I have a 2000 2500 4X4 long bed. Yesterday I engaged the four wheel drive and noticed a ticking(two pieces of metal touching) sound from under the truck that gets quicker when speed increases..... but it doesn't make that sound in two wheel drive. Today I put it on jack stands and tried to replicate the problem but couldn't and since I couldn't I don't think it is coming from the transfer case. When I got off the jack stands I put it back in four wheel dirve and it made the same noise.

Maybe coming from the hub?
Perhaps the axle?
Front diff?

Anyone else had this problem?

 

have a look at all the assorted u-joints in the front drive train, particularly the front u-joint in the driveshaft. With the truck in 2wd, crawl under there, grab ahold of it, and give it a shake. If the joint is bad, you will know.

 

Maybe the carrier is picking up some metal chunks and spitting them at the diff cover? other than that, beats me.

 

I checked the u-joints on the shaft and could not get it to budge nor did I see any wear.

 

would ball joints cause that noise?

whoo 500th post

 

if it only does it in 4wd, then its got to be parts which only turn when in 4wd, which is the t-case front output, the front drive shaft, the ring/pinion, and the passenger side inner axle.

i still think its the front drive shaft u-joint. its a complicated double carden thing.

as a test, you could remove the front drive shaft, and engage 4wd. this will engage the t-case and lock up the front axle (4wd light on). this turns 2 of the 3 rotating pieces. if no noise - then its drive shaft. and while its out you can fix it

 

duh. i really need to think before i speak (type)

 

I will try to take the drive shaft off today and see what happens. I would love for the u-joints to be the problem but I have a bad feeling that it is going to be more involved.

 

it definitely sounds like U joints to me.... I know the front ujoints are always turning regardless of 4X4 or not, but the actual load on the ujoints when in 4X4 could very likely cause this noise. Do you notice a difference when you turn the wheel? Usually bad front ujoints will sound a lot worse when the wheels are turned...

 

+1 on the steering u-joints, I had the same problem this past winter and it was the drivers side that was worn.