got a wierd vibration that shows up from time to time. sometimes I can hit 80+ no problem... then other times, 68 is a shaker. tires are still looking good. had the front end inspected and they found the drag link & passenger side TRE has play in it. I'm guessing that may be contriubuting to it but thought I'd toss it out there to see what you guys think. no vibrations in the steering wheel, doesnt feel like a tires bouncing...

One other thing to mention... it almost always does it going up hill...

 

If the tires are okay, I'd check the disc brakes, drive shafts and u-joints next.

Any of those could be giving you a bad vibe. The vibe I had way back was the torque converter. But mine was RPM related, 1400 - 1750.

 

I'm thinking axle u-joint... it is definately wheel/axle related. how could I check them to see if they are going bad?

 

My vote is U-joints. I never had any luck feeling play in them by hand. Whenever I felt vibration in my butt at over 50 mph or when I was hard in the throttle at higher speeds I knew it was time to change them.

 

the best way to test the u-joints is to grab them and try and get any play out of them. . .but being you have an automatic you would hear a definate metallic pop when you droped it into gear if it was the u-joints.


something tells me it may be something else.


since you say it is when your going up hill. . .what about when accelerating??? possably transfer case???

 

Well, if it's a ujoint, you can do what I did.... start down a steep one lane grade at about 25-30 mph and meet a bigger truck.... slam it straight into reverse and stand on it. Rear ujoint popped like it was plastic.

I had suspicion of it going out prior, but that little maneuver loosened it up to the point where I'm surprised it didn't just fall out on the road.

 

The front axle u-joints are pretty easy, if it's major play. Just put it in 4wd, jack one tire off the ground and try turning the tire while looking at the joints. If there is movement in the joint itself, then it's shot. Minor play is a little harder to find and you have to remove the joints.

For the d-shaft u-joints, basically do the same thing. You can jack one back tire off the ground and do the same process, but there are so many other points to create slop it makes it a little harder. What you can do, while its a bit unsafer, is go under the truck (with the parking brake on and holding down the service brake) and have somebody else go from D to R a few times. Look for any excessive play on either joint.

Not a perfect way, but it doesn't require removing the joints. Otherwise, the only way to tell in remove them and measure them against the factory specs or dissassemble and look for damage.

 

I had a vibration a while back between about 70 - 75 mph. I also got a squeal so I ended up changing all 3 u-joints on the front shaft. That stopped the squeak and vibration.

 

I had a vibration similar to what you are describing about a month ago. On mine it was mostly between 65 & 75 MPH on level ground but would do it anywhere from 45 to 80 on a hill or if accelerating a little hard. After checking everything on the front end for wear I found one of the u-joints on the front drive shaft was shot. End result was a complete new drive shaft and a smooth riding truck.

I think the drive shaft was out of balance from day one as I always had the vibration between 65 & 75, the vibration under extra load started a few days before I found the bad u-joint. BTW my truck is a 2005, 2500 CTD with 115,000 Km (75,000 miles).

Wayne

 

+1 Replaced the front D-shaft a few times same diagnosis.