first besides that the template measurements are a little off, making sure alignment of the fork is correct or whatever else was in the two links that were posted that I may have missed?