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-   -   death wobble unsolved (http://www.wranglerforum.com/f210/death-wobble-unsolved-39426.html)

neo 11-07-2009 04:22 PM

death wobble unsolved
 
i have had my 1999 tj sport for 7 years now,a few months back it developed the death wobble.it has a 4.5 in susp.lift 3 in body lift .installed the lift kits in
2006 so the lift is not the problem.death wobble in tj's is common
i know people that run stock 30X950 ats and never go off road this has death wobble.


i repaired the problems i found below

1.lower ball joints were totally worn out.i replaced all 4 ball joints.
2.i had a lot of play in track bar bracket,i got rid of track bar bracket and installed a new adjustable track bar.
3.i replaced my wore out 35 x 12:50 mud kings with 35x12:50 AT"s
4.I intalled a rustys steering conversion with all new moog tie rod ends
5.i replaced my wore out rotors and pads and calipers
6.my front end alignment and tires are placed
7.i replaced my wore out steering stabilizer

i fixed a lot of wore out stuff,still have death wobble,what gives
i have never ran into a problem i cant fix.:cool:neo

neo 11-08-2009 03:46 PM

Quote:

Originally Posted by neo (Post 482188)
i have had my 1999 tj sport for 7 years now,a few months back it developed the death wobble.it has a 4.5 in susp.lift 3 in body lift .installed the lift kits in
2006 so the lift is not the problem.death wobble in tj's is common
i know people that run stock 30X950 ats and never go off road this has death wobble.


i repaired the problems i found below

1.lower ball joints were totally worn out.i replaced all 4 ball joints.
2.i had a lot of play in track bar bracket,i got rid of track bar bracket and installed a new adjustable track bar.
3.i replaced my wore out 35 x 12:50 mud kings with 35x12:50 AT"s
4.I intalled a rustys steering conversion with all new moog tie rod ends
5.i replaced my wore out rotors and pads and calipers
6.my front end alignment and tires are placed
7.i replaced my wore out steering stabilizer

i fixed a lot of wore out stuff,still have death wobble,what gives
i have never ran into a problem i cant fix.:cool:neo

8.i forgot to mention,i had a little play in my bearing and hub assembly on the passanger side,soi replaced the bearing and hubb assembly.:cool:neo

snwchris 11-08-2009 04:24 PM

Have you checked all the bolts on the front end.. CA's, Trackbars, etc...
Physically put a wrench on them & check.

I had an issue last week and my lower control arm bolts were loose.

Chris

Jerry Bransford 11-08-2009 04:31 PM

2 Attachment(s)
What are your caster and toe-in angles? With 35" tires, the caster angle should be roughly 4.5 to 5 degrees and the toe-in angle should be .15 which can be set manually by rotating the tie rod so the front of your tires are 3/16" closer together than the rears are.

Here's a good way to do that, measuring at points equal to your 35" tire's dimension. With a little care to insure you get 3/16", your toe-in setting will be as precise and correct as the best alignment machine results.

Too much caster angle can encourage DW, as can improper toe-in. Good luck. :)

Edit: The below suggestion to check the passenger side's trackbar mounting bolt hole to make sure it is not enlarged/wallowed out is right on. If that hole is enlarged, it will allow the trackbar to move which is one of the most common contributors to or causes of DW.

1BLKJP 11-08-2009 04:34 PM

Typically DW in tj's has to do with the trac bar. Had you drilled out the axle bracket to move it over before? Have you checked to see if the bracket hole is wallowed out at all so that it loosen up the bolt?

neo 11-08-2009 05:24 PM

Quote:

Originally Posted by Jerry Bransford (Post 482786)
What are your caster and toe-in angles? With 35" tires, the caster angle should be roughly 4.5 to 5 degrees and the toe-in angle should be .15 which can be set manually by rotating the tie rod so the front of your tires are 3/16" closer together than the rears are.

