Vibration over 45 mph

[terryt]

I have a vibration over 45 mph

I have replaced tires  i have had the wheels balanced twice replaced sway bar links shocks all the brakes

ball joints appear to be good and tight Tie rods are tight 

1990 Comanche 4.0 2wd no modifications at all. Some people tell me to replace the steering stabilizer then when i look on line it says that would not cause a vibration.

looking for recommendations please

[Pete M]

where do you feel the vibration?  in the steering wheel?  your feet?  your seat?

[AZJeff]

Steering stabilizers DO NOT remove vibrations.  They merely reduce them.

 

Pete M raises some good questions about/where the vibrations are felt.

 

Based on the speed you stated, it sure sounds like a tire balance issue, but answering Pete’s questions will give some clues as to the source.

[JYau]

Did you check the trackbar? Also, the stock control arms are pretty flimsy too, not to mention that the bushings could very well be worn and squishy. 

[derf]

I agree that a detailed description of the vibration would help.

 

Sunce you have had the tires balanced, that's likely not the issue.

 

Things to check:

 

1.  Ball joints.  Get the tires off the ground and really move the tires around.  Use a pry bar if you need to.

2.  Steering components, specifically tierod ends.  At the steering box, at the joint where the two sides meet, and out at the knuckles.  Check that the nuts are tight and there is no excessive play in the joints.

3.  Bushings.  All 4 control arms and the track bar.  Check bolts are torqued to spec and that bushings aren't worn.

4.  Steering stabilizer.  It doesn't hurt to have a fresh one if it's worn, but it won't cause or solve vibration by itself

[terryt]

i have had it balanced 2 times and even the rear view mirror shakes a little

i definitely feel it in the steering wheel again new tires ball joints seem tight

Alignment shop says tie rods are good

[terryt]

i will double check the suspension again i have to be missing something

will keep this thread posted

Thank you everyone!

[Chad R]

Just for kicks move the tires front to back to see if the shake moves 

[GonzoTheGreat]

Check the track bar. Any play in the joint, the bushing, or the axle-side mounting hole will cause shimmies and wobbles. Remove an end and give it a thorough inspection. You won’t always see play in the ends if it’s still in the vehicle and under load. 

[AZJeff]

One of the best ways to check for steering system looseness is to have a helper sit in the vehicle with the engine off and rock the unlocked steering wheel side to side until they feel the force to turn the wheel get high.  This essentially takes all the lash out of the steering system.

 

while the guy in the cab is doing that activity, you climb underneath and check each joint one at a time.  The way you check the joint is both visual and by feel.

 

the “by feel” part involves grasping the individual joint by hand, trying to encircle both halves of that steering linkage connection with your hand and fingers. You are attempting to feel for any relative play between the two parts of that particular steering linkage connection.

 

this test only works on the steering linkage and on the track bar connections.  The test for control arm looseness is only really feasible with a BRIGHT flashlight and visual inspection, looking for cracks in the rubber and/or permanent rubber deformation.