Originally Posted by wojomoto
I have a shaking issue but its very intermittent. Seems to happen most during towing or shortly after towing. Normally if I stop the car and restart driving (I don't turn the engine off) it goes away. It kind of seems like something starts it shaking and it just cant stop on it own unless I come to a complete stop?
OK, this is exactly
what I have been experiencing. It has been occurring for years, but it's so intermittent that until that dealership dude walked in on my drive shaft diagnosis, there was no hope of showing the problem to anyone at Jeep. As a result, I did get them to replace the rear drive shaft and had hoped the problem was solved, but no such luck. One night a few weeks later, while simply driving home at night, it occurred again. The new drive shaft just seems to have altered the circumstances under which the condition is excited.
I now have the opinion that the bad u-joints that we're seeing aren't causing
the vibration to occur; they're being caused by
whatever actually is causing the vibration which is, I think, something further up stream than the u-joints. My buddy was working on another wk (v6 gasser) with vibration issues and got someone at Jeep to tear into it. They never really did solve that
problem...a transmission shop ultimately diagnosed the issue as a chattering torque converter lock-up clutch which was continually vibrating on and off with a frequency similar to a telephone ringing (vibrate...smooth...vibrate...smooth, etc., the whole time the car was being driven). This was not the same issue that I've (we've?) been seeing, but in the process of Jeep's tear-down, they also discovered a loose/partially chewed splined coupling between the transmission and the transfer case. They repaired the coupling and associated parts...and then decided that they were done working on the vehicle. Needless to say, that
car still has its torque converter issues, but it started me thinking that perhaps there is a near-blanket issue of this sort (loose coupling buried between the transmission and TC) that, once it's excited into vibration mode (by road surface variations, etc.), manifests itself at the mechanical resonant frequency of the rest of the drive train. The resulting vibration, at least on my car, is certainly violent enough to cause u-joint damage like that which we are seeing. This could explain why some folks are going through multiple drive shaft replacements...the u-joints aren't causing
the problem, they're being ruined by
the problem. Food for thought...
The (not so) funny part: as I'm writing this, I'm preparing to go to my Jeep dealer to pick up my WK. It's been there for week now on its second swirl-motor/intake-flap repair in a little over a year, and there is still no end in sight on the vibration issue. This WK has to be the most unreliable new vehicle purchase that I've ever made, and that's really saying something as I bought a couple of new FIATs back in the early 70s, and they
were everything you've ever heard about...and less!