71Cuda

I picked up an 05 2500 a couple of months ago. Last week I had to pull a friends exploder out from somewhere it never should have gone. When I did it I put the truck in 4 high to pull. The front hubs didn't sound like they're fully engaging. There was a clunk every few seconds but the front was pulling and the 4WD light was on on the dash. When I got home I rolled under and took a look and all I could see was what I think is a vacuum line coming off the transfer case and running along the side of the trans was hanging down and had rubbed through on the front driveshaft. I assume it's a vacuum line because it's 3/8ish and has a plastic piece in the end with a loose plastic cap on it and it goes into the transfer case beside an electrical connector.

The truck is 5.9L with 4 speed auto, and the floor shifter for 4wd. I haven't done anything to diagnose the problem yet, other than fixing the worn hose and googling the problem.
Everything I found with google was for late 90s Rams and it was always a vacuum issue but I didn't find anything about 05s.
I'm planning on jacking up the front end and spinning the tires in and out of FWD to see what happens, but I'd like a few ideas what to look for before I start playing.

jtamulonis

that hose is the vent line for the transfer case. it has nuthin` to do with 4 wheel drive. don`t know `bout the 4x4 problem. I`m not sure if your truck has the front axel disconnect ( vacuum or electrical solenoid on the long side axel housing) or is a constant running axel like the `06 dodge.

71Cuda

I'm not sure either. This is the first 3/4 ton I've had so I know very little about it and it's my first diesel so I'm on the lost side there too.
Here are 3 pics I took. The back side of the long axle shaft, front end of the front driveshaft and a hose that I just noticed going into the top of the case.



I don't know if those will be any help.

rockcrawler304

Pic 3 is the axle vent tube and the plastic cap on the end should be placed as high as possible to keep water and debris out.

You axle shafts are always spinning. The transfer case is where the disconnect is. Which means that when you are driving in 2WD your front drive shaft and axle shafts are still spinning but with no power applied.

If you were hearing clunking from the front end it could easily be the axle u joints. They connect the axle shafts to the hub shafts which allows the tires to turn. If that is the case you need to replace those.

71Cuda

I'll put the truck up on stands tomorrow in 4wd and see if I can get it to make the noise so I can find exactly where it's coming from. The vent tube runs to my inner fender so it's well away from water unless we get hit by a hurricane

71Cuda

I got the truck up on 4 stands today with it in 4 high.
When I spin the drivers side tire either way, the front shaft doesn't spin and the passenger tire spins in the opposite direction.
When I spin the passenger tire forward, the front shaft moves and spins the back tires in the same direction, but the front drivers side only moves intermittently. When I spin it backwards, the front shaft doesn't moves but the left front moves at the same speed as the passenger side. It takes a couple of inches of movement on the passengers tire before the drivers side starts moving.
When I spin the back drivers side the back passenger spins in the opposite direction and the driveshaft doesn't move.
All this was done with the truck in 4 high in neutral with the engine off.
I don't know if the results would have been any different with the engine running.
I couldn't make the clunk happen this way, but the original sound reminded me of of worn bicycle gears when the chain slips a tooth catches the next one. The feeling in the truck was about the same too.
If I rock the front shaft back and forth the front passenger tire and rears both rock the same as the shaft but the drivers tire only rocks forward not back.
When I can get a full rotation out of the front shaft all four tires move the same forward but the drivers side doesn't move when I spin it backwards.

verdesardog

hmmmm sounds like you might hve a bad front differential...

71Cuda

That's not what I wanted to hear. The truck only had a 30 day warranty.

Sent from my SAMSU..........ahhh zombies are trying to eat my brains

rockcrawler304

Don't worry about the back tires.

Your diff might be just fine.
You can pull the front cover and do a quick inspection of the gears. (the gasket is reusable when you put it back on) Use brake cleaner to clean everything real good. Look for chipped or broken teeth on both ring and pinion.
The rotation moves you describe are pretty normal. You have an open front diff and with both front tires off the ground it can do what you describe. If you only jack up one side at a time and rotate the wheel the front drive shaft should spin. If you have bad u joints you may not be able to get them to pop or clunk unless they are under a load. Without a load just make sure to have the wheels turned to full lock position, this MIGHT make it happen.

Hope this helps!

71Cuda

I'll see if I can get under the truck today to pull the front cover but it sounds like the end of the world is rolling in so it might have to wait until tomorrow.
Will the front cover come off without messing with the front suspension? It looks a little tight in there.

rockcrawler304

YES
It is a little tight but it does come off without messing with anything else.

71Cuda

It's been raining pretty steady here for the last few days so I haven't been able to get back under the truck, but I did some thinking.
Right after I bought the truck I played musical trailers in my yard and had the truck in 4H with no problems. Drove an hour to San Juan and back a dozen times at everything from 50-80mph in 2wd to see where I got the best fuel mileage with no problems.
Went to check out an old acreage and put the truck in 4H with no problems, but then I hit a VW swallowing pothole in the field and the diff started making noise then.
My next trip to San Juan I had my first encounter with death wobble.
Could these two things be connected?

steelblitzkrieg

This may be a dumb question but I don't know how familiar you are with 4WD so humor me...

Were you on dry ground with wheels turned at all?

If so, it's normal, it's not good for the system, but it is normal.

Does it clunk driving in a straight line?

71Cuda

I've had 1500 Hemi trucks, but this is the first 2500 with a full diff on the front end.
As far as I remember I was on loose packed dirt the first time it happened in the field and I was driving straight and turning.
When I was pulling the Exploder out of the ditch I was on pavement or concrete with the wheels straight.
If I remember correctly it doesn't make the sound when it's coasting, but gets noisy when I touch the gas pedal.
It's supposed to rain tomorrow so I can't work or work on the truck, but I'll get out and refresh my memory about what it;s doing exactly.

Green_Machine

I think your diff is fine. you can't tell what is going on inside the diff by turning on e wheel and then the other unless it is a locker, which the front is not.

If you wanted to do anything, turn the shaft going into the front diff and see one wheel turn, apply a bit of traction to it and the other wheel should turn.

You have a bad ujoint on a wheel or an the shaft 99%. If it doesn't make noise while running/turning I would wait until it does, then do both sides. It will need load on it before it will make noise, most likely.

Chay