Here's a good way to do that, measuring at points equal to your 35" tire's dimension. With a little care to insure you get 3/16", your toe-in setting will be as precise and correct as the best alignment machine results.

Too much caster angle can encourage DW, as can improper toe-in. Good luck. :)

Edit: The below suggestion to check the passenger side's trackbar mounting bolt hole to make sure it is not enlarged/wallowed out is right on. If that hole is enlarged, it will allow the trackbar to move which is one of the most common contributors to or causes of DW.

my front alignment is correct,there is only one shop in town i trust for this
he does alignment on modified vehicals no one else will touch.:cool:neo

Jerry Bransford 11-08-2009 05:27 PM

He assures you it is correct but not all alignment shops, even the good ones, know that the caster angle needs to be decreased as the tire size increases. Many go to great lengths to restore the caster angle exactly to the factory caster angle which is not correct for larger tire sizes.

Exactly what is your current caster angle?

neo 11-08-2009 05:28 PM

i am beginning to hate my jeep,everything i replaced was truly worn out
the death wobble occurs at exactly 40 miles per hour,if i accelerate rate on thru its is ok,it only occurs at 40 miles per hour:cool:neo

Jerry Bransford 11-08-2009 05:31 PM

Wait, it ONLY occurs at 40 mph and you can accelerate through it to make it stop? If that's the case, you don't have DW. True DW is SO violent that you cannot simply accelerate through it. It sounds like nothing more than a shimmy which is generally always tire or wheel related.

neo 11-08-2009 05:35 PM

Quote:

Originally Posted by Jerry Bransford (Post 482834)
Wait, it ONLY occurs at 40 mph and you can accelerate through it to make it stop? If that's the case, you don't have DW. True DW is SO violent that you cannot simply accelerate through it. It sounds like nothing more than a shimmy which is generally always tire or wheel related.

not a shimmy the front end shakes so bad you think everything is going to come apart:cool:neo

tlrrob1000 11-08-2009 08:15 PM

My two cents... are your spring pin bushings wiped out?

Jerry Bransford 11-08-2009 11:42 PM

Quote:

Originally Posted by tlrrob1000 (Post 482928)
My two cents... are your spring pin bushings wiped out?

He has a TJ with coil springs, are you talking about a leaf spring Jeep?

Rawkon 11-08-2009 11:52 PM

can you give us details on the 7.5" of lift?

neo 11-09-2009 12:03 AM

Quote:

Originally Posted by Rawkon (Post 483115)
can you give us details on the 7.5" of lift?

all lift components been on almost 4 years now

3 in body lift
2.5 coil springs
2 in budget boost
drop pitman
longer shocks
front and rear sway bar disconnext

the problem started 6 months ago
everything i replaced was wore out.
death wobble still there:cool:neo

Jerry Bransford 11-09-2009 12:35 AM

I can tell you one more thing after seeing how you got to 4.5" of suspension lift, that the dropped Pitman arm needs to go and the OE Pitman arm needs to be reinstalled. In addition to DW, that dropped Pitman arm is also causing your TJ to have bump steer.

I'm guessing you aren't going to take that alignment recommendation seriously so maybe this suggestion won't have been worth the time to post either. ;)

Rawkon 11-09-2009 01:19 AM

On top of what Jerry said have you checked the ujoint in your axle shafts???

Jerry Bransford 11-09-2009 09:22 AM

Quote:

Originally Posted by Jerry Bransford (Post 483173)
In addition to DW, that dropped Pitman arm is also causing your TJ to have bump steer.

