driveline vibration - diagnosis (1 Viewer)

[euclid]

Driveline vibration showed up a few weeks ago, keeps getting worse.

Happens at all speeds, can't drive through it. More noticable at lower speeds. The worse is breaking, down around 5 MPH.

Front driveshaft passes all checks, re-torqued everything and it's fine.

Brakes are new all around. Rears are 6 months old.

Jacked up the back and put it in drive on the stands. Vibrates noticably in drive and reverse.

Ballanced tres last week, they are fine.

Any ideas?

 

[cruiser88]

when is the last time you changed your rear u joints give them a check.put it in neutral and check the u joints and pinion joint for slack by moving them around. and while your under ther you might as well go ahead and grease it all.let us know what you find out

 

[Dynosoar]

Make sure the drive shafts are "in phase" this means the u-joints front and rear (on same driveshaft) are lined up in the exact same direction.

Dynosoar

 

[cruiser88]

it also helps to have somebody to ride in the back that knows what they are talking about.switch from side to side looking for wheelbearing noise or for 3rd member noise.

 

[euclid]

Driveshaft rebuilt about two years ago. I had the dickens gettin it right, but they finely got it. Don't think that's it, but I'm thinkin I'm gonna let the drivetrain shop take a look at it.

 

[Clutchee]

Has this happened since the rear axle swap?
Curious if that would have maybe been in the "jes" axle.

 

[euclid]

Has this happened since the rear axle swap?
Curious if that would have maybe been in the "jes" axle.

Yep, but there were no problems in the first couple of months. The pinion is leaking a tiny bit, but I don't feel any play.

Jackson Powertrain gets it this AM.

 

[srplus]

something to check quickly

i had a similar stumper on a previous vehicle... could not figure out what the heck was wrong that kept the thing shaking - especially rougher going slow. went thru all kinds of gyrations trying to figure it out including replacing all of the u bolts. found out answer when i went to have the tires balanced and aligned (which had been done not that long before problem showed up).

turned out that the tread on one of the tires has separated and there was a smallish bubble on that tire only. bubble also got larger as tires warmed up... they were expensive tires & not a third worn... (no road hazard back then but i talked manufactures rep into replacing all four).

from what you've said the tires are fine since you had it jacked up and it danced on the stands.. but it would be a pisser if that was it. might help someone else... like has been repeated many times around here: eliminate the simple things first.

 

[euclid]

Ends up it was a frozen u-joint. Shop said they have never seen one act like that. It's only a year old. 3 sides of it were lubed perfectly, one side was "dry as a powder house" to use their words. No pinion damage.