Intermittent Shaking

[RobWinn]

I have had a strange mind boggling problem with my Eagle a couple of times since I got it a month or so ago.  It's hard to describe but it basically feels like one of the wheels (passenger front?) isn't round any more and the whole front end (whole car really) shakes but, I think something is sticking and releasing.  It happened once when I first had the car before I sorted out the carb issues then nothing for 500 miles or so.  Yesterday when I was going about 20 getting ready to turn it did it again.  I let off the gas and then gave it again and it stopped.  Then all was fine for about 10 miles of driving around town.  I stopped at the gas station and then pulled on the highway and once I was nearly at speed (55ish) it started shaking so I pulled over.  I went in reverse a bit (it didn't seem to shake or wobble in reverse btw) then went forward and it was still doing it.  Got out of the car and looked at the front end checked all the major bits for tightness got back in still wobbles.  I had driven the car in 4 wheel drive in the morning to make sure it was working ok in the morning so I figured it may have been something to do with that.  So I put it 4WD backed up went forward and it seemed to be a little better but it still wobbled.  I remembered then that I had to restart the car when I had the issue the first time so I turned it off and back on, took it out of 4WD before I did that btw, drove forward a bit and it seemed a little better so I just kept going slowly and it seemed to be all better.  I drove it home (15 miles) no more problem.  This morning I drove to work and it would intermittently start to shake.  I would let off the gas and it would stop shaking right away and after doing this 3 times or so, at 45-50 mph it eventually stopped doing it and I drove the remaining 3 or 4 miles in town with out issue.  Any help or thoughts are welcomed Thanks!

[IowaEagle]

Sounds like the infamous death wobble.  I suggest having an experienced front end expert examine the front suspension.  Most of us have had that and almost always it can be traced to worn front end parts.  You may want to first check your front strut bushings.

[Amc1320]

Sure sounds like strut rod bushings, or the hole the strut rod goes thru is warbled out, I had this problem as well

Luckily I just replaced the bushings and all was well

Not a hard fix and the parts are reasonable, you will need some large size wrenches and get a front end alignment after the repair

[carnuck]

Strut bushings or idler arm. Although I had wheel bearings do that once.

[AMC of Houston]

And of course the infamous steering dampener (the shock absorber-looking thingie on the steering linkage).

[carnuck]

That could cover up the symptom but not be the cause. I tossed mine.

[IowaEagle]

If the bushing mounts are cupped you will need to weld in some correct diameter heavy duty washers.  Places that repairs big rigs will probably have the washers.

[1985amceagle]

another concern is the strut rod itself. mine has started to rust away on the threaded section that is surrounded by the bushings. this will also be an issue when the car is aligned as that is one of the adjusting points that is required.

[captspillane]

And of course the infamous steering dampener (the shock absorber-looking thingie on the steering linkage).

The steering dampener is meant to help with resonance shaking, which is a common Eagle issue and the only issue I refer to as "death wobble." That issue can be very frustrating because each individual part is okay but worn enough to interact with all the other ones that are also worn.

What you described doesn't sound like a harmonic issue and sounds like a problem needing immediate attention caused by a single part about to fail.

I suggest you schedule it for a new round of the important bushings and joints just because they are old and likely to cause the harmonic shaking eventually. That will knock out a couple possibilities shotgun style by just replacing stuff that should be done anyway, and will also give you or your mechanic a good long look underneath while you do the work. Hopefully you'll fix problems you didn't even know you would have in the process of fixing the biggest one.

[RobWinn]

Just to give you all an update.  It turns out it was a worn CV Shaft.  The outer CV joint was locking in various positions and causing it seem like the wheel was out of round.  All is fixed now.  I do intend to eventually go through the front end but I may wait until it's warmer out. 

[eaglebeek]

Was the rubber boot torn before you took the half shaft out or was the boot torn during removal?

[RobWinn]

It was already torn.  Looked like it had been for years. Probably one of the reasons I ended up with the car for so little dough. Hopefully I'm almost through with all the neglected maintenance.   Power steering pump is next then the alternator and she should be a nice reliable daily driver