92 YJ SOA death wobble? steering? help!

[dukabor]

All,

Asking for a little diagnosis help here.......

92 YJ SOA, MORE SRS w/Buggy Springs, MORE Hi-Steer, RE 1.5' springs
running on 36' bias swampers on 15x8 alum rims (BB Balanced)

approx 4 degrees of caster

Running without track bars or swaybar

Installed 4 months ago, always had a slight wobble at 35-45 mph, 2 days ago it became a large wobble, could still accelerate through it, but was needing attention.

Got home, checked toe in, was good, swapped tires (maybe one was out of round, or bent rim). Rebuild 4 months ago also included all new bearings in front end, 4:88 and No-Slip install up front.

Up in the air, there is side to side play in the steering , making me think
I may have a steering box going bad........any thoughts?

The front end U-joints are all good, and there is no play in the steering shaft........

Fill my weekend up........tell me what I may have missed.......

Thanks in advance for any help you can provide!

[jeepik]

just cuz you got new hub bearings doesnt mean they are still good


i see a couple of things to check here


is your steering box tight on the frame???

check your ball joints

check your hub bearings

other then that you got bias ply swampers so expecting a smooth ride is not something you should expect :)

[dukabor]

Thanks jeepik,

Yep, box is tight on the frame

Ball joints replaced 4 months ago, and still good, no play

No play in the hub bearings

I have spent the last 5 years with a variety of swampers up to 40" on daily drivers, and I live with their renown 'ride quality' :sousy: - but the wobble has now become a concern.

All the rod ends are tight, no visible cracks or bends in the drag link or tie rod.........

[mckeddie]

let's see what all i checked on mine. ball joints, steering (heims on mine, probably check you TRE's.), how much slop in your steering? still did it with the other tires? i would say probably your bearings having some slop then. pull it all apart, and check it all. mine ended up being a busted belt (tire rotation cleared it up, now i just don't drive on the street till i get a new set). can't think of anything else, i'm getting pretty tired.

greg

[abotros5]

i also have a severe wobble...and im real new to this jeep thing... i read about the death wobble on the FAQ forum but i didn't really understand anything they said or anythin that goin on in this post... could someone plz help me out, or should i just take the jeep to the stealership? how dangerous is the death wobble?

[wcjp]

abotros5

You're death wobble will be a very different animal than an older Jeep's. The older one's have springs all the way around. With your coil springs I couldn't begin to tell you what to look for. Ask Stu Olsen or other experienced TJ person in the know.

A SOA on an older Jeep is changing the relationship of the axle to the spring. Stock YJ's and CJ's the axle sits on top of the spring. A SOA moves the axle to below the spring. This usually nets at least 5-6" of lift.

[abotros5]

wcjp,

i do have a lift on my jeep, im not sure how much, but i think it might be a 2 or 3" suspension lift. also, it only got real bad after i got myself stuck in mud...im not really sure whats up with that. how dangerous do u think it could be to drive around with? like is it a problem that can be ignored for a while, im kinda short on money and i have inspection comin up at the end of this month, still need to fix my cracked manifold, bad O2 sensors, and cylinder misfires

[Janster]

How long are your shackles up front??

How tight/loose do you have them torqued to?

What is your TOE allignment set to??

You should be set slightly TOE OUT .

4 degrees caster isn't much....
Is it worth having the knuckles cut & rewelded to get more caster???
I really don't know... you should talk to other SOA guys first.

If you were to rotate the knuckles - that would also rotate your entire steering set-up. Will this be *better* for handling??
Again, something to ponder....

What about traction bars... You really might need them to get things under control. I've seen A LOT of rigs with SOA and trac bars.

This is another reason why we want to stay Sprung under.... to keep things more drivable.

Good LUck!

[dukabor]

Solution part I

I replaced the rod ends (showing signs of wear) on the drag-link and tie rod, and balanced all 4 tires, and it seems to have gone away. Evrything else is in good shape (bearings, ball joints, etc)

Solution part II

Bought 5 new steel rims for my 33" radial street tires, will save the 36's for the wheelin trips.

