A few thou. miles back, (shortly after getting my truck back from it's first visit to the dlr. since I bought it...hmmm.) I started feeling a very noticeable vibration in both the loud pedal and the steering wheel. At first, it was only on accelleration or under load. The sensation is as if I am running over some ribbed concrete or kinda like I am driving with studded tires on dry concrete. Coasting, there was no vibration. I ran different tires that I know are not the problem.
It gradually worsened, and now the vibration is there even on coast down and when I get on it, you can hear the hum and it slighly rattles the whole truck, so today I slid under and wiggled both driveshafts, inspecting the U-joints. All seemed good, so I pulled the front shaft, trying to isolate the problem. This allowed me to spin the wheels, inspect the rotors, etc. I noticed that I have been flinging lube from the front diff. Not alot, but some.When I twist the imput shaft, it has about 3/16 slop before it starts turning the pinion. I drove the truck again, and the vibration is still there. Makes sense as everything up there is still turning. I guess that since I can still feel it in the steering wheel, all this really did was clear the transfer case on back.
I plan on removing the nut and pulling the flanged shaft, but without a shop manual, thought it might be wise to ask more knowlegeable folks what I might be getting into and what I can possible acomplish by doing so. Am I gonna dump fluid when I pull it? I traced a hose from the diff. up to the area of the master brake cyl. It looked like a plug in the end of the hose, but when it twisted it, it freed up, and I am thinking it is a breather tube. Is it possible that it was not allowing the diff. to vent, and that is why it is spraying some? When I had the pumkins serviced at 30K, they put the appropriate Redline product in. Truck now has 69K on it. My guess is that there has not been more than part of a pint thrown out (never dripped), so I really doubt it is dry. Ideas on checking the existing level? Any help is greatly appreciated! Also, where do I go for a shop manual....maybe Geno's? The book alot better than the disc? Thanks for any help!

 

I would be willing to bet the pinion nut is a little loose...happened to me- they did not tighten it all the way and your sympotoms mimic what I had.

 

x2 on the pinion nut. Same with me.

 

Thanks guys. Now.........can I ask that you expand a bit on what I am facing here? Even though I still have some warranty left, my dealership leaves me feeling that I would be better off handling this myself if possible. What is involved, and has there been damage done? I have mechaniced for decades and don't mind "gettin after it". Sure is nice to hang with others who have been thru it, and don't mind sharing knowlege!