That was poorly worded but it's too late to edit it. Your dropped Pitman arm has nothing to do with your DW, it is however causing bump steer.

tlrrob1000 11-09-2009 10:38 PM

Ooops caught me sleeping Jerry. Have YJ on the brain.:doh:
When you replaced your tires did it start after that? They maybe out of balance. Like Jerry said your alignment maybe an issue also. Tire places usually have a hard time balancing tires that big due to their balancing machines are usually not set up for them.

neo 11-10-2009 06:11 PM

i went to alignement shop today my drag link end is shot the end that connects to the center link.rustys is sending me a new one.:cool:neo

neo 11-14-2009 11:28 AM

Quote:

Originally Posted by neo (Post 485301)
i went to alignement shop today my drag link end is shot the end that connects to the center link.rustys is sending me a new one.:cool:neo

i replaced the drag link end still death woble.the only that not new is control arms bushing the are 11 years old:cool:neo

Gary2 11-14-2009 02:01 PM

Anything with play will cause it even a worn steering box , have you checked the sector shaft for play .I built a steering box brace with a bearing to support the end of the sector shaft to prolong the life of steering boxes . I learned that trick from many years of chasing DW on a few Dodge Ram 4x4 front ends . All I ever had on my mind was stopping and doing so as quick as I safely could but then again I never had it in my Jeep but very often in a Dodge truck ( similar type of front end ) it usually started when I hit a bump at about 70 mph which was why stopping was all that I thought of doing , never tried to accelerate to a higher speed to tell you the truth. I never thought of it at the time .

rico334 11-14-2009 03:51 PM

Death Wobble and Bump Steer are not the same ? What distinguishes the two ?

350chevrolet 11-14-2009 03:53 PM

put up a pic of the front suspension so we can see if anything is obviously messed up. sometimes a second, or in this case a 3rd, 4th, ..., set of eyes helps.

Gary2 11-14-2009 04:37 PM

Quote:

Originally Posted by rico334 (Post 488100)
Death Wobble and Bump Steer are not the same ? What distinguishes the two ?

DW is a lot of Violent Shaking caseed usually by something loose or worn while Bump Steer is more of a geometry issue . The most pronounced display of Bump steer I ever had was hitting a large dip not a pot hole at about 70mph as the suspension compresses and rebounds you will notice the vehicle travels straight the whole time but as the suspension cycles the steering wheel made almost a half a turn . It gets your attention . This took place in my early days of lifting Dodge Rams which has basically a larger version of the Jeep front end and I learnd quickly that if you drop the track bar you use a drop pitman with the same amount of drop and vice versa

rrich 11-14-2009 11:23 PM

DW can occur at most any speed, it's not limited to 50 MPH. Sometimes you can accelerate through it - if you dare.

Since the alignment shop initially missed the worn drag link end, I wouldn't put much faith in their conclusions about the rest of it being tight.

Get under it, (wheels still on the ground) have a friend inside to work the steering wheel. Have the friend quickly rock the steering wheel back and forth to the extent of the freeplay.
Use your fingers - they are more sensitive than your eyesight for this - put your fingers on all the joints - drag link ends, tie rod ends, control arm bushings etc. You are looking for looseness, you'll feel it before you see it. Replace what's loose.

And - remove the bolt through the trackbar at the axle end. Pull the trackbar end down out of the way. Put the bolt back through the holes in the axle bracket - it has to fit snugly in the holes. You should not be able to wiggle the bolt side to side in the hole.

Check the bolt itself for wear - it's a special bolt with a longer than normal smooth shank - dealers have them for about $4.00. Parts houses don't have the right ones.

If there's any play between the bolt and the holes it will allow the axle to work back and forth - no matter how tight you tighten that bolt.

If it's loose - if the hole is warbled out, let us know and we'll show how to fix it.

And - look very closely at the steering box mount. It has a "pod" shaped thing that it mounts to - seems on lots of TJ's those welds aren't good. Look for a rust colored line - signs of a crack - the edges of the crack rub against each other scraping off fine particles of steel. Those particles rust, making it easy to spot the crack by the orange line.
It's easy to gusset that pod before it breaks off completely

Tip: Any place you suspect a crack - spray a thin coating of flat black on the area. Then drive it, then look for that line to develop === called a "poor man's magnaflux."


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