Solution part III

re-installing the sway bars for street use


Janster......a couple q's

I have a MORE shackle reversal, and why set to toe out?, stock specs show for a set to toe in.......and with larger diameter tires, to equal that, shouldn't more toe-in be required (in theory) ??

stock caster is 6-8 degrees, in the grand scheme of things 2 degrees may not be much, but taking all the other mods into account it may be part of the problem.

The reason we went with 4 degrees of caster was the option on my RE springs of moving them forward 1.5 inches (extending wheelbase, more room in back of fender for flex) and this adds about 2.5 degrees of caster (same effect as shimming)

and you mention traction bars, this should not have anything to do with the wobble, I think you mean trac-bars, I may decide to run an adjustable one on the street as well.

[mckeddie]

my caster is set at only 3.5* i don't have any probs related to that. i was always told by the local shops that 3.5 was about standard on most (they've done many swaps, but not any jeeps). of course, mine is still SUA with the full widths though. you may want to check your shackle bushings too, that is what the other prob with mine was that i couldn't think of. sounds like you already got her taken care of though. hope all goes well fro ya.

greg

[Janster]

-=- originally posted by dukabor -=-
Janster......a couple q's

I have a MORE shackle reversal, and why set to toe out?, stock specs show for a set to toe in.......and with larger diameter tires, to equal that, shouldn't more toe-in be required (in theory) ??

stock caster is 6-8 degrees, in the grand scheme of things 2 degrees may not be much, but taking all the other mods into account it may be part of the problem.

The reason we went with 4 degrees of caster was the option on my RE springs of moving them forward 1.5 inches (extending wheelbase, more room in back of fender for flex) and this adds about 2.5 degrees of caster (same effect as shimming)

From our own experience..... after our axle swap, we had major death wobble. I don't know what specs require - but when we set it to slightly toe-out, the death wobble went away completely.

Our front axle (dana 44) only had .5 degrees caster on one side and 1.5 on the other side... We had our knuckles cut and rewelded to give us 6 degrees. This is fine for us considering the cost it took - but the steering wheel does not *return to center* after a turn like it should. At the time, we had no idea where our caster should be based on our modifications - so we picked 6 degrees (stock specs).

Does your steering wheel return to center/striaght after a turn (without you holding it)??

If caster is set up properly - the wheel is tilted back enough that causes it to be firmly in place based on the physics of the steering (I can't even word this the way I'm thinking). When you turn the wheel - the wheels WANT to return to the straight position.
If you drive a car (something that hasn't been modified), you'll notice the steering wheel will always return to straight naturally ....

In a perfect world of vehicles that are not modified...that is how it should be. But once you mess with everything - suspension steering etc...it changes everything else and one thing can and will affect the other. That's why I wasn't sure if adding more caster would help your situation based on all the mods you have.

[seanyj93]

what is the degree of your drag link? if that is really steep then it will take any bump, even the small ones and even side to side motion and multiple it into the steering.
also did you say you had no track bars....that might be the prob. but i dont run them iether.
i had the wobble till i replaced with 4"drop pitman arm and high steer spacer to lessen draglink agnle.
good luck

[BrackneyC]

-=- originally posted by abotros5 -=-
wcjp,

it only got real bad after i got myself stuck in mud...im not really sure whats up with that. .

Maybe you have mud packed on the inside of the rim, causing it to be very out of balance

[dukabor]

All,

After 3 days of running on 33's on the street, I can't believe the difference!! WOW, the 36's are relegated to trail duty only (as they should be)!!

The 5 steel rims cost $45 more than the replacement of 1 swamper, and since I had 5 brand new 33's laying around, it only makes sense to run this way, I guess I was too caught up the look of those 36's!!

Bottom line is I can;t remember my ride ever being this good!!!!

[95jeepyj]

sean93yj'
what is a high steer spacer and who sells them?

jeff

[95jeepyj]

my angle is crazy!!!!

:tomato: