I have a 2000 X V10 Limited with 153K miles and I'm not quite sure of the service history. When I test drove it, I didn't get it over 55mph.....I went home, flew to the bank, got the money, came back a few days later and bought it. I test drove it and had to have it.

On my way home with it, I noticed a vibration around 65 - 70mph that came and went...it wasn't constant. I thought maybe it sat for a while and there was a flat spot in my tires. It wasn't a rapid vibration, it was more like I had an out of balanced tire. On my 90 mile trip home, it seemed to go away and I haven't noticed it again. I've take a 2200 mile trip with it and 750 mile trip already with no highway issues.

Since i picked it up last month it hasn't happened much, but I noticed last night that I was getting that slight ungulation/vibration around the same speed again. Could it be my drive shaft out of balance? I went under my truck the other day and notice oil on my rear pumpkin. It leaked onto the drive shaft and has spun all over the under belly of my truck. It's not soaking, but it looks fresh and it's obviously from the pumpkin. Could this vibration be an issue with my rear end? what should I look for or do next?

Remy.

 

Yep ... pinion bearing & seal ... may as well do U-joints, too while you (or they) are under there.

 

There's no clunking or jumping...the truck shifts smooth and doesn't slam when I go from forward to Reverse like my Tahoe use to do. I had to replace the U joints in that thing every 50K miles, so I wasn't sure if it was the Ujoints or not.

Univeral Joint Services is close to my house, so I can bring them the drive shaft. Is replacing the pinion bearing and seal a big deal? Should I have someone do it, or can someone with basic mechanical knowledge (like me) do it?

if I do it, should I, or do i have to drain the pumpkin and replace the fluid? My father in law is an ex-auto mechanic, I guess if I'm desperate, I can ask him to help.