Hello all,
My truck vibrates at 70mph and you can feel it really bad when you are holding onto the transfer case shifter. It also does it when ypu are slowing down between 35 to 30 mph. When you take off it makes a small ratcheting noise near the transfer case but you can't hear it when you go faster because of the exhaust noise. When i let off the accelorator and then reapply it it make a clanging noise near the front drive shaft where it mates the tc. Could it be a u joint, the tc chain or a maybe a gear? The tc is full of fluid and has never given me any trouble. Any inputs would defenietly help. Thanks in advance!!!

 

It could be a U-joint or a case bareing. Pull front shaft off and check U-joints because if its siezed it may very little play to see of feel. I had a rear joint like that took it to dealer twice and they couldn't find it, guess the redish orange splatter all over box bottom and fuel tank wasnt a clue. When you have the front shaft off make sure everything is secure and take it for a short drive and see if it still does it. If in 2w drive no noise then try it in 4w drive if noise comes back then its in the T-case. Also make sure nothing has worked it way loose and doing something its not supposed to.

 

check the bolts that mount the driveshaft also

 

Almost guarantee it's your front drive shaft.

Jeff

 

Have you ever had the drive shaft U-Joints changed? At 217K miles on your truck, I would bet the POS stock lift pump sitting on my workbench that this is the cause of your vibration. Like others said, sometimes they can be bad and still not feel "sloppy." Your scenario was the same I had at 125K, but vibration happend at 45-50 mph, right after TC lockup. Chased that one for a few weeks before replacing u-joints, which in every repect appeared to be in good condition.

 

Thanks for the info folks, I have never replaced the front U joints in this truck. My first step will be to replace them and go from there mean time i will do all the above and see what happens. I will be converting to NV4500 soon so if that does not work then durring the swap tranfer case will be thouraly inspected. More to come!

 

Changes the front u joints and inspected the rear while i was under there. The looked like the came from the sand in Iraq. Changed them out and took away the problem. Funny how the rear ones are less than two years old and the ones with over 217k were still good.