Violent Shaking

[crown14]

Also I will add that panhard isn't your problem. Panhard, radius arm, and rear link to chassis bushings can all cause the "death wobble" (among other things, worn out swivels, etc) but that is NOT what you have described here.

If you have actually taken the tires off and checked them, and the lugs weren't loose, then you need to check your driveshafts. If what is going on is as violent as you describe it shouldn't be so difficult to find. Elias' above story would be the exception.

 

[mbrummal]

can you elaborate on why you prefer polybushes to rubber? To borrow a line from another thread, explain to me why I should buy one instead of the other.

I believe this has to do specifically with panhard rods bushings only. Recently, the genuine ones have been really crappy and don't last long at all.

 

[p m]

If you have actually taken the tires off and checked them, and the lugs weren't loose, then you need to check your driveshafts. If what is going on is as violent as you describe it shouldn't be so difficult to find.

... and that would be more pronounced under load.

 

[D Chapman]

Dan, can you elaborate on why you prefer polybushes to rubber? To borrow a line from another thread, explain to me why I should buy one instead of the other.

I don't, I like rubber. I hate poly actually. Thing is, the rubber bushings are just simply not lasting right now. I've never had a problem with rubber before until about 1.5 years ago. I can't keep the rubbers in my truck. They just fall apart. So I switched to polys and so far everything has been cool. But I prefer rubber.

 

[D Chapman]

Also I will add that panhard isn't your problem. Panhard, radius arm, and rear link to chassis bushings can all cause the "death wobble" (among other things, worn out swivels, etc) but that is NOT what you have described here.

If you have actually taken the tires off and checked them, and the lugs weren't loose, then you need to check your driveshafts. If what is going on is as violent as you describe it shouldn't be so difficult to find. Elias' above story would be the exception.

This is just simply not right.

My panhard ron bushings failed and caused sever, violent, shacking. Three times. First time I was chasing the problem by checking pre-load, having the tires balanced, rotating the tires, etc... Then I got stranded 20 miles from home because the truck was not drivable. I could not get over 10 or 15mph without the truck feeling like it was about to shake apart. That's when I noticed the panhard rod bushings. I had to tow the truck home on my trailer.

3 months later, same thing.

1 week later, after driving 1,500 miles to Texas and doing some wheeling, same thing.

In Texas I robbed a panhard rod off a junk truck to get home. Those bushings lasted right at a year when the death wobble started to show signs of coming back. That's when I put the polys in. They have not been in long so I'm still on the fence about them, but they did fix my wobbles.

The last time I replaced the panhard bushings with rubber bushings, I also replaced the radius arm bushings. They were genuine. I don't have a pic of the panhard bushings, but they looked just like these when I took the rod off. These bushings were less than 9 months old.

 

[Tugela]

Alright, this is helpful. Narrows down the discussion a little. Selective application of polybushes, it's an interesting approach. I didn't realize there was a change in quality of the rubber bushes.

That photo doesn't tell a thousand words, more like just 4: those bushes are shot.

 

[crown14]

Dan were those RTE radius arms with new bushings or were they factory original radius arm bushings? Because the quality of the radius arm bushings a couple years ago wasn't far off the quality of the panhard rod bushings, and if the radius arm bushings are compromised like those obviously were, then once the panhard bushes went the axle would start wrapping and the truck would shake due to driveline angle. Steering would also get a little weird, etc. But only if both the panhard bushings and the radius arm-to-axle housing bushings failed/were failing at the same time, which is slightly more likely than cats breaking up and sometimes clogging the exhaust, but still not very likely at all.

If your rad arm bushings are good now, go out and loosen the bolts on both ends of the panhard rod and go for a drive.

 

[D Chapman]

Stock radius arms and panhard.

All bushings have been replaced more than once, and on one occasion all at the same time the same day. I basically tore the entire front end apart the first time this happened and replaced the radius arm and panhard bushings, replaced a suspect TRE, and rebuilt both swivels. This was about 1.5 years ago when I was getting a "shimmy" in the steering wheel. Not long after that is when I got stranded and Nomar had to come get me so I could get the truck and trailer to get home.

