Death Wobble (Losing My Mind!)

I thought I had my Death Wobble tracked down to a worn-out steering shaft joint (not the u-joint, but rather the pin+isolator that joins the upper and lower halves). I finally got my new PSC XD box in the mail and I installed it this weekend, alongside a brand-new Mopar steering shaft, with no difference at all :confused: I am still getting the typical road-induced DW about ~48 MPH.

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I'm officially stumped at this point - I'm looking for some feedback and a sanity check for something I may be missing and hoping you guys can help!

Background: When I parted out my 98 TJ, I transferred my steering (Currie), axles (D30HP/44), and suspension over to my 06 LJ. On the TJ, I never had any issues - no DW, no wander, no quirky steering - smooth as butter. I even took a video of it to show Dale how smooth it was at highway speeds:

When I bought this rig back in April, I drove it about 40 miles to my house and promptly began working on it. There was no DW experienced in that time, but there was some clunking and general looseness consistent with a rig that has been wheeled with but not much maintenance.

Current State: the axles had all new Spicer balljoints, brand new SKF unitbearings, and control arm bushings (at the top of the housing) when I built it last year. All have been rechecked and appear fine. I am running RE control arms with their "Super-Flex" joints which I rebuilt originally when I installed these in my TJ and then checked + regreased when I transferred them to the LJ (after a few thousand miles, there were in perfect condition - even with a handful of wheeling trips under my belt). Previously on my TJ, I had a used-set of 35" Grabbers on a set of steelies. Currently running brand-new set of 35" MT/Rs on a new set of ProComp 069 alloys. The lift springs were a set of 3.5" "triple rate" RK's and are now a set of 4" ProComps.

Before moving to PA, I took the Jeep down to @starkey480 at least 2 times, taking the Loop 202 and driving 70-75 MPH without any issue. I also took it to Scottsdale without a single issue with DW. The DW appears to start out of nowhere taking the Jeep for a quick spin around the block (literally getting DW for the first time about 300 yards from my house).

What I've checked/confirmed up to this point trying to track this down:
- "Dry Test" - after performing this a handful of times, I was able to track down the joint at the above-mentioned steering shaft. Nothing else can or has been noted.

- Track bar: seems tight and both the joint and bushing appears to be solid (it's a Rubicon Express RE1600 trackbar). I installed the original TB frame mount bolt with a washer (since that's how it came on my TJ) but removed it and retorqued the bolt properly after double-checking the RE instructions that I found online. Currently torqued to 55 ft-lbs at the axle and 115 ft-lbs at the mount per RE instructions.

- Alignment: I have not yet taken the Jeep to an alignment rack. I adjusted the toe when I installed it on the TJ but have not yet checked toe on the LJ (I originally set the toe between 1/16" and 1/8" toe-in). Swapping the 3.5" RK springs to the 4" ProComps would had some toe-in, but that seems like a VERY thin margin of error if 1/2" of suspension lift would significantly change the DW characteristics of the rig.

The wheel is perfectly straight (I did slightly straighten the drag-link to center the wheel after swapping steering over to LJ). Tracking down the road is straight and the wheel remains perfectly centered.

For caster, I checked both sides under the axle "C" and got the following:
View attachment 268645
View attachment 268646

To my eyes, it shows what I would expect (~4.5º on the driver side and ~5.5º on the passenger side, which is consistent with what most people target with 35" tires). No major disparity that would suggest a damaged axle housing or twisted tube.

- Wheels/Tires: these were balanced at my local Discount Tire back in Arizona. I've had nothing but good luck with this location - they're notorious for nailing balance and won't typically just add a slab of stick-on weights to get you out the door. The tech's will remove and remount tires to get the best balance possible - I know this b/c I've seen them do it on at least 2 occasions (peeking at them through the lobby glass). If the road is super smooth and I can get past 50 MPH, the tires are very smooth and drive nicely at 70 MPH. IMO, there does not appear to be a tire balance issue.

- Steering components: the Currie Currectlync is in good condition, with all parts tight and double-checked. I am currently not running a steering stabilizer and don't intend to (I will be adding my PSC hydro-assist as soon as I get this DW issue under control).

- Suspension components: control arms have been checked and double-checked. Torque at the frame and axle mounts is to spec and the jamb nuts are tight. I even unbolted all the joints and re-torqued them down just to confirm there wasn't something binding, causing an issue.

