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Diagnosing Death Wobble and Fixing Non-DW Shimmies and Wobbles

144K views 217 replies 72 participants last post by  TheSecretSavage 
#1 · (Edited)
The Inspection Checklist is in Post #5 of this thread.

Most people would benefit from watching these two videos. The videos are kind of long at 18-19 minutes each. Hopefully, they are thorough enough to help.

PLANMAN explains Death Wobble Diagnosis and Inspection Jeep JK Wrangler Part 1 - YouTube
Part 2, PLANMAN explains Death Wobble Diagnosis and Inspection Jeep JK Wrangler - YouTube

I'll start out by explaining that Chrysler decided to use a 14 mm trackbar bolt, with a trackbar bushing sleeve designed for a 9/16" bolt, and the trackbar bracket bolt holes are somewhere around 15-16 mm large. This is a sure recipe for DW if the trackbar bolts are not properly torqued and periodically re-torqued to 125 ft. lbs.

Stock JK bolt in stock trackbar bracket hole - YouTube

HITMONEY suggested I do a Death Wobble Write Up Dept. thread.

It is a good suggestion because my DW posts are buried in other members' threads and in some PMs.

So, here are some of my posts and PMs regarding DW.

I will also include info on non-DW shimmies and wobbles in the thread.

I will clean it up as I go, but it should be helpful nonetheless.


Death Wobble is no mystery.

It is caused by loose bolts, damaged components, or improper installation.

Look at the picture below and follow along:



First, the tie rod (green) has ends that attach to a knuckle on each side. As you could imagine, if either ends of the tie rod were broken or bad, that could be a culprit for a shimmy (not Death Wobble). A common place to damage the tie rod is on the driver's side at the adjusting sleeve (in the picture, just to the right of the red swaybar link). That sleeve (maybe not the correct term for it, but you can see what I am talking about) allows the width of the tie rod to be expanded or contracted. There are threads on that end that can be damaged, causing play on that driver's side and allow an up and down, or circular play movement. Again, this would cause a shimmy, not Death Wobble.

Next, look at the drag link (purple). On one end, it attaches to the pitman arm (lavender), that attaches to the steering gear box. On the other end, the drag link attaches to the passenger side knuckle. When you turn your steering wheel, a shaft turns that goes to the steering gear box. The steering gear box turns the pitman arm, and the pitman arm pushes or pulls the drag link, which pushes or pulls the knuckle. Your steering wheel is straitened by loosening the two nuts on the sleeve/turnbuckle on the drag link and rotating the sleeve/turnbuckle to lengthen or contract the length of the drag link. If either end of the drag link is damaged, this would cause a wobble or shimmy, but not Death Wobble.

Next, look at the trackbar (aqua). It attaches to a bracket on the frame on the driver's side and to the axle on the passenger side. The purpose of the trackbar is to center the axle on the frame. With the axle centered on the frame, it provides some resistance to the steering system to allow you to turn. If there was no trackbar and you turned the steering, the whole front frame would shift. As a result, there is significant force applied to the trackbar in driving and steering.

Now, imagine that the bolts that hold the trackbar are loose in their bolt holes, or that the bolt holes are wallowed out (oval), or that the bushings at the trackbar ends are damaged, or that the bracket at the axle side has come loose because the weld has broken, or that the bushings are all twisted up because the rig has been lifted without the installer loosening the bolts and then retightened them at the new ride height. All these things would allow play in the front trackbar. When you steer or go around a corner, these loose or broken things would allow the axle to shake or slide side to side. If you hit a bump in the road, it could knock the trackbar towards the driver's side. Then, the rest of the suspension (springs, etc.) would try to bring the trackbar back to the passenger side. If you were going at any sort of speed, you could develop a kind of harmonic resonance as the axle more and more violently slide/rocked/shaked from side to side. It would feel like your whole front end was being voilently torn apart. You would have to bring your vehicle to a complete standstill to stop the harmonic resonance. This is Death Wobble.

Even one incident of violent Death Wobble related to the front trackbar can cause significant damage. The voilent harmonic resonance of the back and forth shaking is more than the trackbar bushings, bolt holes, and brackets are designed to handle. A severe Death Wobble occurance can crack or break the welds on the axle side trackbar bracket, or the bolt can wallow out the bolt hole in the bracket, or the bushing can be permanently damaged.

