Diagnosing Driveline vibration/noise

[matt-jenkins]

Lately Ive noticed a vibration on take off that has turned into a tinging at low RPMs and sometimes a screetch at higher RPMs when the truck is loaded I.e. going up a hill or even just when i use heavy throttle.

the U joints feel tight and the center support bearing has some play but it doesnt seem overly loose. from day one I suspected that bearing, anything else I should be checking or any helpful tricks to track down the location of the noise?

Thanks guys!

 

[Black dawg]

A trick that I use regularly to find dry caps on a u joint, is to drive the truck and then feel the ends of the caps. Any that are dry and binding will be much warmer than the rest.

 

[Blind Driver2]

Have you greased the u-joints?

 

[matt-jenkins]

My U joints are the non greasable varity,


Would bad U-Joints make the squeeling sound as Im driving? i assumed this was the support bearing because I didnt think bad U joints would make much noise once the truck was rolling.

 

[Blind Driver2]

I never liked sealed joint of any type. I'll bet your are all dried out.

 

[RLDSL]

Second that on the dry joints. Nt much you can do about it . If you have a decent temp probe you can check the caps on teh joints for hot spots and see if any are worse than the others right after a drive but the heat will quickly spread through the spider on such a small joint. The support bearing can be greased. You can get a grease needle at most good parts stores to fit a grease gun ( a thread on one, not one that pops into a zirk cap) or go to a farm supply and get a heavy duty reusable vetrinary syringe and the largest needle they have and fill it with grease and work the needle in around the edge of teh bearing seal and push it in a bit and shove some grease in there. repeat this in a few spots around the seal ( for that matter, you could try it on the ujoint seals if they are likely toast anyway) Usually the support bearings will go another 100k miles or so if you catch them before they get too noisy ( actually they will last as long as you can keep pumping greas in there but the seal will eventually decide that it wont want to stay in place, but it's a great way to make a disposable item last