Hi All,

  I have another weird car symptom that i'm struggling to figure out and wanted to get some ideas.  Over the past couple of months i've had an intermittent rhythmic wobbling feeling.  At first it would only happen after about 45 minutes of driving at highway speed.  First time i was worried that i had failed to tighten the lug nuts or strut mount bolts.  Pulled over, found that everything was tight, and finished the drive.  I was thinking maybe a rim spit off a balancing weight that i didn't notice.  It had almost a bouncing feel similar to an out of balance wheel.  Only difference was that it seemed to be related to throttle.  More throttle, more wobble.  Let it coast, and the wobble is gone.  Sometimes i think that it feels like it's coming from a specific corner but not always.  Checked things over that evening without finding anything loose in the suspension or alignment hardware and did a test drive the next morning to find that the wobble was gone.

  Since then it has happened off and on.  Pretty much only after 45 minutes or so at highway speed.  I can drive 65 to the town 20 minutes down the road and it won't happen, but if i try to drive an hour it does.  I also have a part time job at a ski area and have a 45 minute drive there.  It happens on the uphill leg but not the downhill leg.  In the past week it's now started to happen even on slower drives around town and definitely seems throttle related.  Engine is stock EA-81 except for a weber swap.  It has the usual problem of going through CV axles every year or so and i recently changed the right front, but the early episodes were before swapping it.  I actually thought that the bad DOJ was the problem until it started happening again.  I'm running 14" rims with otherwise standard snow tires right now, so it is 1" oversized, but i've used these same rims the past two years without problem.  Haven't had an alignment done in a while, but with the intermittent nature it doesn't really seem like that'd be the problem? 

  Any ideas?  I'm stumped by the way that it comes and goes.

Does the steering wheel wiggle varying with rolling speed?

Like DaveT said if the steering wheel turns on its own when accelerating it will be an outer axel joint. If the steering wheel turns right, it is the right axel, if it turns left, it is the left axel. I had a brand new (after market) axel do that because the outer joint was way too tight. I moved the axel to the other side and the steering wheel turned the other way. It went on my scrap pile and I installed a reman axel.

If the steering wheel does not turn, then it will be an inner joint on one of the axels. When accelerating the inner axel joint is pushing outwards against the wheel. The suspension is mounted with rubber bushings so it will give a little, thus producing a wobble feeling.

 

2 hours ago, HRBrat said:

More throttle, more wobble.  Let it coast, and the wobble is gone.

A bad inner joint can cause that. When you lifted the car off the wheels they hung down so the joints moved to a different position that was not worn as bad. After driving for a while the joint shifted back into the worn spot and makes the wobble. That always happens to ours when the boot cracks on the inner joint and it gets dirt in it.

I meant wiggling - left right constantly,  or fading in and out.  I've had 2 causes of this.  1 is out of balance tire / slightly bent rim.  Other was tread bubbled off the steel belts in the tire.  This turned out to be caused by the alignment being too far off spec.  Jack up a wheel, slowly turn it while watching the tread surface.  Obviously,  it should be steady, not changing.

Thanks for the input!  I just went for a drive today to check.  It accelerates without pulling in either direction.  At 40ish mph i can sometimes feel a vibration or low rumble through the steering wheel, but it isn't really doing the wiggle back and forth.  At highway speeds it does do a small side to side wiggle that does vary with the speed of travel.  At lower speeds i can kinda feel it through the shifter. 

I'm guessing it's not the wheel as the problem started during the fall when i was still running my 13" rims with all seasons and when i swapped over to the 14" rims with snow tires it didn't really make any difference.

The right axle is almost brand new with less than a thousand miles on it.  Felt good out of the box.  Left axle was put on over the summer and probably has four or five thousand miles on it.  They both feel smooth when i rotate the wheels off the ground and both feel solid when i pull on them from below.  Of course they are both crappy after market axles that have been failing frequently.  Anyone know how to get one that sucks somewhat less?

Search high and low for old used OEM ones.  clean re grease and re boot.

A long time ago, I remember seeing people post about one aftermarket brand that was almost as good, but they stopped making them.

Edited January 31, 20206 yr by DaveT

I have had a three week old complete new shaft develop this quite powerful wobble. I usually keep a known good shaft I made up out of old bits, purely as a diagnostic swap in

One of the longest lasting pair of shafts I had were slapped together out of a wide assortment of used bits

Uni joint on the tail shaft. Check them for play. 

Also inspect you engine/gearbox mounts. 

Cheers 

Bennie