My next steps:
1) confirm toe-in adjustment
2) rotate wheels/tires (with my spare tire in the mix) to see if there is any noticeable changes
3) Sell the LJ and go put a deposit down on a new Sasquatch 6-speed :ROFLMAO:

Any advice is greatly appreciated...
You didn’t mention checking the jamb nut on the front TB.

Tires may be out of round.

Ball joint could be bad.

I only read the first page of thread, so I apologize if I’m repeating
 
is that not the most notorious tire to keep right? just about everyone that has them says how super critical the balance is and often needs changed for some odd reason.
This is imperative as well as tire pressure. If the wheels and tires are out of balance, or the tire pressure is dissimilar, you will have vibrations and wobble, not necessarily death wobble.
 
In stock form, there is pretty high interference for that press fit. You need to restore that somehow. Are you working on the hydro assist?
Yes, my plan is to hook up the hydro assist again. I didn't want to hook it up and cause the assist to mask (or worse, exacerbate!) an underlying issue.

While I'm thinking about it, I misplaced the bolt + nut for my steering bracket. Is the bolt inside the red rectangle just a standard 2.5" x 1/2" fine thread Grade 8 with a Nyloc? The local hardware store has no fine threaded Grade 8's so I'm going to need to run to Scranton this weekend and want to make sure I get the right hardware. I couldn't remember if you used a Nyloc or a metal-lock style nut...
bolt.JPG


Thinking about my options at this point and it seems like I can do the following:
1) Press the bushing back in and tack weld on the inner shoulder to keep the bushing from popping out. This doesn't seem ideal since I'm guessing that getting enough heat in there to get a proper weld will certainly cause some issues with the polymer in that bushing

2) Cutting out the "barrel" in the current bracket, then welding in a new barrel with the proper ID to ensure a good press-fit of the Clevite. Probably the most "proper" way to do it that I can think of.

3) If I'm cutting things out, I know the Currie kit is generally well-liked and seems to be about the same amount of work as #2 above. I honestly don't know how well JJ's hold up to east-coast salt, so while this does seem to provide a performance upgrade, I will need to see if there is any reliability issues.

My current limiting factor is that I don't have any 220v outlets in the garage (or nearby!) to use my welder. My option would be to purchase the biggest 110v welder I can find (~140A) and use that to weld in the new mounts. These brackets seem to be <1/8" thick, so using the 1 Amp = 0.001" Rule of Thumb for carbon steel MIG welding, I think a good 140A should work for me.
 
Yes, my plan is to hook up the hydro assist again. I didn't want to hook it up and cause the assist to mask (or worse, exacerbate!) an underlying issue.

While I'm thinking about it, I misplaced the bolt + nut for my steering bracket. Is the bolt inside the red rectangle just a standard 2.5" x 1/2" fine thread Grade 8 with a Nyloc? The local hardware store has no fine threaded Grade 8's so I'm going to need to run to Scranton this weekend and want to make sure I get the right hardware. I couldn't remember if you used a Nyloc or a metal-lock style nut...
View attachment 268837
The bolt in the red rectangle is a 5/8" x about 2" that goes in the draglink clamp. The two washers go on the inside of the tabs for a bit more room for the rod end body. The nut is a Grade C top lock. The nylocs are used on the 3/8" bolts for the clamp and front edge brace.
Thinking about my options at this point and it seems like I can do the following:
1) Press the bushing back in and tack weld on the inner shoulder to keep the bushing from popping out. This doesn't seem ideal since I'm guessing that getting enough heat in there to get a proper weld will certainly cause some issues with the polymer in that bushing

2) Cutting out the "barrel" in the current bracket, then welding in a new barrel with the proper ID to ensure a good press-fit of the Clevite. Probably the most "proper" way to do it that I can think of.
I pop the bushing out and find a piece of exhaust tube that is a press fit on the main part of the bushing. Cut that to length and tack weld it in with an old bushing for alignment. If nothing else, that will give you a lot of surface area for some stud and bearing retainer squirted in there.
3) If I'm cutting things out, I know the Currie kit is generally well-liked and seems to be about the same amount of work as #2 above. I honestly don't know how well JJ's hold up to east-coast salt, so while this does seem to provide a performance upgrade, I will need to see if there is any reliability issues.
The Currie kit is okay. If I didn't have to move away from the OEM bushing, I wouldn't.
My current limiting factor is that I don't have any 220v outlets in the garage (or nearby!) to use my welder. My option would be to purchase the biggest 110v welder I can find (~140A) and use that to weld in the new mounts. These brackets seem to be <1/8" thick, so using the 1 Amp = 0.001" Rule of Thumb for carbon steel MIG welding, I think a good 140A should work for me.
 
