Mark W
Yep, it's true. I just don't care that much.
Tossing this out to hopefully get it into the search fodder for anyone else...
My primary '80 sees a lot of varied use. Daily driven year round, relatively high speed "rallying" on higher speed rocky trails, a bit of more technical crawling and a lot of deep muddy ruts mixed in on other trails. A LOT of moderately loaded long distance off road use. Shortest trail run for me is about 40-50 miles. Longer ones are up to 400 miles trailhead to trailhead. Usually running on the usual 35 inch trail suitable street tires with suspension that I will call "lifted but stock".
I had a rather severe case of death wobble about a year ago. Was on a raod trip so I had to put up with it until I got home, so it came on a few more times that I would have liked. Okay ZERO times would have been my real choice. A quick inspection and repair before hitting the road again saw me with a pair of of really sad TREs replaced. Problem solved.
Fast forward to a week or so ago, and.. damn... Death wobble again! This time I was close to home and only had to deal with it three or four times before I was able to roll the rig inside and look at things more carefully, but the cause was obvious. The other pair of TREs needed attention.
Got them replaced and all was good. I thought. Made a 900 or so mile round trip up past Fairbanks a little bit for a weekend at some hot springs. Coming through town at 35mph (about the speed it had happened the previous times).. THERE IT WAS AGAIN.
I focused on the panhard bar bushings. they were good. Checked out the trailing arm bushings. All happy. A bit of attention to the steering box. Nothing wrong there. Wheel and knuckle bearings of course were the first things I checked, and they were of course perfectly normal. Started getting a little irritated and knowing that it happens but really not expection it, I started looking at the frame for cracks.
Bingo! It was not the original cause, nor I assume the cause of the second bout of Death wobble. But this third time around... The panhard bar mount on the drivers side had a hairline crack all the way across the outer face, right where the "tower" drops down from the frame. There was some sort of flaw right in the middle. It was not on any weld line and seems to maybe have been some sort of tiny void or inclusion in the original metal of the stamped and formed part before it was welded on. Or maybe there is weld on the other side that I can not see after the frame was completed? In any even, this tiny spot had cratered out... *Maybe* a 16th of an inch wide by *maybe* 1/4 inch long. The crack had run from both sides of it all the way to, and starting around the ends of the mount.
I would not have expected it to open up/flex enough under normal road loads (or even heavy loading really) to allow the death wobble. But it did. I assume that the two previous episodes of death wobble had been enough to load the mount sufficiently to start and grow the cracks from each end of the imperfection that they spread from. For that matter, once it stared it is very possible the even normal loading was enough to slowly grow the crack.
I was able to get a dremel in well enough to enlarge and "v" the crack from end to end so that I could weld it up. A good hot deep penetrating weld turned out to be a lot easier to do that I expected when I first saw where it was.
Problem solved. Hopefully for the last damn time!
Anyway, if you are searching for the cause of death wobble in your '80, closely check your panhard bar mount(s) This crack was tiny tiny tiny. Very hard to see with anything other than a very suspicious inspection. But holy chitballs did it let the front end dance!
Mark...
My primary '80 sees a lot of varied use. Daily driven year round, relatively high speed "rallying" on higher speed rocky trails, a bit of more technical crawling and a lot of deep muddy ruts mixed in on other trails. A LOT of moderately loaded long distance off road use. Shortest trail run for me is about 40-50 miles. Longer ones are up to 400 miles trailhead to trailhead. Usually running on the usual 35 inch trail suitable street tires with suspension that I will call "lifted but stock".
I had a rather severe case of death wobble about a year ago. Was on a raod trip so I had to put up with it until I got home, so it came on a few more times that I would have liked. Okay ZERO times would have been my real choice. A quick inspection and repair before hitting the road again saw me with a pair of of really sad TREs replaced. Problem solved.
Fast forward to a week or so ago, and.. damn... Death wobble again! This time I was close to home and only had to deal with it three or four times before I was able to roll the rig inside and look at things more carefully, but the cause was obvious. The other pair of TREs needed attention.
Got them replaced and all was good. I thought. Made a 900 or so mile round trip up past Fairbanks a little bit for a weekend at some hot springs. Coming through town at 35mph (about the speed it had happened the previous times).. THERE IT WAS AGAIN.
I focused on the panhard bar bushings. they were good. Checked out the trailing arm bushings. All happy. A bit of attention to the steering box. Nothing wrong there. Wheel and knuckle bearings of course were the first things I checked, and they were of course perfectly normal. Started getting a little irritated and knowing that it happens but really not expection it, I started looking at the frame for cracks.
Bingo! It was not the original cause, nor I assume the cause of the second bout of Death wobble. But this third time around... The panhard bar mount on the drivers side had a hairline crack all the way across the outer face, right where the "tower" drops down from the frame. There was some sort of flaw right in the middle. It was not on any weld line and seems to maybe have been some sort of tiny void or inclusion in the original metal of the stamped and formed part before it was welded on. Or maybe there is weld on the other side that I can not see after the frame was completed? In any even, this tiny spot had cratered out... *Maybe* a 16th of an inch wide by *maybe* 1/4 inch long. The crack had run from both sides of it all the way to, and starting around the ends of the mount.
I would not have expected it to open up/flex enough under normal road loads (or even heavy loading really) to allow the death wobble. But it did. I assume that the two previous episodes of death wobble had been enough to load the mount sufficiently to start and grow the cracks from each end of the imperfection that they spread from. For that matter, once it stared it is very possible the even normal loading was enough to slowly grow the crack.
I was able to get a dremel in well enough to enlarge and "v" the crack from end to end so that I could weld it up. A good hot deep penetrating weld turned out to be a lot easier to do that I expected when I first saw where it was.
Problem solved. Hopefully for the last damn time!
Anyway, if you are searching for the cause of death wobble in your '80, closely check your panhard bar mount(s) This crack was tiny tiny tiny. Very hard to see with anything other than a very suspicious inspection. But holy chitballs did it let the front end dance!
Mark...