This is the most common source of Death Wobble because inexperienced installers either do not remove the bolt from the trackbar when they install a lift--leaving the bushing pinched in the bracket and bound up, or they do not properly torque the bolts after the lift has been installed with the tires on and the full weight of the vehicle on the ground at ride height, or (maybe the most common) they do not retorque the trackbar bolts after the first 50 miles, after every heavy wheeling trip, and at every oil change interval.

Next, look at the lower control arms (purple) and the upper control arms (light blue). In the picture, they are aftermarket arms with a heim joint on one end. However, the stock control arms have a rubber bushing at each end. When the control arms are properly torqued, the bushing is somewhat pinched in the mounting brackets on the axle and the frame. Sometimes, an installer will make the mistake of not loosening the bolts for the control arms when they install a lift. What happens sometimes is they really bind up the bushings because they are pinched/sandwiched at stock ride height, but then forced to the new lifted ride height. These bound up bushings can cause weird handling, bushing failure, and lead to Death Wobble. The proper way is to loosen the bolts, install the lift, reinstall the wheels so the suspension and jeep are at the new ride height, rock the vehicle/suspension back and forth and side to side, then re-torque the bolts to spec, then after 50 miles re-torque them to spec, then after every oil change or very heavy wheeling trip re-torque them to spec.


Improperly balanced tires, too much air in tires, bent wheels, improperly installed wheel spacers, bad tires (with separated plys), and poor alignment specs (caster, camber, and not enough toe-in) can cause wobbles and shimmies that lead to Death Wobble. However, these precipitate Death Wobble, but they are not the cause of Death Wobble.

Although not specifically identified in the picture, the ball joints that are at the top and bottom of each knuckle where it attaches to the axle C can go bad. Bad ball joints can cause shimmies, wobbles, but usually not full on Death Wobble.

Next, allthough not identified in the picture, the unit bearings can go bad and be a cause of shimmy and wobble, but not Death Wobble.

Hope this helps--assuming you read it all.

Death Wobble is no mystery.

The reason that the steering stabilizer masks it is that it can absorb some of the side to side voilent harmonics of a loose trackbar or damaged mounts. However, this masking is dangerous because it will not prevent the eventual failure of trackbar bracket welds and bolt holes from trackbar Death Wobble.



It is extremely important to immediately diagnose and fix Death Wobble.

Even one episode of DW can damage other components.

Multiple episodes of DW are almost guaranteed to damage other components.

Multiple episodes will often damage your:

  • ball joints
  • tie rod ends--including the adjusting sleeve end on the driver side
  • trackbar bushings
  • trackbar bracket bolt holes
  • steering sector shaft (where the pitman arm attaches to the steering box)
  • steering stabilizer
  • front lower control arm bracket bolt holes
  • unit bearings
  • trackbar bracket welds
  • drag link ends

Hellbound13 is an example of a member who with 5-6 episodes of trackbar related DW on a stock jeep ended up "chasing his tail" for many, many months. He ended up replacing almost everything in the above list--sometimes more than once.

Without repairing/replacing everything that was damaged at once, the remaining damaged components continued to cause DW problems, further damaging the remaining components.




This is Death Wobble (and the guy is extremely foolish for repeating it on purpose):

Death Wobble - YouTube
 
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1
#5 · (Edited)
Further Steps to Diagnose and Fix

NEW, UPDATED DIAGNOSIS CHECKLIST

Assuming your tire psi is 28-30, your tires/wheels have been balanced and rotated to make sure the wobble doesn't move with the rotation, here would be my order:


