Ok fellas, I have been searching both the truck and the forums for anything that can help with no luck....

The problem I have a terrible vibration that feels like it is in the rear or driveline. It happens above 10mph, comes and goes. I hit a bump/pothole and it vibrates until I hit another one.... Most of the time. There is no regualrity to it at all. Sounds/feels fast like a fast basketball dribble. Truck tracks straight and I do not feel it in the steering wheel. Also, If I engage the transfer case (with hubs out), I do not get the vibration.

What I have done.... Driveshaft retubed and new U-joints. Shocks are old but tight, All driveline componets are tight, Tires balanced with no unusual wear. Springs are OK, no broken leafs or U joints.

Yesterday I went to my buddies garage for help. We put it on the lift and opened the fill plug on the transfer case and fluid (quite a bit) came gushing out..... Hmmm... It looked kinda nasty too, not nice and red like most T-cases I have seen. Tranny fluid has been low, and now is completly off the stick.... I am guessing a seal between the trans and T-Case is bad and letting fluid go one way...

Drained and refilled T-Case, topped off tranny and went home. Vibration still there but not nearly as bad. This morning vibration back to horrible. Forgot to check fluid level will do that in a few minutes.

Sorry I am a bit winded here but this is driving me crazy........
Thanks for any help....

 

Oh, it doesnt change with throttle or brakes, and if its vibrating and I shift to neutral, it remains the same and acts the same if I hit bumps/potholes and the wheel bearings are tight......

 

Its either one of 2 things. The U-joints in the drive shaft or the carrier bearing. To check drive shaft try twisting it, you shouldnt have any play at all. The most common one to go bad is the rear most U-joint at the pumpkin. If you have a carrier bearing just push up and try to wiggle the drive shaft near the bearing, shouldn't move in its housing. Keep us posted!

 

That was my first thought.... Unless I got a bad u-joint, its only got maybe 1000 miles on it, and I have no carrier bearing. It is easy enough to switch out again, but all the needles were in the caps, and it is properly lubed....

 

I can't tell what it is. Since it does it in neutral it eliminates the engine, but nothing else. Everything else from the trans back is suspect.

 

Thats what I was afraid of.... I am gonna tear out the driveshaft and check the u-joints since that seems to be the number one suspect, and its easy enough to do.

Mark, is there a seal and the tail of the tranny to t-case that is causing this leak, and is it possible to have "to much" fluid in the t-case....

thanks all

 

Is it possible the timing got off when you had the shaft retubed ?

 

Yes, there is a seal on the tail end of the trans that can fail and overfill the transfer case.

 

Well, dropped the driveshaft and found that the rear U-Joint had a tight spot or two. Changed it out, and still have the vibration. The driveshaft is in time.

The thing that gets me is when the hubs are locked in the vibration is greatly reduced. Also, with hubs out and the t-case engaged the vibration is greatly reduced. I keep thinking that its gotta be the t-case...