I went through two more sets of panhard bushings and a set of radius bushings before going poly.

Loosening the panhard blots would probably only affect steering by making it sloppy. I don't think loosening the bolts replicates worn out bushings. And by worn out bushings, I mean falling the fuck apart bushings. There was literally 1/2" of movement.

 

[GregH]

Agreed on the panhard rod bushings most likely culprit.

I am one of the few people here who did not like the rubber bushings and I switched over to poly in the mid-90's after replacing rubber bushings several times. I found the rubber bushings started allowing my suspension to get "wallowy" in as little as 10k miles. Part of that may be because my '89 RRC did not come with sway bars so the bushing firmness is more noticeable. I also found the rubber bushings more difficult to press in and I had to use a large press to get them in. The poly ones I can press in with my large bench vise.

The common refrain is that the rubber deteriorates slowly and the poly delaminates suddenly. It's true.

The key to using poly is use plenty of lube. That allows the poly bushings to "slide" against the metal surrounding it rather than tearing.

Despite the lube that comes with the bushings, I buy a big tub of the Energy Suspension lube and use liberally on all contact surfaces of the bushings. It does not come off easily and is waterproof, etc. I just wipe off the excess after installing. This stuff:

http://www.energysuspensionparts.com/Energy-Suspension-Formula-5-Prelube-Bushing-Lube.asp

Even with the lube though when they go bad they will delaminate fairly quickly so you need to check your bushings every time you change your oil and after every off road trip. If you see delamination, pull and replace.

The bushings I find I replace the most are the rear trailing arms and I can pull and replace those in about an hour.

The only place I've left rubber bushings is the rear top link assembly-I don't mind the extra movement there and it is a bitch to get to anyway.

 

[Cris_rrc]

The other day I was driving my RRC and the whole truck started to violently shake at speeds over 15ish mph, after reading some threads I guess I will replace the swivel pins. Is there anything else I should look at replacing while doing the job? Or is this really the problem.

Thanks,
Robert

I didnt read the entire 2 pages of everyones comments but I had the same problem , ended up being 2 things , panhard bushings and my steering box was loose that's the mayor cause of the violent shacking , after making tight every bolt the shacking went down 70% I will say , check those out as well.

 

[AU_88]

Update. I started with the bearings a while back, that did not fix the problem, today I changed the steering damper and the vibration went away so far. I am still going to do the bushings, but at least I can drive the truck somewhere to have that done. It's hot as hell here.

 

[AU_88]

Well I drove the truck around tonight and the vibration is still there, now when I come to a stop though the headlights grow dim and idle plummets, give it a little gas and the lights get brighter and it comes back to life. When I stopped before pulling in the garage it completely died... Alternator? Something else?

 

[mbrummal]

Vss affecting the idle?

 

[AU_88]

Vss affecting the idle?

Could be, but it is definitely losing electrical power. The headlights dim at idle, the lights in the truck go down. I had to give the truck gas at the stop lights to keep it running on the way home.

 

[mbrummal]

Is it idling low? If it is, the alternator might not be able to keep up.

 

[AU_88]

When it died the other night I pushed it into the garage, then it cranked right up. The headlights get dimmer and brighter in correlation to rpms, i.e. as the revs go up the headlights reach normal brightness and when the revs get below 1200-1300 the headlights get dimmer until the truck loses all power. It barely started for me the other night and I have been having issues with the battery going dead. I may call you mason in the next couple of days.

 

[mbrummal]

Sounds good.

 

[AU_88]

Well the panhard rod bushing have been changed and had no effect on the shaking. What's next.

 

[p m]

Have you checked your driveshafts as Joel suggested?

 

[Cris_rrc]

I had shaking and was unbalance tires, what about steering damper and have you tightened all the steering box bolts?