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Old 12-29-2020, 10:23 PM   #21
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Quote:
Originally Posted by vintageracer View Post
Coil spring conversion IS your problem.
I have coil springs and no death wobble. if you’re going to say something of this nature please take the time to elaborate why.

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Old 12-30-2020, 07:04 AM   #22
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Different animal, completely different suspension setup from what we see on any of these vans.
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Old 12-31-2020, 09:55 AM   #23
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Originally Posted by vintageracer View Post
Solid axle is NOT your problem. Coil spring conversion IS your problem.
A properly designed, installed and maintained coil spring set-up will provide a superior ride and handling compared to a leaf spring conversion, all without any hint of death wobble. Plenty of leaf spring conversions have suffered from death wobble too. The issue here is likely poor geometry, coupled with instillation issues. Best of luck......................
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Old 01-13-2021, 04:39 PM   #24
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Mg kit

I have the MG kit installed on my 2009 e350 , duel front stab , fox agile tuned shocks , i put all the recommended parts that was on the list. No short cuts and have over 1200 miles since last october. 2015 dana 60 up front and sterling e locker in the rear. Factory 2015 take offs f250,
i can eat a sammich at 75mph and style my hair, hands off the wheel.
This ride is better than new.
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Old 01-21-2021, 01:30 PM   #25
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i can eat a sammich at 75mph and style my hair, hands off the wheel.
This ride is better than new.

Post up a video, or I'm claiming it never happened!
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Old 01-21-2021, 02:00 PM   #26
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DW is an interesting topic, and damned frustrating to track down the source of and eliminate. My old slightly lifted leaf sprung Suzuki Samurai suffered it, only after I added a bunch of camping junk to the roof rack just before a trip...


My all stock 1988 F350 2wd Dually came down with a bad case of DW at 80k miles... my local tire store replaced the ball joints, and it went away.


My 2002 Russian Ural sidecar rig suffered what I'd call 'low speed wobble' (as opposed to tank slapping DW) when riding about 5mph over a parking lot speed bump. Cured it with a hydraulic steering damper. Mostly.


My current Samurai, spring over lifted, with longer Jeep YJ leaf springs (a common swap/lift), just experienced high speed DW after I loaded the back with 450lbs of Sterling axle I carried home, white knuckling all the way, having to stay under 50mph.


This rear-steer Bonneville Streamliner I once crewed on, experienced by far the worst I've seen... the first driver, very experienced guy, shut it off at 90mph and pulled off after the butterfly steering wheel tried to break his wrists. Driver #2, experience TF dragster and boat jockey jumped in and tried to 'drive through it', aborted the run at a-buck-forty...the car was cut up for scrap a month later.



All of these experiences seem to have nothing in common, until you dig a little deeper. Everything is a 'system', everything is 'squishy'. DW is nothing more than a lower order frequency coupling. Like feedback between a speaker and microphone (or guitar and amp), disc brake squeal, or for you machinists out there, tool chatter, all higher frequency but the principle is the same Watch a slow speed video of a fat lady running. There's stuff bouncing and jiggling up and down, at different rates. It ain't pretty, but it works. When body parts start bouncing at the same rate and frequency, that's when things go off the rails, and as I witnessed during co-ed softball, this larger and well endowed woman teamate of mine couldn't hold it all together. She was athletic, but big anf jiggly, after getting up to a certain speed, her stuff would bounce in time, and she would fall over on her way to first base. (How's that for a mental picture?). What was happening was 'frequency coupling'.



I contend that the same thing happens with DW, semi flexible things, tires sidewalls, tie rods, the steering shaft take an excitation (bump) start oscillating at the own natural frequency, then by happenstance 'couple', making the oscillation stack on top of another. The very worst Earthquake destruction happens like this, when the earth shaking couples with the natural frequency of a building, it's game over, she's goin' down. Yet the flimsy shack nextdoor, escapes unharmed.


I suggest that it's not coil springs, it's not leaf springs, it's not leading links or caster, it none of, and it's all of those things. That is to say, all of the components combined conspire, or not, to cause DW to occur after a jolt. Since that is based of the systems natural frequency, you can engineer something into the system that raises or lowers it's natural frequency, so the system never goes into uncontrolled oscillation (Like my softball teamate's body) You can also damp it out with something like a steering damper.
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Old 01-21-2021, 04:41 PM   #27
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I just got it in the WJ at 55 mph in a corner and it was pretty eventful. I would predict some brown pants if that had happened in the van in the same corner + speed.

I will say that my van currently has an advanced 4x4 leaf conversion with some less than ideal steering geometry, some aging parts, and doesn't have any DW. I'm a pinch worried about it doing the coil conversion but we shall see. Hanging 2 giant steering stabilizers off the front of the axle is arguable just a band aid.
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Old 01-21-2021, 08:41 PM   #28
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Quote:
Originally Posted by motovan85 View Post
I have the MG kit installed on my 2009 e350 , duel front stab , fox agile tuned shocks , i put all the recommended parts that was on the list. No short cuts and have over 1200 miles since last october. 2015 dana 60 up front and sterling e locker in the rear. Factory 2015 take offs f250,
i can eat a sammich at 75mph and style my hair, hands off the wheel.
This ride is better than new.
Did you do camber adjustment on the radius arms?
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Old 01-22-2021, 02:29 PM   #29
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DW is an interesting topic, and damned frustrating to track down the source of and eliminate.
I once had a Kawasaki Z1 that would get into bad tankslappers at speed once the rear tire was mostly worn down. A new tire always fixed it. Anyway, thanks for the great explanation, and the fat lady visual was over the top .............
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Old 01-23-2021, 11:11 AM   #30
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Enough slop can make it happen even in vehicles that ought to be immune. I actually got DW in a Mercedes 300TD, of all things. It was enough to snatch the steering wheel out of my hands. When I got home I found one of the tie rod ends had a scary amount of play in it, like "getting ready to separate and kill me" scary.
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