Wobble/Vibration Frustration - Help w/ Diagnosing

[awehlage]

Here are the symptoms:

1. Slight wobble in steering wheel/drivers seat when accelerating in a straight path. Only happens somewhere between 15-20 mph. It happens from a dead stop or decelerating below 15 mph and then accelerating again. Think slowing down for a red light and then turns green. Doesn't matter the road surface (smooth, grooved, construction zone, gravel). Doesn't happen when accelerating through a turn either left or right.

2. Vibration in steering wheel/drivers seat when accelerating. Only happens between 55-70 mph. This always happens no matter the road surface. It also happens always when accelerating from a dead stop or decelerating to under 55 mph and then accelerating again. It is worse when going down an incline but not as bad going up an incline.

Here's the recent history of maintenance:

1. Replaced drivers side CV joint (whole assembly). Once in August (cheapest one I could find) and again this past weekend (A1 Cardone brand - not re-manufactured).

2. New drivers side tie rod end in August (Moog brand).

3. Front end alignment in August after tie Rod replaced.

4. New drivers side and passenger side wheel hub bearings in August (SKF brand).

Reason for the above repairs:

I was cut off in a round-about and had to jump the center island curb as to not get smashed. Before this everything was GREAT! None of the above problems. I have torqued down to spec EVERY FRONT (not rear) suspension component that has a bolt just to make sure.

*Side note - I don't think it's a tire/wheel problem as I just swapped my 20" summer wheels for 17" winter wheels. I did have a bent 20" wheel after the collision with the curb but swapped it out with the spare. Same symptoms on both sets of wheels/tires. Coincidence that both sets are my problem...probably not.

Thanks for reading and hope someone has a suggestion I might be overlooking. Please throw out anything that it could be!!

[genedjr]

A couple of thoughts:

• Can I assume you only banged the front and not the whole car over the curb?
  
• Did you check the bushings on the A-Arms?  I have had distorted bushings do kinda what you describe.  Low speed wobble than at some harmonic speed the wobble returns.
  
• I note that you did not say anything about the ball-joints.  With the stress of banging a curb this is another area that may cause issues.
  
• I also note you said front wheel alignment only.  Was the back checked?  Can I assume the car drives straight at all speeds when you let go of the wheel?
• Have you checked the A-arms themselves.  The aluminum does not show stress like steel.  This is fairly easy with a tape measure measuring any differences between each side from the ground to various points on the a-arm.  You can also check positions from the uniframe to the a-arm

Let us know what you find.

...gene

One last thought - have someone drive next to you.  The wobble may be visible.  Check both sides.

[awehlage]

Gene, thanks so much for the response!

The front drivers side wheel is what took the brunt of the force. The subframe was not damaged at all.

When you say A-Arms are you referring to the lower control arms? If so, I visually inspected them but will try and measure like you mentioned.

Also, when you say lower ball joints are you referring to where the knuckle/hub assembly connects to the lower control arm (A-Arm)? It looks like a tie rod end inverted held on by 3 bolts? I thought about this as I was changing my CV axle. It's a cheap part to replace anyways so I will look.

The wobble is not visible from someone driving behind. There is no noise when the wobble is present and can't really tell about the vibration at 55-70mph. All I know is my car was smooth before all this and now drives like a 4 banger on spare tires ?

[genedjr]

Nov 5, 2014 18:02:33 GMT -6 awehlage said:

Gene, thanks so much for the response!

The front drivers side wheel is what took the brunt of the force. The subframe was not damaged at all.

When you say A-Arms are you referring to the lower control arms? If so, I visually inspected them but will try and measure like you mentioned.

Also, when you say lower ball joints are you referring to where the knuckle/hub assembly connects to the lower control arm (A-Arm)? It looks like a tie rod end inverted held on by 3 bolts? I thought about this as I was changing my CV axle. It's a cheap part to replace anyways so I will look.

The wobble is not visible from someone driving behind. There is no noise when the wobble is present and can't really tell about the vibration at 55-70mph. All I know is my car was smooth before all this and now drives like a 4 banger on spare tires ?

On a-arm - yes lower control arm.  It's heavy cast aluminum.  If the Arms do not measure the same from left to right sides, I would further check the bushings (pivot points).

On ball joint - yes - like a tie rod end.  But these are riveted on by the factory, if you see bolts, its been replaced at some point.  Who knows what quality parts were used.  Google testing ball joints.  It's not hard to test but seeing video of good and bad results makes it a snap.  BTW - there are upper and lower ball joints to check.

Let us know how it goes.
...gene

[awehlage]

Thanks for the clarification. I just wanted to make sure we were both referring to the correct parts!!

So I measured the control arms last night and I believe they are still true and not bent in anyway. I compared the measurements from drivers and passengers side to just be sure and they are pretty much the same...I mean within a 1-2mm difference.

I will do a more thorough test on the lower ball joint. I just looked up in my FSM and there is nothing about an upper ball joint and I definitely don't see one on the car. Are you referring to something else?

[sall]

Only lowers.

[genedjr]

Yes, my bad - only lowers.  The pivot point for the top is the strut.
...gene