I've been reading the forum for weeks trying to fix it all, and finally decided to join.

I've got steering wheel shake between 30-45, and then seat shake at 60+. It smooths out some about 75 and higher, and it occasionally gets bad seat shake at around 35. Shake doesn't really change whether accelerating, coasting, or braking.


I've got 37" tires and 4" lift. Yes, they are 37's on only 4", did some work with an angle grinder but no frame or spring rub. This is my 4th lifted truck and I've never had shake like this before. Here's the specs on the truck and what I am planning to pursue based on others threads I've read. I'm not a mech, but I've been around cars enough to be pretty damn confident with my abilities.

2000 XLT V10 Gasser 4x4
217,xxx miles
Only service records on truck show oil changes and spark plugs, no idea on what else has been done before I bought it a year ago.
Wheels and tires balanced and aligned within the last month.
2" add a leaf and 2" shackles front
2.5" add a leaf and 1.5" blocks rear
I've got the one piece single cardan rear driveshaft with slip yoke at t-case end and flange mount to t-case and rear diff (so no carrier bearing)

Here's my thoughts:
Steering Stabilizer: Running Factory Still (cause of steering wheel shake?)
Driveshaft: No weights welded on driveshaft, is it out of balance?
Rear Diff: Haven't measured angles on U-joint to diff, but it doesn't look that changed to me.

It does have add a leaf but I had (ex has it now) a 00 Durango with 9" of lift that had no shake, just really stiff springs. The angle on the rear diff u joint in that was also more extreme than the one on the X. The X shook some before the lift but not like it does now.

Any wise words?

 

double check the wheel/tire blance. all my vibrations i've ever had has been related to a bad balancing or loosing weights.

 

You should try the road force balance that the ford dealerships offer. The tires are balanced under pressure, simulating road pressure.

 

Had my tires balanced and alignment done due to similar issues, and it didn't fix the issue. Took the tires to another shop that corrected the poor balance that the prior had done and it cleared up.

 

What was your vibration like? Mine seems really bad, like more than just poor tire balance