Death Wobble Solved; Alignment, Toe-In

'92 XJ, 3.5" RE Super-Flex, 108k miles, new 33x10.5's:

There we were, driving on a Park Service road, you know -- the roads that you have to pay a fee to drive on -- the ones we exclusively entrust to the Feds to maintain -- the ones that suck... Anyway, in three different places we hit bad parts of the road causing death wobble. Twice about 30-35 and once about 50 MPH. The real DW by the way, I didn't scream like a girl or mess my pants, but my hands tingled for about five minutes afterward, probably from hanging on. Oh, and stupid me, the first time it happened, thinking I was on a motorcycle I guess, I accelerated -- just made it worse -- had to slow to under 25 to get rid of it.

After adjusting the toe-in I believed I solved the DW problem or at least I could not duplicate it on the same road after making the adjustment. Before the adjustment, I had one full inch of toe in (calls for zero). I was stupid not to have realized this earlier because when I would back it up, the bottom of the tires would push out -- enough to notice. It also wanted to understeer in extremely tight turns. It does neither now.

I also found a hub with just the tiniest bit of play. I'll replace that.

Thanks to these posts for being the most helpful in diagnosing the problem:

http://www.naxja.org/forum/showpost.php?p=244065960&postcount=2

http://www.naxja.org/forum/showpost.php?p=519236&postcount=8

the toe out of spec may have just amplified a condition that was already there. usually something has a little too much play and the toe not being where it should be just amplified the problem.

be sure to check all the joints in your front suspention and steering for excessive play.

stewie said:

the toe out of spec may have just amplified a condition that was already there. usually something has a little too much play and the toe not being where it should be just amplified the problem.

be sure to check all the joints in your front suspention and steering for excessive play.

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Great...

Not what I wanted to hear. Well, I'll check everything a third time, but I wasn't able to see anything moving. Guess I'll start by taking off the drag link and track bar so I can better inspect the ends... And of course replace that hub.

Thanks.

You probably already did this, but I'll ask the stupid question anyway. Have you laid under the vehicle while somebody cranks the steering wheel (like a quarter of a turn) back and forth looking for free play from the tie rod ends all the way through to the steering box? Track bar too!

check your balljoints too, they cannot be tested visually though you need to jack it up till the tires till theyre like 3 inches off the ground then put a pry bar under one and try to lift it up while looking at the ball joint, see if it goes up. Mine had like a quarter inch of upward play, this ruined my tires, made some lugs wear faster than others since the tires were like jumping on the road

winterbeater said:

You probably already did this, but I'll ask the stupid question anyway. Have you laid under the vehicle while somebody cranks the steering wheel (like a quarter of a turn) back and forth looking for free play from the tie rod ends all the way through to the steering box? Track bar too!

Click to expand...

Check...

emr1101 said:

check your balljoints too, they cannot be tested visually though you need to jack it up till the tires till theyre like 3 inches off the ground then put a pry bar under one and try to lift it up while looking at the ball joint, see if it goes up. Mine had like a quarter inch of upward play, this ruined my tires, made some lugs wear faster than others since the tires were like jumping on the road

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...and check.

Both done earlier today, and yesterday...

Thanks for the help though.

stewie said:

the toe out of spec may have just amplified a condition that was already there. usually something has a little too much play and the toe not being where it should be just amplified the problem...

Click to expand...

I'm going to say you're probably dead right here. While on a different road, traveling about 50, I hit a bad patch of pavement and I felt a little wobble, not bad enough to jerk the steering wheel back and forth and before I was able to react to it, it went away on it's own.

When I was at a shop getting a new muffler, I had a guy who's been working on Jeeps for over 20 years look at it and he didn't see a problem with the ends on the track bar, drag link, or tie rod.

The hubs are here now, so I'll replace those when I put the gears in. Hopefully that'll do it.

theres a list floating around of stuff that causes dw, track it down, and check things off one at a time.

threads like this only tell you what solved OTHER PEOPLES dw.
loose tracbar bracket was the cause of mine.

xcm said:

theres a list floating around of stuff that causes dw, track it down, and check things off one at a time.

threads like this only tell you what solved OTHER PEOPLES dw.
loose tracbar bracket was the cause of mine.

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From my first post, excerpts listed below, there's two posts referenced that have the lists you mention. From these lists the hub is the only thing I've noticed loose. I'm hopeful changing the hub will solve the problem.

The mechanic that looked at my Jeep said the trackbar end on the frame side is the most common culprit, so you're not alone...

wbt said:

...I also found a hub with just the tiniest bit of play. I'll replace that.

Thanks to these posts for being the most helpful in diagnosing the problem:

http://www.naxja.org/forum/showpost.php?p=244065960&postcount=2

http://www.naxja.org/forum/showpost.php?p=519236&postcount=8

Click to expand...