Death wobble continues..

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Phils67
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Re: Death wobble continues..

Post by Phils67 »

Do you think i prematurely welded the perches on yhe new axle? 4.5° positive is where theyre at. The stock SUA mounts read positive 0.80
1967 Gladiator J2000, 1998 4.0L OBD2, T18, D20 twin sticks, D44HD/D60, Detroit lockers, 3.73s, 4wheel disc brake, FSSR, Dakota digital, etc.
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Stuka
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Re: Death wobble continues..

Post by Stuka »

I would personally have not fully welded them there yet, maybe tacked em on and see how everything lines up. But then I tend to be somebody that quadruple checks everything before making anything final. I think you will be fine, as you are keeping the same springs.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ
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Phils67
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Re: Death wobble continues..

Post by Phils67 »

Im mostly concerned with turning radius with them there as others in the past said may be an issue but since im going tall and skinny with the rubbers i may be ok i think
1967 Gladiator J2000, 1998 4.0L OBD2, T18, D20 twin sticks, D44HD/D60, Detroit lockers, 3.73s, 4wheel disc brake, FSSR, Dakota digital, etc.
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Stuka
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Re: Death wobble continues..

Post by Stuka »

Yeah, a 12.50 would rub for sure. What width wheel will you be using?
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ
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Phils67
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Re: Death wobble continues..

Post by Phils67 »

Stock j20 16.5 steelies. I think they are 7 or 8 wide iirc
1967 Gladiator J2000, 1998 4.0L OBD2, T18, D20 twin sticks, D44HD/D60, Detroit lockers, 3.73s, 4wheel disc brake, FSSR, Dakota digital, etc.

Fast Eddie
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Re: Death wobble continues..

Post by Fast Eddie »

Sorry, maybe dumb question, but why would you go with 16.5 rims and very limited and $$$ tires when 16" steel rims are readily available everywhere and many more 16" tire choices???
OMG, I know 16.5 rims were on my 1979 J20, first think I did was look for new wheels!!!! Just sayin'
Last edited by Fast Eddie on Mon Jun 18, 2018 5:58 am, edited 1 time in total.
1979 J20, 360 w/NV4500/D300 Twin Stick/3.73 SOLD
1978 Cherokee Chief W/T Levi interior, 360 Q/T. SCRAPPED
1970 Gladiator J4800 Camper Special, Buick 350, 4spd. SOLD
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Phils67
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Re: Death wobble continues..

Post by Phils67 »

I like the look of a plain white steel wheel. There are tire options out there.
1967 Gladiator J2000, 1998 4.0L OBD2, T18, D20 twin sticks, D44HD/D60, Detroit lockers, 3.73s, 4wheel disc brake, FSSR, Dakota digital, etc.
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Stuka
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Re: Death wobble continues..

Post by Stuka »

You can find plain white steelies in 16" sizes. 16.5's are getting very hard to find tires for.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ
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Phils67
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Re: Death wobble continues..

Post by Phils67 »

Image
Finally installed the 4 degree shims to correct my castor. Now my castor angle is 5.65 degrees and its a very noticeable difference how it sits with the pinion angled more downward. The turning radius feels no different to me. Took it for a test drive and it STILL has violent death wobble/wheel oscillation. It didn't change one bit, in fact, it feels worse and takes longer to stop the vibration than it did before. I am so aggravated right now with this thing.
1967 Gladiator J2000, 1998 4.0L OBD2, T18, D20 twin sticks, D44HD/D60, Detroit lockers, 3.73s, 4wheel disc brake, FSSR, Dakota digital, etc.
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Phils67
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Re: Death wobble continues..

Post by Phils67 »

Image
Maybe related to my shackle angle? (Drivers side in the pic). Possibly doing a shackle reversal may help??
1967 Gladiator J2000, 1998 4.0L OBD2, T18, D20 twin sticks, D44HD/D60, Detroit lockers, 3.73s, 4wheel disc brake, FSSR, Dakota digital, etc.
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Mustang Shooter
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Re: Death wobble continues..

Post by Mustang Shooter »

Can you cut and turn your knuckles?
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Phils67
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Re: Death wobble continues..

