The never ending death wobble story - remaining options?
08-19-2014, 09:39 AM
#31
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Year: 1988
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Hmmmm that's interesting...so even with Currie steering it turns right a bit, that's better than the tires toeing when hitting bumps and the suspension traveling...a solid tie rod from knuckle to knuckle would eliminate that in my opinion.
My drag link vs track bar angles are not the best but I don't think they are bad by any means
My drag link vs track bar angles are not the best but I don't think they are bad by any means
08-19-2014, 10:15 AM
#32
Beach Bum
Picture of my Currie steering, same design as stock with angle added at both TRE's on drag-link and drag-link has added arch to clear swaybar mount on axle.
08-19-2014, 10:20 AM
#33
Junior Member
That's just a characteristic of this type of steering. The only way to combat that is to have the exact same length track bar as your drag link. Crossover steering helps fight that a little as well.
Also, the more parrallel your steering links are to the axle tube the better.
Also, the more parrallel your steering links are to the axle tube the better.
08-19-2014, 11:18 AM
#34
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Year: 1995
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Just a small update (since this thread is still alive). I ordered a set of the TNT long arms that will be delivered today, installed next Monday.
I put a steering stabilizer on yesterday and it feels better enough to drive on the highway, but not exactly confidence-inspiring. I can definitely feel a lot of play in the front when I hit bumps so I am still pretty convinced it's the control arms.
That's really interesting! Based on the "too much of anything isn't good" approach I kinda figured I needed to fix my caster. The long arm Y-links should be able to set that up correctly.
I put a steering stabilizer on yesterday and it feels better enough to drive on the highway, but not exactly confidence-inspiring. I can definitely feel a lot of play in the front when I hit bumps so I am still pretty convinced it's the control arms.
Copied from here:
http://www.jeepforum.com/forum/f9/en...g-read-663777/
I know its the TJ forum but the suspensions are so close it makes sense.
*I believe* this causes instability/death wobble because big tires(33”+) have a lot of sidewall play as there is a lot more of it, so basically the entire rim is trying to wobble left and right inside the tire. German cars have a ton of caster without problems, but they have 17-19in wheels, skinny and stiff tires, and less play in the steering systems (rack and pinion vs. steering box and linkages).
That is my theory on caster angles vs. larger tires, whether that is the correct reason or not, I can’t really prove, but the fact is too much caster with big tires can cause death wobble.
It should also be noted that as you lift a TJ, because of the front control arm lengths and angles, caster decreases so it actually works out in our favor alignment-wise. I predict the problem could be more pronounced in low COG builds (example: 35” tires on 1.5” lift). In this case adjustable front upper control arms should be installed for optimum caster angles.
I’ve seen it posted around that 5 to 5.5 degrees of caster is ideal for 35” tires.
http://www.jeepforum.com/forum/f9/en...g-read-663777/
I know its the TJ forum but the suspensions are so close it makes sense.
*I believe* this causes instability/death wobble because big tires(33”+) have a lot of sidewall play as there is a lot more of it, so basically the entire rim is trying to wobble left and right inside the tire. German cars have a ton of caster without problems, but they have 17-19in wheels, skinny and stiff tires, and less play in the steering systems (rack and pinion vs. steering box and linkages).
That is my theory on caster angles vs. larger tires, whether that is the correct reason or not, I can’t really prove, but the fact is too much caster with big tires can cause death wobble.
It should also be noted that as you lift a TJ, because of the front control arm lengths and angles, caster decreases so it actually works out in our favor alignment-wise. I predict the problem could be more pronounced in low COG builds (example: 35” tires on 1.5” lift). In this case adjustable front upper control arms should be installed for optimum caster angles.
I’ve seen it posted around that 5 to 5.5 degrees of caster is ideal for 35” tires.
Last edited by apac020; 08-19-2014 at 11:20 AM.
08-22-2014, 08:38 PM
#36
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Hmmm intresting...
I may have fixed mine though, so when I adjust the caster to 7 degrees from 10 degrees it toed my tires in more.
I diddnt really bother adjusting toe but after I turned them back about 1 degree.(tried to get to stock toe @ 1/8th in) the death wobble and vibes went away!!!(so far)
The balancing beads really made a big difference with the vibes but the actual wobble was cause by the excessive toe in(maybe) I've only driven it up to 50 mph but so far so good. Will post back up wit updates
I may have fixed mine though, so when I adjust the caster to 7 degrees from 10 degrees it toed my tires in more.
I diddnt really bother adjusting toe but after I turned them back about 1 degree.(tried to get to stock toe @ 1/8th in) the death wobble and vibes went away!!!(so far)
The balancing beads really made a big difference with the vibes but the actual wobble was cause by the excessive toe in(maybe) I've only driven it up to 50 mph but so far so good. Will post back up wit updates
I really hope the long arms fix it for you man, cause then that gives me my excuse to order serious offroads!
08-25-2014, 01:29 PM
#37
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08-25-2014, 01:31 PM
#38
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Nevermind, got the wobble bad on the way home from work today. May be time to order that stabilizer just to get me through until I can get this thing driving right...
I really hope the long arms fix it for you man, cause then that gives me my excuse to order serious offroads!
I really hope the long arms fix it for you man, cause then that gives me my excuse to order serious offroads!
08-25-2014, 10:04 PM
#40
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Alright, the results are in and ...drumroll please...
Long arms rock!! Really, the on road ride is amazing, the little bumps just go away entirely and the larger one feel like the little ones. I'm not noticing nearly as much unibody flex, too - way less creak.
Now, on to the death wobble. There were 2 direct causes.
