control trac 4wd w/bad vibs

[Mr. Pheasant]

Got bad vibs! Vehicle vibrates real bad 60/70 mph. Jacked up rear axle, rear Dr/shaft appears to turn true. Noticed frt Dr/shaft turning (under power) wheels not turning (they're on the ground). Pulled frt Dr/shaft. Vibration still there but not as bad......My Question is....Is the frt Dr/shaft suppose to be turning under power while slector is in 2wd? I thought Electric clutch in transfer case locks up only in 4wd position? Help!

Mr. Pheasant

 

[chance942]

Yes if you do in fact have CON TRAC. What does your selector in the cab say? For CON TRAC it should be AUTO,4HI,4LOW

 

[dynamite196]

yes a small amount of power always goes to the front wheels (something like 4% if I remember correctly). Are you sure the problem is in the driveline? You could potentially have a problem with an out of round tire or tires where they'll still balance out in the shop but shake like crazy on the vehicle.

 

[Mr. Pheasant]

Rear of veh. shows... Control Trac 4wd, Selector has 3 positions 2wd, 4wd auto, 4wd low. Vibration is heard as well as felt. I'm checking Dr/shafts first. Removing frt shaft help lessen vibration. I'm just wondering is this frt shaft suppose to be turning all the time!? If so...seems like a waste of energy!

 

[Mr. Pheasant]

Oh, by the way. Good Morning!