Is it true that if you have wobbling at certain speeds (55MPH in my case) that if the steering wheel is not moving then it is NOT death wobble, but indicative of some other problem? I was watching some YouTube videos of death wobble and their steering wheels were not shaking, like mine does not either. But in my case the whole truck seems to do a side-to-side wobble. I guess I'll find out tomorrow when I pick mine up from the shop that I had balance the tires if it was just a balance issue or something else, but I just wanted to know if I was misinformed about steering wheels not shaking if you have death wobble.
If you look out the window at the front tire and it is shaking back and forth - and the steering wheel is not... then check a few key points.
1. the rag joint where the steering rod meets the steering box (under the hood)
2. the tie rod ends
3. the kingpins
If all the components are sound, then the steering wheel should be shaking and the problem is with the tire (balance, out-of-round, popped cord, etc.).
in old El Paso...
Death wobble is usually in the suspension. It does not jerk the steering wheel, and you can not correct it with the steering wheel. Your wheels may be tracking perfectly straight, but your chassis is flying all over the place. That's one of the fun things about a live axle. You have to keep in centered under the vehicle and if you can't you get death wobble. If you have a SPOA suspension the effects increase. (weight suspended under your axel is more stable than weight perched on top of your axel) If you have a suspension lift it's effects increase (higher COG above the axel) If you have soft springs it's effects increase (amplified ability for the body to move independant of the axles) These are all things that can amplify death wobble, but they don't CAUSE death wobble.
Things that cause death wobble are :
worn out bushings in your spring eyes,
loose bolts on the eye at the shackles/hangers,
blown out shocks.
bad geometry between the T-case and the differentials.
Death wobble is when your whole chassis is undulating and rocking and it keeps getting worse and worse until it feels like the rig will flip over. A shimmy in the steering or shaking of the wheel is the steering geometry or worn components like bearings or knuckles with some play in them. Those are things that you feel in your steering wheel and those are not the same thing as the death wobble.
I have to disagree on this one, at least in part...
I have first hand experiance with death wobble between 40 and 45mph, where it violently shook (turned) the steering wheel back and forth. In that particular case the problem was a tire that had popped a cord. A normal balancing did not fix the problem, but a physical inspection of the tire showed the lump. Replacing the tire fixed the problem completely.
in old El Paso...
death wobble isn't the same kind of wobble that a problem with the tire will create. If you've had death wobble you will know the difference. You can be traveling on a flat freeway at 60 mph just fine, and then when you go to cross lanes or a crosswind catches your rig, it starts to rock back and forth... it continues to rock further and further each time it sways. If you slow too abruptly you will tip over, so you have to very gradually slow yourself to a speed that the undulations stop.
All good questions and points you each have that I should look into if balancing the tires doesn't fix it. But as it is right now, it is a stock Sami, no lift, I have no idea if the PO did anything to cause bad geometry between the T-case and the differentials but I'm guessing not, since it's all stock. The shop did call and tell me every tiire was out of balance but I guess I'll find out for myself tomorrow when I bring it home if I can get past 52 without any shaking of the vehicle. The shocks are brand new--I put them on all around a month ago, did the steering stab, too. Then it occurred to me last night that when I bought it, the spare had a bent rim with a tire that had a gash in it, so the PO obviously hit a curb or something decent enough to do that damage. I didn't know if that was the culprit as far as causing problems with suspension/steering that I hadn't even thought of.
I guess I was just trying to make sure I didn't have the wrong info as far as steering wheel not moving at all if it was death wobble. And BillJohn, your post listed things to check for if the front wheels were shaking back and forth. But what if they're not shaking back and forth? Then not a candidate for death wobble? And lastly, I don't know what to look for on the steering rag other than a rip in it? But it looked okay to me but I have nothing to base it on as far as what it should look like, other than not having been ripped/ripping. And here's a question most of you know but I don't--what or where is the kingpin? Thanks!
you want to make sure there is no slop in the rag joint. It would allow the front end to shift without steering wheel input. The kingpin is the pin on the steering knuckle that the steering linkage attaches to.
If all the tires were out of balance then you could have been picking up the vibrations from the rear end which wouldn't affect your steering, but would cause a shaking. If you have 4 tires out and your spare is messed up, this guy probably wheeled it rough, so X2 on checking your linkage for bent rods or missing bushings, etc.
Thanks Baratacus. I'm really hoping it comes back driveable (more than before anyway) tomorrow. How do I check for play? Hold the end towards the steering box, and if the the other side of the rag joint moves (towards the steering wheel) at all is that bad, or only if it moves a considerable amount? Because I think I have checked that before and there was movement. But if I recall, the whole shaft on both sides of the rag would move a little, not running, just sitting there. Is that normal, or typical of age to move some? I guess I'm curious what the parameters are as far as movement goes.
As far as the rods and bushings, I hope if there was a problem with any of that, the shop would find it. I made my concerns clear and they've had it for about a solid day plus, due to other problems besides the shaking. And they're no "fly by night" shop, so I'm thinking they'd find a problem where you suggested looking if there is one. Fingers crossed it's just the tires...
Anyway, I really appreciate your input guys
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.