1) My UCA bushings were totally shot.
2) The tie rod end at the pitman arm had worked its way loose in the tapered insert. The insert presumably expanded and the TRE needed to be torqued down again. This happened to the TREs on the actual tie rod, which I fixed, but I didn't think to check the pitman. Derp.
Unfortunately my tires are another story. They still suck. I get a really annoying shake at 55 mph, the same one I've always had. I can either pay $100 to get them all road forced, and maybe fix the issue, or just sell them and be done with it. It's too bad because I've really liked the off road performance of the KM2s. None of the other options are as appealing (Duratrac, MT/R) and they aren't offered in 33x10.5.
Long arms rock!! Really, the on road ride is amazing, the little bumps just go away entirely and the larger one feel like the little ones. I'm not noticing nearly as much unibody flex, too - way less creak.
Now, on to the death wobble. There were 2 direct causes.
1) My UCA bushings were totally shot.
2) The tie rod end at the pitman arm had worked its way loose in the tapered insert. The insert presumably expanded and the TRE needed to be torqued down again. This happened to the TREs on the actual tie rod, which I fixed, but I didn't think to check the pitman. Derp.
Unfortunately my tires are another story. They still suck. I get a really annoying shake at 55 mph, the same one I've always had. I can either pay $100 to get them all road forced, and maybe fix the issue, or just sell them and be done with it. It's too bad because I've really liked the off road performance of the KM2s. None of the other options are as appealing (Duratrac, MT/R) and they aren't offered in 33x10.5.
08-25-2014, 11:04 PM
#41
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Alright, the results are in and ...drumroll please...
Long arms rock!! Really, the on road ride is amazing, the little bumps just go away entirely and the larger one feel like the little ones. I'm not noticing nearly as much unibody flex, too - way less creak.
Now, on to the death wobble. There were 2 direct causes.
1) My UCA bushings were totally shot.
2) The tie rod end at the pitman arm had worked its way loose in the tapered insert. The insert presumably expanded and the TRE needed to be torqued down again. This happened to the TREs on the actual tie rod, which I fixed, but I didn't think to check the pitman. Derp.
Unfortunately my tires are another story. They still suck. I get a really annoying shake at 55 mph, the same one I've always had. I can either pay $100 to get them all road forced, and maybe fix the issue, or just sell them and be done with it. It's too bad because I've really liked the off road performance of the KM2s. None of the other options are as appealing (Duratrac, MT/R) and they aren't offered in 33x10.5.
Long arms rock!! Really, the on road ride is amazing, the little bumps just go away entirely and the larger one feel like the little ones. I'm not noticing nearly as much unibody flex, too - way less creak.
Now, on to the death wobble. There were 2 direct causes.
1) My UCA bushings were totally shot.
2) The tie rod end at the pitman arm had worked its way loose in the tapered insert. The insert presumably expanded and the TRE needed to be torqued down again. This happened to the TREs on the actual tie rod, which I fixed, but I didn't think to check the pitman. Derp.
Unfortunately my tires are another story. They still suck. I get a really annoying shake at 55 mph, the same one I've always had. I can either pay $100 to get them all road forced, and maybe fix the issue, or just sell them and be done with it. It's too bad because I've really liked the off road performance of the KM2s. None of the other options are as appealing (Duratrac, MT/R) and they aren't offered in 33x10.5.
That scares me what you said about the km2s...I have brand new km2s and I'm scared there not even balancing right with the beads...
I hope you get it all figured out man! I'll post up how my upper control arm bushing are when I swap them to the polys
08-26-2014, 01:04 AM
#42
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Those km2's could just be a bad molding? Just like if a tire would slip a belt or manufacturing defects like that. If you like them a lot sell them and get another set? Then you'll know its your rims ;P
I'm glad to hear about the death wabble!
Wishing I could do some long arms... lol
I'm glad to hear about the death wabble!
Wishing I could do some long arms... lol
08-26-2014, 04:02 PM
#43
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Just took the KM2s to discount again as a last ditch effort. A different location this time, one I've used to balance them before. They turned off some "wave" setting on their balancer, and mounted them on the balancer with a 5x4.5 pattern holder. The other shop must have done a terrible job because they were out of balance, the shop today was able to zero them out. They still shake at 65, but not as bad, maybe they'll break in a little. It feels tolerable for now. I'm going to swap tires with a buddy and test when he's in town in a couple weeks, that'll be the real test of tires vs. something else.
08-26-2014, 04:18 PM
#44
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Just took the KM2s to discount again as a last ditch effort. A different location this time, one I've used to balance them before. They turned off some "wave" setting on their balancer, and mounted them on the balancer with a 5x4.5 pattern holder. The other shop must have done a terrible job because they were out of balance, the shop today was able to zero them out. They still shake at 65, but not as bad, maybe they'll break in a little. It feels tolerable for now. I'm going to swap tires with a buddy and test when he's in town in a couple weeks, that'll be the real test of tires vs. something else.
Thanks for the update
08-28-2014, 03:46 PM
#45
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Just like you man, my uca's were shot beyond belief!
I put in energy suspension bushings and new tighter hardware this morning. 90% of the wobble is gone, however I still get that nervous feeling in the tires when going 40-45 mph.
Probably Ordering ruff stuff one ton steering tomorrow so we will see if that takes care of it.
I put in energy suspension bushings and new tighter hardware this morning. 90% of the wobble is gone, however I still get that nervous feeling in the tires when going 40-45 mph.
Probably Ordering ruff stuff one ton steering tomorrow so we will see if that takes care of it.