Vibration Source

[Ic_65]

I have a vibration that i can't find the source. I replaced the tires, had them balanced 3 times. Then replaced the tires with a new set but the vibration is still there. A buddy said it might be universal joints but there is none if the typical clicking and no movement i can see, but the center carrier baring had some movement. Could this be the source and how much movement should it have?

Thanks

 

[CAVEMANN]

There doesn't have to be any play or "clicking in them, I have seen them freeze up to the point that they can't move. The resulting binding can cause vibrations, possible too that the driveshaft may have tossed a weight. The carrier bearing could be frozen up too forcing it to rotate in its rubber dampener mount, I would suggest dropping the drive shaft & checking each u-joint individually & check the carrier bearing. How many miles are on the truck & what are its operating conditions. I haven't had to change a u-joint in many, many years.

 

[Ic_65]

There doesn't have to be any play or "clicking in them, I have seen them freeze up to the point that they can't move. The resulting binding can cause vibrations, possible too that the driveshaft may have tossed a weight. The carrier bearing could be frozen up too forcing it to rotate in its rubber dampener mount, I would suggest dropping the drive shaft & checking each u-joint individually & check the carrier bearing. How many miles are on the truck & what are its operating conditions. I haven't had to change a u-joint in many, many years.

Thanks for the reply caveman.

It's a 2016, 4 x 2 Laramie with 65000 miles on it daily driver only on the highway. Have done some minor Towing but nothing even close to the weight capacity of the vehicle.

I know how to I know how to check the U-joint but how do you check the carrier bearing for excessive wear? I've been under the truck and there is nothing obviously wrong with it. I've grabbed the driveshaft and the U-joints don't move but the center carrier bearing has a certain amount of movement but nothing excessive that I am aware of. How much play should it have?

 

[CAVEMANN]

Ideally you should pull the driveshaft, and other and make sure the bearing itself isn't seized, it should be slightly snug in the rubber, BUT there are several types of cushion s for the bearing, some are like an air filled "pillow", while others may be more like soft live rubber, and others may have a solid inner and outer part with the middle part consisting of interlinking triangulated fingers holding it all together. 65k is nothing for a modern u-joint under normal conditions unless it is used in salt & snow or a really wet location or frequent boat launching. I managed the maintenance on a fleet of ambulances for about fourteen years and normally would easily get well over 300k on u-joints, often outlasting a transmission. Another thought would be excessive angle from a lifted vehicle etc, how about engine & transmission mounts etc.? Just a few different thoughts, best of luck, these kinds of problems can be a bear to locate sometimes. You also mentioned about having the wheels balanced 3 times, I would hope in todays world they are doing a spin balance set up with proper backspacing etc.

 

[Ronald Doupe]

Have you had a Road Force wheel tire balance done, I have a good feeling that will correct the problem

 

[Ic_65]

Have you had a Road Force wheel tire balance done, I have a good feeling that will correct the problem

Thanks for your input and that was something i hadn't know about before. Yes they (said they) did one and said they barely found any difference. Afterwards, the vibration was still there.

It's not as bad all the time and I can't feel it in the steering wheel which makes me think of the u-joint or center bearing. The shocks appear to be good using the "bounce" test.

 

[carlhenry]

pull the drive shaft and check the joints 4 binding

 

[CAVEMANN]

I had a customer that had a very, very low speed vibration on his 79 Chevy 1/2 ton, we went through everything, balanced several times, checke alignment, he had alignment check on a top of the line computerized machine, they him all they could do was screw it up, he told them that it was done with old school gauges and a trammel bar, I did the alignment & they told him "that guy really knew what he was doing", Wheel alignment was my specialty & had an EXCELLENT reputation here locally. It turns out that it was something to do with the tires. Ceck everything that rotates in connection, driveshaft may have slung a weight, or may have some hidden damage, a very small dent could cause it.