Post by Phils67 »

As far as when i am steering and driving? Yeah, it steers normal. If you are talking about cutting them off and rewelding them in a different position, there is no point, the castor shims turn them.
1967 Gladiator J2000, 1998 4.0L OBD2, T18, D20 twin sticks, D44HD/D60, Detroit lockers, 3.73s, 4wheel disc brake, FSSR, Dakota digital, etc.
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Mustang Shooter
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Re: Death wobble continues..

Post by Mustang Shooter »

From the pic i see a pinion angle shim.
If you put the shim in, it raises your pinion angle and causes more negative caster.
Negative caster causes the wobble.
If you are looking at your driver side knuckle from outside, the top of the knuckle needs to be behind the lower for positive angle.
If all you are doing is adding pinion shims, you may never get the positive angle needed without physically adjusting the knuckles.
When you measure your caster, are you placing your gauge on the upper surface of a steering arm?
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Mustang Shooter
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Re: Death wobble continues..

Post by Mustang Shooter »

http://www.quad4x4.com/catalog/qu40773/
Ok, i looked for closed knuckle caster shims.
Are you using something like this to correct your caster?
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Phils67
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Re: Death wobble continues..

Post by Phils67 »

Those are preload shims for the kingpins. I used steel wedges between the leaf spring and spring perch on the axle to rotate the knuckles back giving it more positive castor. I posted a pic. Everything painted green was installed today
1967 Gladiator J2000, 1998 4.0L OBD2, T18, D20 twin sticks, D44HD/D60, Detroit lockers, 3.73s, 4wheel disc brake, FSSR, Dakota digital, etc.
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Phils67
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Re: Death wobble continues..

Post by Phils67 »

Mustang Shooter wrote:From the pic i see a pinion angle shim.
If you put the shim in, it raises your pinion angle and causes more negative caster.
Negative caster causes the wobble.
If you are looking at your driver side knuckle from outside, the top of the knuckle needs to be behind the lower for positive angle.
If all you are doing is adding pinion shims, you may never get the positive angle needed without physically adjusting the knuckles.
When you measure your caster, are you placing your gauge on the upper surface of a steering arm?
The pic has the thin side of the wedge forward facing, which in turn rotates the top of the knuckle rearward. The top is well behind the bottom. Angle measurements were taken from the kingpins with a flat piece of steel across them. The upper and lower kingpins are parallel to each other. By taking measurements from both i can confirm the angle.
1967 Gladiator J2000, 1998 4.0L OBD2, T18, D20 twin sticks, D44HD/D60, Detroit lockers, 3.73s, 4wheel disc brake, FSSR, Dakota digital, etc.

fsj454
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Re: Death wobble continues..

Post by fsj454 »

To much tire pressure will not help with death wobble. Try 35 psi and see if that helps .Are you having a lot of vibration on highway . I have SOA WITH 35s and had death wobble and vibration .Put 4 degree shims better .Started with 11-4=7 Degrees . The problem I see with your shims is I think you have them in backwards from mine... PS I HAVE DANA 60 FRONT SOA
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Phils67
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Re: Death wobble continues..

Post by Phils67 »

They point the diff further towards the ground. It definitely increased my positive castor. I was thinking, i bet the preload on the kingpins is too light. Im gonna remove some shims tomorrow and see if it snugs it all up. I set it to factory spec, but with the lift and 35s its not factory anymore.
1967 Gladiator J2000, 1998 4.0L OBD2, T18, D20 twin sticks, D44HD/D60, Detroit lockers, 3.73s, 4wheel disc brake, FSSR, Dakota digital, etc.

SJTD
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Re: Death wobble continues..

Post by SJTD »

Looks like they are in there correctly to me.

Do you have enough helpers to have someone stand on the brake and a couple to rock the truck forward/back while you observe/feel for kingpin play?

Seems like the only thing left.
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'84 GW with Nissan SD33T, early Chev NV4500, 300, narrowed Ford reverse 44, narrowed Ford 60, SOA/reversed shackle in fornt, lowered mount/flipped shackle in rear.
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Phils67
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Re: Death wobble continues..

Post by Phils67 »

Not really. I work solo. I could maybe have my kid or wife stand on the brake and try rocking it.
1967 Gladiator J2000, 1998 4.0L OBD2, T18, D20 twin sticks, D44HD/D60, Detroit lockers, 3.73s, 4wheel disc brake, FSSR, Dakota digital, etc.
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