OK guys, I'm stumped. My truck has developed a vibration when it's cold. It feels like a driveshaft vibrating but the vibration completely disappears after driving for about 15 miles or so. I can't feel it in the steering wheel, just in the floor. I removed the front driveshaft and checked all the joints for play and they are all tight. Drove it without the front driveshaft and vibration is still there. I checked all the u-joints on the rear driveshaft and all seem tight. What the heck is going on?

 

Maybe a front hub bearing? Could be lubricating itself once it get hot?

 

Could be. Wouldn't that indicate that my front differential is low on oil? That's one thing I haven't checked.

 

Should be a self sealed hub. Try removing the abs sensor that leads into the hubs and squirt a few drops of grease in the hole. Alot of guys are doing this due to the sealed hub wearing our to early

 

Right, didn't think before I posted that one.

 

This may sound like a long shot, but I just thought of it yesterday while I was bumping my fronts tires to 70 psi...

As I took off the air chuck, it blasted some water on the rim..... I had moisture in the air tank that I was pumping in the tire.

Now if you had a few ounces of water in the tire it would freeze on the bottom of the tire and cause a shake when you started out. After the tire heated up and the ice flexed, it would redistribute and the shake would go away.

What do you guys think?

 

randall,

Maybe your tires are "flat spotting" in the colder weather. Then warming as you drive.

You could prove it by jacking the truck up when you get home with warm tires and lowering it again right before you leave in the morning.

 

Right!

 

That's not a long shot, I've seen that before (years ago when I worked in a shop). Most places use good dry air but given the right situations it can happen.

 

The frequency seems too high for it to be a tire out of balance. Also, every time I get out of the truck after driving I smell gear oil but I can't find evidence of a leak anywhere, front or rear. I'm starting to get a little worried.

 

I have a 2004 and I always smell gear oil too but can't for the life of me figure out where it's coming from. It's driving me nuts.

 

Another long shot not sure if it would make much of a shake, but i had a similar shake in my truck and then i replaced my front end with new ball-joints, shocks, and all the tie rod ends plus my u joints.. when i replaced my u joints the joint would move freely in one direction but was really really stiff in the other direction, there was no slop in the joint at all. just a thought! not sure if that would cause a vibration.. good luck!

 

Yeah, I talked to my dad and he has me convinced that it's probably one or more u-joints in the rear driveshaft. I'll have to pull it off and check them. As for the gear oil smell, he said to check on the inside of the rear brake rotors for oil. I haven't checked there yet but it makes sense because if it's an axle seal leaking it would drip onto the brake rotors and I wouldn't be able to see it because it would fling the oil onto the inside of the wheels.

 

gear oil if it is coming out will be all over the place like on the fenders and on the springs and such also what year truck do you have fill out your signature so we know what you got it is in the user cp portion of the page. lube your front hub bearings and spray some pb blaster on the u joints mine were a pita to get out!

 

My signature is filled out. It only showed up in my first post in this thread for some reason.