RV News RVBusiness 2021 Top 10 RVs of the Year, plus 56 additional debuts and must-see units → ×
 


Reply
 
Thread Tools Display Modes
 
Old 12-29-2020, 11:23 PM   #21
Senior Member
 
shenrie's Avatar
 
Join Date: Nov 2012
Location: boise idaho
Posts: 2,429
Garage
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.
__________________

__________________
"understeer is when you hit the wall with the front of your car, oversteer is when you hit the wall with the rear of your car, horsepower is how hard your car hits the wall, and torque is how far your car moves the wall."
shenrie is offline   Reply With Quote
Old 12-30-2020, 08:04 AM   #22
Senior Member
 
UJOINT's Avatar
 
Join Date: Feb 2009
Location: AVL NC
Posts: 998
Different animal, completely different suspension setup from what we see on any of these vans.
__________________

__________________
Chris Steuber
02 E350 7.3 (V4)
17 Focus RS, 90 SHO, 49 CJ2A, 89 LSC, 20 T250 AWD
ujointoffroad.com
UJOINT is offline   Reply With Quote
Old 12-31-2020, 10:55 AM   #23
Senior Member
 
arctictraveller's Avatar
 
Join Date: Mar 2013
Posts: 3,572
Quote:
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......................
__________________
Arctic Traveller
KC6TNI
2001 GTRV
Advanced 4wd
Agile Ride improvement package
arctictraveller is online now   Reply With Quote
Old 01-13-2021, 05:39 PM   #24
Junior Member
 
Join Date: Dec 2017
Posts: 24
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.
motovan85 is offline   Reply With Quote
Old Yesterday, 02:30 PM   #25
Senior Member
 
TomsBeast's Avatar
 
Join Date: Nov 2012
Location: Brentwood, CA
Posts: 947
Quote:
Originally Posted by motovan85 View Post
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!
__________________
1995 E350 7.3 Diesel, 4x4 high roof camper, UJOR 4" lift
TomsBeast is offline   Reply With Quote
Old Yesterday, 03:00 PM   #26
Senior Member
 
TomsBeast's Avatar
 
Join Date: Nov 2012
Location: Brentwood, CA
Posts: 947
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.
__________________
1995 E350 7.3 Diesel, 4x4 high roof camper, UJOR 4" lift
TomsBeast is offline   Reply With Quote
Old Yesterday, 05:41 PM   #27
Senior Member
 
b. rock's Avatar
 
Join Date: Jan 2019
Location: Evergreen, CO
Posts: 221
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.
__________________
'06 EB 350, Advanced 4x4 (soon to be MG), 6.7 Cummins + Allison, 18" shuttle top. Bright yellow. The rumble bee.
b. rock is offline   Reply With Quote
Old Yesterday, 09:41 PM   #28
Junior Member
 
Join Date: Jul 2019
Posts: 15
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?
desertsherpa is offline   Reply With Quote
Old Today, 03:29 PM   #29
Senior Member
 
arctictraveller's Avatar
 
Join Date: Mar 2013
Posts: 3,572
Quote:
Originally Posted by TomsBeast View Post
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 .............
__________________

__________________
Arctic Traveller
KC6TNI
2001 GTRV
Advanced 4wd
Agile Ride improvement package
arctictraveller is online now   Reply With Quote
Reply

Tags
4x4 conversion, death wobble, econoline, steering, suspension

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

» Sportsmobile Registry

Big Grey

allenl

Ann the Van

Bongo
Add your Sportsmobile
Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Sportsmobile SIP or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 03:34 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
×