  1. Remove the steering stabilizer.
  2. Have someone turn the engine on and turn slowly from full lock to full lock while I visually, manually (with my hands on the components), and auditorily inspect for any play in the tie rod ends, drag link ends, sector shaft, trackbar ends/bolts/brackets, and trackbar bracket welds.
  3. Then, do the same thing but with short, sharp, quick back and forth turns of the steering wheel between the 10 o'clock and 2 o'clock positions, instead of the slow, lock to lock approach.
  4. Then, I would remove the front trackbar to inspect the bolt holes for ovaling and inspect the trackbar bushings for separation or cracking with a long screw driver through the bolt sleeve and the trackbar in a vise to leverage against the bushing in all directions. If all is good, I would reinstall the trackbar with the tires on the ground at ride height to 125 lbs.
  5. Then, I would inspect the drag link end joints by using a large channel lock wrench that gave me enough leverage to check for up and down play in the drag link ends. There should not be any meaningful up and down play. If there is, the ends should be replaced, or a new drag link with heavy duty joints should be installed. After, I would check the torque of the drag link ends. Taller lifts magnify the problems of bad drag link ends.
  6. Then, I would inspect the tie rod ends with the channel lock wrench for up and down movement. There should be no meaningful up and down play. There should only be rotational movement in the joint end.
  7. Then, I would put the front axle on jack stands with the tires about 2" off the ground and check the front ball joints by using a long pry bar as a lever under the front tires to lift them up to inspect for up and down play in the lower ball joints. There shouldn't be more than maybe 1-2 mm.
  8. Then, I would grab the top of the tire with both hands and push it towards the frame and pull it away from the frame to inspect for lateral movement of the top ball joints. There shouldn't be any.
  9. Then, I would remove the front tires/wheels and remove the front tie rod--one knuckle at a time. Then with a large wrench or vice grips, I would inspect the end for side to side play. Then I would reinstall the end and torque to spec and repeat on the other side.
  10. Then, I would remove the brake calipers and brake disks to inspect the unitbearings for play.
  11. Then, I would reinstall the discs, brake calipers, and tires/wheels and set the axle back on the ground.
  12. Then, I would support but not lift the front axle with a floor jack and loosen the front control arm bolts (upper and lower on the axle side). One at a time, I would drop the control arms to inspect the bolt holes and bushings (similar to with the trackbar), reinstall without torquing, and do the next one. Afterwards, remove the floor jack so the suspension is at ride height, vigorously rock the vehicle side to side and front and back, then torque to spec.
  13. Next, I would inspect the sector shaft that comes out of the steering box for cracking or twisting.
  14. Then, I would take a test drive without the steering stablizer to feel for any wobbles.
  15. Finally, I would reinstall the steering stablizer or spring $40 for a heavy duty steering stablizer.

If this front end inspection does not diagnose and/or solve it, then I would move to an alignment.

  1. I would use adjustable lower front control arms to set my caster spec between 4 and 5 degrees--with a cross caster that has less on the driver side than the passenger side. I would personally not do more or less, with a target around 4.5-4.7 degrees caster.
  2. If my camber is out of spec, but it is not due to failed ball joints, I would install offset ball joints to get my camber in spec.
  3. I would set my toe-in to spec on the machine--which is about a 1/16"-1/8" toe-in depending on tire size.
  4. If my front to rear alignment is off, I would install rear lower adjustable control arms to fix this.

Also, I recommend you switch out your stock 14 mm trackbar bolts for 9/16" grade 8 bolts.

See the following video for more information:

Common source of death wobble on Jeep JK Wranglers - YouTube


With all this, I highly doubt you do not find the source.

The last ditch thing if there is a non-DW, speed dependent range wobble, I would borrow a different set of wheels and tires to see if it changes, and I would try driving it with no front driveshaft to see if that changes anything.

Although it is always a good idea to inspect your axle shaft u-joints, they will not cause DW.

The most common sources of full on DW are:

  • Improperly torqued trackbar bolts
  • Damaged trackbar and control arm bushings because bolts were torqued on a car lift or while the vehicle was not at ride height with the tires on the ground. When you torque trackbar and control arm bolts, the bracket pinches the bolt sleeve in the bushing, as well as the bushing itself. If this is at a geometry other than actual ride height, the bushings are twisted/bound/pre-loaded, and they will eventually fail/separate/etc. If you have a flex joint end, this does not apply for that end.
  • Ovaled out trackbar bracket holes due to DW episodes from loose bolts.
 
#6 ·
This is a modified version of a PM to RedX08 who was fighting some wobbles:

First, I would re-align your rig with 4 degrees or more caster (assuming you have adjustable front control arms) and the most toe-in within factory specs. If you are doing it yourself using the project-jk write-up, toe-in 1/8" more in the front of the tires than the back.

