Violent Shake

[smudvapor]

I have a 2000 Ranger 4x4 3.0 automatic. At around 55-60 mph, it violently shakes. I am not talking about vibration, I am talking about a shake that is so violent that you will lose control and crash the truck. I have never experienced something like this before. I have had it on the lift and nothing is loose. I checked the U-joints and all is good. ( I replaced one.) The wheels spin fine and nothing seems loose wheel bearing-wise. Has anyone got any ideas?

 

[rusty ol ranger]

Tire weight knocked off?

Bent rim?

 

[smudvapor]

Both have been checked. All good.

 

[dvdswan]

Do you feel it in the seat of your pants or in the steering wheel?

 

[James Morse]

Warped rotor?

 

[ekrampitzjr]

Is it only at 55–60 mph, or is it at any speed from there on? In other words, is it still there at 65, 70, etc.?

Can you tell if it's coming from the front or rear?

How are the ball joints and tie rod ends? Anything such as a tie rod bent in the front from an impact with something on the road?

Any mud or anything else (plastic trash, etc.) stuck/caught on a front shaft?

Anything amiss with the engine accessories or pulleys?

Any chance of one or more cylinders not firing? Any codes?

 

[pjtoledo]

remove front drive shaft then test drive. the cv on it can cause your symptoms, but usually start to shake at lower speeds.
warped front rotors do the same. stuck calipers can cause the warping. slightly ride the brakes during vibration, does pedal or steering wheel change?
tire deforming due to separated bands? that may only show at speed.

 

[James Morse]

Different year, but shop manual says ('97)
"Typical high speed vibrations (above 45mph)

Axle and companion flange runout or imbalance
Driveshaft imbalance
Excessive tire-wheel and drum assembly imbalance
Tire roughness due to high non-umiformity or out-of-balance condition
Rear axle pinion gear pitch line runout
Excessive tire and wheel runout
Worn suspension components
Exhaust vibration"

"know the difference between improbable and impossible" (you might think it impossible, but it's just improbable, they say)
"just because parts are new doesn't mean they are good"
"don't cure the symptom and leave the cause"
"be positive the cause is found"

those are all quotes from the manual. it'd be worth it for you to get the shop manuals because they tell you how to find whatever kind of noise or vibration you have going on there

 

[Josh B]

raise the frame and let the steering sag

 

[James Morse]

If you can shift to neutral when it's happening and see if it changes or not that would eliminate / imply some things
like if for some reason your driveshaft was out of balance it would go away in neutral (at speed)
if it doesn't change then you know it's not that
I'm just looking in the book... guys here will know more

 

[smudvapor]

Thanks for the input guys. I found the problem...And it's BAD.

Time to find another Ranger.

 

[James Morse]

It looks like frame or frame member is rusted apart. Would have to rebuild that section? But if it's that bad this might not be the only place it's about to let go. Sorry to see that.
They didn't have that on the list.... "Frame is rusted apart" I guess they figure you'd see that. Maybe it falls under "improbable, but not impossible".

 

[pjtoledo]

wow, good thing the torsion bar is still there as it's all that's holding the lower arm in place.

 

[smudvapor]

It looks like frame or frame member is rusted apart. Would have to rebuild that section? But if it's that bad this might not be the only place it's about to let go. Sorry to see that.
They didn't have that on the list.... "Frame is rusted apart" I guess they figure you'd see that. Maybe it falls under "improbable, but not impossible".

Yeah, the rot goes way up and across. That lower mount is completely separated from the frame. It's a goner. It's a shame because everything works. That's how it goes I guess, I'm just glad my wife wasn't hurt driving it.

 

[ekrampitzjr]

OMG, sorry for that discovery. At least no one was hurt. Might be a good idea to check the frame under the bed because usually the rust is worst there. If it's bad enough, you should get it hauled away instead of even driving it to the salvage yard.