bad vibrations

[maritimer]

hey folks well now all of a sudden i am getting bad vibrations every time i accelerate or maintain a speed higher then 55-60 MPH grrrrrrrrrrrrrrrrr
any ideas

 

[scooter01922]

Hmmmm, everytime you accelerate or maintain 55-60. If it's not directly linked to a specific engine rpm i would be suspicious of perhaps a u joint starting to go. Give em a wiggle only takes a sec. Could be wrong, has been known to happen

 

[CCATLETT1984]

i'd agree with a ujoint, or one tire could have thrown a weight.

does the vibration change with the position of the steering wheel?
do you feel it in the wheel? or from the seat/body?

 

[underdog]

Had a commercial truck do that to once?
Turned it in to mechanic, For a vibration very simular to the one you have.
Got back for next trip; I asked him if he had it fixed.
He says he greased the release bearing. What ever.
Turned out the transmission input shaft must have been twisted.
Made it about 400Mi and the Input shaft sheared leaving me on the side of a narrow road at night. Wonderful.
Anyway Thats what i know about that.

 

[maritimer]

i'd agree with a ujoint, or one tire could have thrown a weight.

does the vibration change with the position of the steering wheel?
do you feel it in the wheel? or from the seat/body?

the whole truck vibrates bad enough to loosen the hold down nut of the spare tire. it stops when i take my foot off the fuel pedal.i'll check the u-joints in the AM when its dry and light out.

 

[CCATLETT1984]

if it stops when you coast, then yeah its very likely that its driveshaft related. either bad joints or a loose cap.

 

[scooter01922]

Thats quite the vibe, be sure to check on that before something lets loose on ya. On the upside you can really save some time and make a lovely banana milkshake during the A.M. commute. Just plop in a cupholder and GO

 

[AJMBLAZER]

Get the vibe going good and then pop it in neutral. If the vibe goes away pronto then yep, it's the u-joint.

My DD Tracker had either a weight come off the rear driveshaft and then kill the rear u-joint or vice versa. That was damn annoying. It being my DD and Big Ugly being on jackstands awaiting tires it was sorta like driving one of those massaging chairs to work every day for a whole week while I waited for a new driveshaft to show up.

 

[maritimer]

yeah i guess i will have to crawl up under her and take a look at the drive line as it seems that it does go away when coasting and or in neautral. on a good note my lady friend sure likes it LOL

 

[86M10086.2L]

Take a look at the pinion on the rear axle too. I also had a noticeable but less severe vibration show up on my truck. I had noticed a humming sound for a few days before, did some checking and found some dry and worn out u-joints. I installed a new set and everything was great until I tried to do 50-55 mph. Got an anoying vibration. went and checked out the u-joints to se if the loosened or failed and discovered my pinion shaft had about .005-.006 play in it. When I took it all apart it apears that Pvt. Pile or GM installed the pinion with either the wrong shim in between the two pinion bearings or didn't crush it properly. Set everything back up as per the TM's and all seems to be well. Just something else for you to check. I was also greeted by some soft serve ice cream like gear oil in the rear diff but thats another story...

 

[maritimer]

well just an update, 95% of the vib's disapeared with replacment of the rear u-joints. only had t oissuses while replacing them.
1) the book listed the wrong ujoint on the pinion side of the drive shaft *Napa had 3011 joint listed when it was a 3130 joint*
2)the jiont on the pinion side wore through the caps and the pinion yoke some what.

now to tackle the wore out front axle joints