Also, if you have bent an axle C and your camber is out of stock specs, this may cause some shimmy at certain speeds. You need offset ball joints to fix this.

During the alignment, I would check the tie rod adjusting sleeve to see if it was damaged to the point that it wobbles or is loose when the tie rod got bent. I would also have someone slowly turn the steering wheel from side to side while inspecting the tie rod ends and drag link end to see if their is side-to-side play. Also, with a helper turning the steering side to side, I would inspect the steering shaft (in the engine compartment), the shaft u-joints, the steering box and output shaft, and the pitman arm.

Second, I'd make sure your tire psi was somewhere between 28 and 30, and that you haven't rotated your spare to your front axle (differences in size due to the spare having less wear can cause issues).

Third, I would rotate your tires front to back to see if it is tire/wheel related (never having the spare rotated to the front). While rotating the tires, I would want to know if you have hubcentric wheel spacers from Spidertrax and that you removed the lug retainer clips when you installed the spacers. If your spacers aren't hubcentric, I would replace them. If you did not remove the lug retainer clips, that is the source of your wobble.

Fourth, I would loosen the bolts for your front trackbar and front control arms, rock the vehicle back and forth, then side to side, then re-torque everything to specs to see if it is from bushings that are bound up.

If you have had DW instead of just shimmies/wobbles, each component needs to be removed one-by-one to inspect bolt holes and bushings.

Fifth, I would inspect your ball joints by jacking up your rig with the tires slightly off the ground with the axle on jack stands. Then, while someone uses a crow bar or some other lever underneath a tire, while he person lifts up the tire I would inspect the ball joints to see if there is too much up and down play. There should be less than 1.5mm up and down movement in the lower ball joints.

Also while on the jack stands, I would grab the top of the tire with one hand and the bottom with the other hand to see rock it in and out to see if there is lateral play in the ball joints. There should be almost no lateral movement.

Sixth, while still on the front jack stands, I would remove the tires/wheels and brakes to inspect the unit-bearings to see if they have too much play.

Seventh, I would replace the tie rod with a new one--preferably a Poly Performance or Rock Krawler chromoly tie rod.

Eighth, I would sell my JKS front trackbar and replace it with a Teraflex forged front trackbar.

Ninth, I would replace my drag link with a chromoly version.

Tenth, if I hadn't gotten rid of it by then, I would sell my front axle and buy a Dynatrac 44 front housing to move my Rubi locker, gears, and my chromoly shafts into.
This did fix my wobble, but unfortunately when I came back from superlift I am having some more trouble. I am waiting for some stuff to come in and I will get it all fixed up again.
 
#7 ·
My jks track bar has worked flawless, and x2 on torquing things to 140ftlbs, or accordingly. Never one episode of dw. My friend has a stock '07 and he has dw but thinks he's smarter than the world and won't listen and swears it's the stabilizer. I'd send him this but I've sent so many to him it's a mute point at this point. Some people just won't listen and I think this is the reason for so many of these threads.
 
#9 ·
Text added to first post:

I'll start out by explaining that Chrysler desided to use a 14 mm trackbar bolt, with a trackbar bushing sleeve designed for a 9/16" bolt, and the trackbar bracket bolt holes are somewhere around 15-16 mm large. This is a sure recipe for DW if the trackbar bolts are not properly torqued and periodically re-torqued to 125 ft. lbs.
 
#14 ·
Thank You

I just wanted to say thanks for taking the time to do this writeup. This is a really important issue and you've done a very nice job.

.
 
#16 ·
Hey Planman, this has got to be one of the BEST write-ups to date on the DW. Thanks Alot.......
 
#22 · (Edited)
And this isn't a sticky why?

Wish I could say following all this took care of our dw issues but it didn't. Jeep has been undriveable for a month and at this point I'm ready for some c4 and a det cord. I bought another car just so the jeep can sit idle in the carport as it was my wifes dd. At this point I'm ready to sell it and just get a trail only rig, that's all ours is good for at this point.
 
#23 ·
how is camber corrected? i have a 2.5" teraflex lift with an additional 1.75" spacer front and 1" rear. adjustable LCA's.

at this point i've torqued everything down, got poly track bar brace adn teraflex monster track bar. ball joints are new and good and tre's seem to be tight as well.
 
