Death wobble after WJ swap

[tradisrad]

I’m hoping you all can help.

I am experiencing DW with my new setup and I need some suggestions. I’ve spent a ton of time searching the web and that sucks my soul right out of me and I don’t have a solution.

No DW before WJ swap

Truck setup:
D30 HP/8.25 4.10 gears.
Lift approx 4.25”.
32” tires.
Caster aprox 5*.
Toe in 1/16 garage set with alignment plates.
Metalcloak short arm & dual rate springs.
Stinkyfab high roller WJ OTK swap.
WJ knuckles and brakes.
Steering box brace.
Track bar is 5” shorter than drag link.

Mods from Stinkyfab kit:
Offset tierod ES2234R on draglink at knuckle and at pitman arm ES2233L. This was done to clear modified swaybar tabs.

Everything is tight, drag link and track bar angles are pretty close.

It tracks and drives nice on the straight away, but on sweeping corners I am getting shimming that progresses to death wobble.
I don’t have any noticeable bump steer.

 

[Anak]

My first step would be to have my tires checked for balance.

If those check out good, my next step would be to review all the new parts with the assumption that new parts are not necessarily good parts. Also keep in mind the fact that things may feel tight under tension, but as soon as tension is released slop may show up. This means you may need to remove your springs and use a jack to take weight off the axle in order to properly asses certain joints.

 

[tradisrad]

My first step would be to have my tires checked for balance.

If those check out good, my next step would be to review all the new parts with the assumption that new parts are not necessarily good parts. Also keep in mind the fact that things may feel tight under tension, but as soon as tension is released slop may show up. This means you may need to remove your springs and use a jack to take weight off the axle in order to properly asses certain joints.

Thanks for the reply. It’s been years, so I’ll have the balance checked.

 

[Black1990jeep]

I am helping rob here. We measured flex in the track bar mount when turning steering wheel. The mount flexes about 0.020 inch as we turn steering lock to lock.
Is this amount of flex inacceptable???

 

[Anak]

There are a number of variables in that picture. largely revolving around how much friction there is between the tires and the ground.

I am assuming this is the frame side mount. Does it have all bolts and bracing intact? Welded?

I am inclined to say that 0.020" of movement just from turning the wheel is excessive, largely on the basis that actual driving stresses are going to be more substantial and consequently likely to lead to substantially more movement. But I have never tried to measure mine, and again, that would go back to the variables.

It might be interesting to see how much movement you can get by pushing from one side of the vehicle and then from the other side, but again, I don't have a standard against which to compare.

I would also look for movement of the steering box relative to the frame.

 

[tradisrad]

Looks like my pictures disappeared. I’ll see if I can fix that. However, I don’t see an edit option
It is the axle side mount that is moving. Frame side seems solid.

 

[Anak]

Option to edit comes with red letters. Next month will be the annual membership drive. There should be raffle prizes.

I am surprised the axle side mount is moving. I would be looking for cracks. The passenger UCA is notorious for cracking at the welds.

Edit to add, now that I look at things, "red letters" have turned into a red banner. At any rate, being a member gets you editing privileges, as well as photo hosting.

 

[75SV1]

On one of my '98 XJs with WJ BB, the frame was cracked on the drivers side. For some reason that would cause the TOK bracket to break off over time. It cause DW. Also, Some say WJ BB causes Akerman steering scrubbing. I sort of notice it when tight turns going slow. My tires was about 10.5 wide. Also, recheck everything. On my 2000 I hit a curb driving in the snow. I did get a bit of wobble before, but not DW. One of my lower Ball joints was loose. I hope you used lower WJ ball joints.

 

[Bent]

There should be raffle prizes

There will be.

 

[75SV1]

I kind of question the 1/16 toe in. I think stock is 1/4. With bigger tires, I thought it is suppose to be more. ??? Although I deal with some that splay them a bit. ??? Also, what length on the Upper and lower control arms?

 

[ljobbins]

I had a problem with my alignment when I didn’t take into account the drag link having a separate alignment to toe in alignment. I was using angle iron and adjusting toe in perfect but the drag link was actually too far out pushing the tires to the right a bit. So on a tape measure my toe and caster were correct but I had death wobble because I didn’t catch the drag link part. It didn’t look wrong at a glance and it drove fine until I hit a bump.

