VIBRATION!!! ARGGGGHHH!! HELP!!!

[truck7575]

I have 2003 Excursion and I have a vibration that shakes the steering wheel very strongly and is very loud between 50 and 65 mph. I had to replace the ball joints so I have replaced a lot of stuff on the way in and out. I have upgraded to dual fox 2.0 steering stabilizer setup, rebuilt the axles with new seals and ujoints, new ball joints, new hub bearing assemblies, new warn premium hub assemblies. I have new rims and tires and have had an alignment done, i have removed the front driveshaft to rule it out as a cause for the vibration. What ideas do you all have as to where to look next? a couple of ideas floating around in my head are the rear drive shaft being out of balance, a bad rear drive shaft u-joint, rear pinion yolk bearing being bad, and someone mentioned a cracked flywheel? Would it hurt the vehicle to take off rear driveshaft and put on front and put it in four wheel high and drive up to that speed and see if the vibration goes away? Any help would be great guys... thanks!

[texaspsdx]

Have you checked the rear pinion angle?

[mtnsammy]

With your tire size and the speed range I would check balance again. Most common at 60-70mph but it is a cheap fix.

[ColLonewolf]

Originally Posted by truck7575

I have 2003 Excursion and I have a vibration that shakes the steering wheel very strongly and is very loud between 50 and 65 mph.

Sounds to me like the notorious "DEATH WOBBLE". Check your track bar bushings.

[Xx_Razgriz_xX]

I was thinking the same thing. Death Wobble possibly. Very common on these.

[truck7575]

Brand new adjustable trackbar and bushings got installed with the new suspension.. Bolt had to be torqued to almost 400ft/lb.... Today I reinstalled the front driveshaft and locked the front hubs removed the rear driveshaft and put it in 4wheel drive, vibration is gone, I am going to drop my drive shaft off and get it checked at the local diesel driveline shop. It's just so weird that the vibration in the steering wheel was able to travel up through the tcase, trans and engine through the steeringwheel! I guess ill see what the driveshaft people say, the rear pinion felt good when i jerked around on it.

[truck7575]

PROBLEM FIXED! Rear Drive Shaft Had a bad U-joint and was o!!!!ut of balance. AHHHHHH!!! Smooth Sailing!!!

[ColLonewolf]

Odd that a rear drive shaft would wobble the steering wheel. Congrats on finding the issue.

[truck7575]

That's why I had such a hard time figuring out where the vibration was coming from... Ultimately... Running the vehicle in 4wd with no rear drive shaft helped me to isolate the issue to the rear shaft or axle and fortunately it was the driveshaft... Funny thing is that the guy I bought it from had just replace the rear shaft unjoints last year but did not get the shaft balanced... This must have caused premature failure of the new ujoints... And the fact that I knew he had replaced them already even lea me further in the wrong direction... But it's riding good now so I am relieved!