#24 ·
Often, out of spec camber is indicative of worn lower ball joints or a bad unit-bearing.

Otherwise, it is from a bent axle tube or C. In these cases, it is fixed with offset ball joints, or you can replace the Cs or the housing.

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#26 ·
I don't recall who sells offset ball joints. But I have seen posts here and on JKF about them.

If you read a write-up about how to replace the front axle shafts you will see how to remove the unitbearings. Essentially they are a sealed hub and bearing on the front end that contains the wheel lug studs, bearing, etc.


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#28 ·
NAPA AUTO PARTS Sells the offset ball joints. Not sure of the over all quality but they look good. Probably not as good as Polys or anything but if you need them NOW they got them or can order them same day. I looked yesterday and pretty much every warehouse in the USA had them in stock.

PS this write up is great and I absolutely enjoy reading it often.
 
#29 ·
Stupid question.... Should a properly set up front end not have DW after hitting a large pothole with no stabilizer? I know the stabilizer masks other problems but will a properly set up rig not get DW even without a stabilizer? I have DW after hitting a large pothole checked everything on the list but my stabilizer and the way I understood it is that a HD stabilizer will just mask it not stop it? Im just lost when it comes to this. Thanks :beer::beer:
 
#30 ·
I love how this is a no-kidding issue for jeepers, but that nobody I have taken my rig to has a clue on how to fix. As a novice, I bought into the "steering stab" solution (suggested by multiple repair shops) hook/line and sinker. This write-up is something I wish I would have seen a year ago. Thanks for taking the time to write this up. Off to actually trying to fix this problem.
 
#31 ·
Thank you. Please report what you find.

Stupid question.... Should a properly set up front end not have DW after hitting a large pothole with no stabilizer? I know the stabilizer masks other problems but will a properly set up rig not get DW even without a stabilizer? I have DW after hitting a large pothole checked everything on the list but my stabilizer and the way I understood it is that a HD stabilizer will just mask it not stop it? Im just lost when it comes to this. Thanks :beer::beer:
A properly set up front end does not need a steering stabilizer to prevent DW.

One of the first things you need to do to diagnose DW is to remove your steering stabilizer to make it easier to determine the source.

Steering stabilizers serve an important role. However, they are not designed to compensate for loose bolts, wallowed holes, failed ends, etc.
 
#32 · (Edited)
I added 1 1/2 inch spacers on top of my TF 2.5 inch coilsup front and got another set of 35s, and for the first time in 3 years with my lifted JK...I had DW. I had my steering stabiizer off awaiting a new one when it happened. Everything is tight, I just went through and tightened everything down. Now with the new TF stabilizer it hasnt happened again...I have a vibe in the wheel pretty much all the time, even at a stop. Have had my tires balanced twice now, and the tire places say I need hub rings..this shouldnt have anything to do with DW though right? Not sure on where to go from here. Great write up planman :beer:
 
#33 ·
I added 1 1/2 inch spacers on top of my TF 2.5 inch coilsup front and got another set of 35s, and for the first time in 3 years with my lifted JK...I had DW. I had my steering stabilizer off awaiting a new one when it happened. Everything is tight, I just went through and tightened everything down. Now with the new TF stabilizer it hasnt happened again...I have a vibe in the wheel pretty much all the time, even at a stop. Have had my tires balanced twice now, and the tire places say I need hub rings..this shouldnt have anything to do with DW though right? Not sure on where to go from here. Great write up planman :beer:
Your castor may have changed enough to need adjustable lower control arms up front.
I used an Old Man Emu 2" Heavy Duty suspension and since everyone on the forums had to use fr. lwr. control arms,I also ordered some. I installed the lift while arms were on b/o. My 09 Rubicon 4 dr. rode fine. I live in the country on winding,bouncy narrow roads,and I drove it on freeway with alot of music equipment in back. It rode GREAT! ( My factory springs had collapsed,the front bump stops were touching axle pads).
I have heavy bumpers,a Warn Powerplant,Or Fab Tire/Can carrier(5ga. water,5ga. fuel), Hi-Lift on fr. bumper,pull pal on rear,dual optima batteries and recovery gear/tools/keep ass alive stuff. So alot of weight,Corbeau front seats are lighter and Kilby rear Floor Kit is lighter than rear seat it replaced,but still a lot of weight.
I don't think I got the height that most due because of the weight,so I think caster was not an issue.
But All the OME users had slightly lengthened the C.A.'s,so I set mine at 23". Factory arms center to center were 22 5/8". So I set new arms at a 3/8" increased length.
I test drove on country road,fine. I drove with music equip. that night,hit a bump in a turn at 50 or so and Death Wobble. Then again in another turn just a few minutes later.
Took great care and didn't happen again. Next day I shortened arms to 22 3/4". Just 1/8" longer than stock. Checked re-torqued on arms and track bars front and rear,it was good.Drove almost 200 miles today,various roads,Pismo Beach/Oceano. MUCH BETTER. Can still feel it on the verge sometimes so I will shorten to stock length and then get an alignment. Still using factory 32"'s,39,000 plus miles!, and wanted to wait on alignment until new tires,but I think it is worth getting done anytime you change ride height.
 