 

[Ol Blue]

I had a problem with my alignment when I didn’t take into account the drag link having a separate alignment to toe in alignment. I was using angle iron and adjusting toe in perfect but the drag link was actually too far out pushing the tires to the right a bit. So on a tape measure my toe and caster were correct but I had death wobble because I didn’t catch the drag link part. It didn’t look wrong at a glance and it drove fine until I hit a bump.

Not sure how that's possible on WJ steering where the tie rod and drag link are completely separate. The drag link would only affect whether the steering wheel is straight and have no impact on the toe. The drag link being out of alignment certainly shouldn't give bump steer or death wobble.

Anyways to the OP: Do you have any adjustability in your tack bar mounts? No idea what your set up is with out seeing the pictures. Ran into a similar issue on mine since the drag link is much longer than the track bar. This means they will swing in different arcs when the suspension cycles (ie bump steer and DW). What helped me out was putting the axle side track bar mount at the highest mounting hole and the frame side mount at the lowest mounting hole, thus flattening out the track bar more than the steeper angled drag link. The golden rule of having the track bar and drag link parallel only applies when they are the same length. If they are different length all hell breaks loose because of the different arcs they move in. More caster (near 6 degrees) seemed to help as well. Good luck.

 

[tradisrad]

Thanks for the replies. Here are the pics

 

[tradisrad]

Thanks for the replies. Sorry for the double post.
I rechecked my caster and it’s at 6*. I can play with the toe a little more this weekend .
I too don’t see how the drag link would affect the toe.

 

[Black1990jeep]

Working with rob to fix this...One thought we have is to move in the toe in a turn or two of the tierod, note the original position, then test drive to see if that makes any difference at all. If it makes no difference put it back. Consider an alignment. Tightening the bolts did improve the wobble on Sundays test drive.

Comments on trying increasing the toe?

Thanks

 

[tradisrad]

What black1990jeep should specify is the pitman arm nut seemed to come loose and was retightened. I put a new lock washer on it yesterday and torqued to ~180ft lbs. have not driven it since. I am not convinced the wobble is fixed after 1 test drive.

 

[75SV1]

Working with rob to fix this...One thought we have is to move in the toe in a turn or two of the tierod, note the original position, then test drive to see if that makes any difference at all. If it makes no difference put it back. Consider an alignment. Tightening the bolts did improve the wobble on Sundays test drive.

Comments on trying increasing the toe?

Thanks

I thought I posted something on toe in. Might have been another thread. I think stock is 1/4 on stock tires. So, that might equate to an angle. So, possibly a larger tire needs a bit more toe in. I do not see any gear box brace. Also, a Trackbar brace might help. Still, I have had DW with both. I am eyeing the Swaybar setup. Can we have a side shot of the swaybar and the UCA and LCA?

 

[tradisrad]

@75SV1 I’ll take some pictures of the swaybar and control arms this afternoon.
I do have a steering box brace. I’m holding off on the track bar bracket braces a I may change or modify the frame side bracket to lengthen the track bar.
Are you experiencing DW too? What’s your set up? Any pics?

 

[75SV1]

Presently no DW. I have had my bouts. One was a cracked frame. The other one of the lower ball joints was loose. I did not tighten the nut enough. Both of these are with WJ Big Brakes and Cross over steering, OTK trackbar. One OTK was Rusty's, the present is SFR. The Cross Over steering is Ruff Stuff. I use Poly for the Bushing for the Sway Bars. From you present pictures it looks like the Sway Bar angle is to high. I am not sure if this is an issue or not. I had issues where the front end would lift, or lose steering. It would drift to the right. I was using ZJ swaybar link and no bushings on them. Anyways, I used some NAPA Swaybar links and it does fine. This is on a 2" lift. The other lift was 4.5". I have sent pics by phone to some before. Let me check what pics I have.

 

[tradisrad]

It’s raining here so hard to get good pics of control arms. They are metalcloak adjustable short arms.
Swaybar sits at ~15* up at the bracket. According to internet wisdom 5*-15* is good.