If I didn't have to move away from the OEM bushing, I wouldn't.
Can you expound on this part of your response?

You say that you have to move away from the OEM bushing. I assume that implies replacement of “worn” out clevite bushings with new still aren’t up to par with what’s desired for the builds taking place?

I thought the differential housing bushings would be held in the same regard as the control arm bushings. That a Johnny Joint taking their place firm up the deflection/movement and afford a tighter controlled union…
 
Can you expound on this part of your response?

You say that you have to move away from the OEM bushing. I assume that implies replacement of “worn” out clevite bushings with new still aren’t up to par with what’s desired for the builds taking place?

I thought the differential housing bushings would be held in the same regard as the control arm bushings. That a Johnny Joint taking their place firm up the deflection/movement and afford a tighter controlled union…
I have more issues with the small JJ not being durable or as durable as I'd like which I believe is due to their size. I've never had a single issue with a mid arm single upper with the larger JJ's.
 
I have more issues with the small JJ not being durable or as durable as I'd like which I believe is due to their size. I've never had a single issue with a mid arm single upper with the larger JJ's.
Understood. Thank you for the clarification…
 
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I ordered some new bushings - got an AC Delco version and a pair of Moogs just to see if there was a size difference. The AC Delco's are actually about 0.002" smaller than the new Moogs in the samples that I got.
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Went to my local exhaust stop to see if they can make me some sleeves to do what @mrblaine suggests. For $10 and less than 20 minutes later, I got 3 sleeves (in case I screw up 2 of theM!). I figure it's worth the effort to at least try to keep the OEM bushings...
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Still need to figure out a small 110v welder - time to hit up marketplace or ask around to see if anyone has a 110v hobby welder I can borrow to tack these in!
 
Found a guy selling a lightly used Lincoln "Easy MIG" 140A with cart, bottle, gloves and a spare auto-darkening helmet for a reasonable price, so I'll finally be able to tackle this repair this week and hopefully get back to driving around next weekend.
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I got everything measured out - the width of the XJ D30HP bracket was a fraction over 1" (1.051" to be exact), so I trimmed my center section to 1.055" to give me a little wiggle room for a good trim-to-tight fit. I need to get the wire wheel out and get the inside of the bracket cleaned up and ready to be welded.

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@mrblaine - when you fix the brackets like this, do you just tack weld the exhaust pipe section in there? I don't see any mechanical reason why it would need to be fully welded but want to make sure I'm not missing something here. I figure a few tack welds at top and bottom on both sides should keep it firmly in place.
 
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Found a guy selling a lightly used Lincoln "Easy MIG" 140A with cart, bottle, gloves and a spare auto-darkening helmet for a reasonable price, so I'll finally be able to tackle this repair this week and hopefully get back to driving around next weekend.
View attachment 272638

I got everything measured out - the width of the XJ D30HP bracket was a fraction over 1" (1.051" to be exact), so I trimmed my center section to 1.055" to give me a little wiggle room for a good trim-to-tight fit. I need to get the wire wheel out and get the inside of the bracket cleaned up and ready to be welded.

View attachment 272640

@mrblaine - when you fix the brackets like this, do you just tack weld the exhaust pipe section in there? I don't see any mechanical reason why it would need to be fully welded but want to make sure I'm not missing something here. I figure a few tack welds at top and bottom on both sides should keep it firmly in place.
Several tack welds but don't forget to use the old bushing to line it up.
 
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Success!!! With the exhaust tubing, I was able to get a nice tight fit. The "bump" that the exhaust shop guy put on the edge wasn't quite large enough but that didn't matter - pressing the bushing into place expanded it perfectly and it's quite solid now. I made sure to squirt some Loc-Tite in there as a "just in case" but I don't expect that bushing to cause me issues anytime soon.

I've put on about 100 miles since repairing the bushing/bracket and it drives great again. After doing some "confidence tests", I was at the point where I was trying my hardest to get DW to start and nothing. I even got up to highway speeds for about 6 miles and no issues there either (across a notoriously bumpy and poorly leveled section).