#36 ·
I had an alignment done and my castor was about 3.5 before alignment. They set it around 4.5 and my toe OUT was twice recommended setting so they brought it in to specs. My passengers side camber was out a bit. I don't have any more DW on the verge like before but I have a shimmy,or vibration,worse at 55-70mph,but evident at most all speeds. I have 40,000 miles on factory 32" BFG MTs and they rotated them one last time. Tread is not bad material wise but cupping etc. as usual with hi mileage MTs. I think the rotation may be an issue. Aside from getting new tires asap, (no $$$), I think I am going to reposition tires as the drivers side front has the most tread. It was the spare and always used in regular rotations but only on the passengers side. It sure sucks to go from a Cadillac like ride to a Model T like ride!
Great and informative write up,thanks guys.
Now,whats up with the TOE IN???
I have read that will cover up bad ball joints,and doesn't factory specs call for slight TOE OUT???
I am confused.
My OME lift was smooth and sweet until i replaced stock fr. lwr. control arms with adjustable arms and apparently set them too long. I got DW twice in a row hitting bumps or holes in turns at 50-60 MPH. Life has sucked ever since.
Hopefully now i just need tires.
I have gone thru most of the checks for loose bolts etc.
 
#37 ·
No. Factory specs are for toe-in. Toe-out helps when your ball joints are bad.

You can usually find take-off Rubi tires and wheels for around $500-$700. For the tires only, you would pay less. Being on a tight budget, that is a possible solution for you.

With your camber slightly off, I'd bet at least one of your lower ball joints are bad.

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#38 · (Edited)
With your camber slightly off, I'd bet at least one of your lower ball joints are bad.
I am thinking same thing mainly because of the 2 times of D.W.
I swapped out the drivers front and rear tires and it seems better,but I live in country on narrow back road so no hiway speeds yet. Checked drivers side front for loose ball joints and all was nice and tight. It's pass. side that is off camber,going to check it. Could be axle housing or C too since that is the weak side I would assume (longest).
Swapped both sides front to back and way better. Then I finally got some new tires. Unfortunately,I went with 33's even though I REALLY wanted to go 35. I could not afford to change gearing,and with a heavy 4 door auto. trans. I didn't want to deal with that!
So new BFG KM2's 33"/11.5"/17" with 1.5" (285/70/17 I think...) spacers and factory wheels. I got 6 and purchased a used wheel. This way I have 2 spares for Death Valley and 6 tires to rotate for longer life. Anyway. WAYYY Smoooth! I think I did some minor damage,cause I feel a little something,maybe ball joint(s),but otherwise really nice to have my JK back! Playing with air pressure. Running 33lbs. to start.
 
#39 ·
can a properly setup front-end have DW when running disconnected on the road after hitting a pot hole?

I use to have DW and thought it was fixed a while back after adding front/rear adj trackbars. I then added front adj lower arms and the jeep drove great! after wheeling this past weekend i left my swaybar disco'ed and experienced the DW today while going over a pot hole.

I am going to inspect the trackbar and arms this weekend but was curious if the disco could make it DW

thanks
 
#40 ·
Not full on DW like in the YouTube video in my first post.

At 10 psi disconnected at higher speeds you could have adverse handling, but not clanking DW till you stop type feedback.

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