Cruiser Shakes Violently - more scary stuff!

[Altaf]

I don't think issue is related my other thread about shocks, but on occasion my Cruiser develops a very violent shake and feels like it could just fall apart!!! I can't reproduce it and it happens very randomly, about once/twice every couple of weeks. Basically the entire trucks starts to violently shake/vibrate while going straight. It feels like it's being caused by the drive shaft or something underneath the Cruiser and not the tires or axles.

I don't think the shake is associated with engine rpm as I've placed the Cruiser in neutral and mashed on the gas while the shake was occurring without effecting the severity of it. The shake usually starts as I'm accelerating past 40 mph, and if I let off the gas, the shake becomes much more violent. If I make a sharp turn the shake usually goes away. I can also slow down below 35 and drive for 50-100 yards and the shake usually goes away.

I took the Cruiser to a generic repair shop (not Cruiser specialist) but they couldn't reproduce the shake or find a problem. They told me they greased the drive shaft and the shake didn't occur for several weeks after that, but it just happened again over the weekend. I'm probably going to drop the Cruiser off at the Toyota dealership this week but would like to know if anyone else has experienced this. BTW the suspension is stock but the tires are slightly larger 285/75. Thanks.

 

[Ebag333]

Check all of your suspension/steering nuts/bolts/linkages to make sure they're tight. Then get your tires balanced. If neither of those works, then it'll be time to look at other things.

 

[spdwaver]

If you are thinking that it is a driveshaft, then could it be the u-joints?

Did you remove either driveshaft recently?

Are the tires properly balanced? Larger tires can cause this when unbalanced, but not always as random as you say it is.

 

[Ihasfip]

I don't know how crucial the steering stabilizer is on a Cruiser, but I know on a 80's model fullsize Chevy or any 4x4 solid axle Dodge it can cause that. A customer of ours 2000 2500 Ram 4x4 was doing it ever so often, similar circumstances, and with the swap of the steering stabilizer the problem was cured. Just some food for thought.

D

 

[Ebag333]

I've driven without a steering stabilizer. Barely noticed. (Seriously, had to pay very close attention and couldn't even tell all the time even then.)

A properly setup vehicle should not need a steering stabilizer. They will help take up some of the play in a vehicle, and help dampen a bit of vibes, but they shouldn't be required. If it won't drive properly without one, then there's a larger problem that the steering stabilizer is simply masking.

 

[mudgudgeon]

this is really common with lifted 80series particularly with big tyres.

I'd put money on it being due to worn panhard rod bushes, even if they look Ok, they can still be the cause. change them with genuine toyota or silmilar rubber bushes. Make sure all panhard bolts are done up TIGHT.

also check for worn tierod ends

 

[zombified]

have you gotten a recent alignment? this certainly sounds like deathwobble. is this condition brought on by bumps?

 

[hdj81v]

check the front panhard/lateral rod bushings.

 

[jonheld]

A violent shake is most likely wheel rotation related. Driveline vibrations tend to be more of a buzz as the driveshaft is spinning 4x faster than the tires.

I would put the truck up on a lift or jackstands and check for play at all 4 corners. Be certain to look at the steering knuckle bolts on the bottom of the housing. As mentioned by others, check all steering linkages for slop. There should be none.

Could also be as simple as tire balance. If you knocked a wheel weight off, you'd start to notice it around 40mph or so.

 

[Altaf]

I haven't touched anything related to the drive shaft/steering or suspension components. The tie rod ends were replaced 2-3 years ago. It doesn't feel like the shake is coming from the steering based on the steering wheel feedback or even the tires. It's more like the entire chassis is shaking. Road condition doesn't affect it either and I really can't duplicate it as much as I've tried. I recently did a 500 mile road trip and the Cruiser didn't shake even once. That's how random this is.

 

[Atticus]

Could it be a motor or transmission mount?

Definitely check for play at all four wheels.

 

[Tools R Us]

The most common cause of death wobble on the '80 is panhard/track bars. Most often from loose bolts, but could be a bad bushing.

 

[Altaf]

Forgive the ignorance but can someone post a pic of the panhard. I'm looking for it in the FSM since the Cruiser is at home.

 

[Tools R Us]

Lateral control rod. Check the torque on the two bolts holding it on, 127ft-lb.

 

[Tools R Us]

When under there with the torque wrench, my drill is: Also click the arm to axle and frame bolts, then reset to 75ft-lb and check the 4 lower knuckle nuts on each side.

 

[Altaf]

Thanks for the clarification. I will check this out and report back, hopefully tonight.

 

[Altaf]

Well the lateral control rod (panhard) bolts were already tight. I guess there's no way of knowing if the bushings are worn unless I remove the rod. The bushings look like they're not going to come out easily or go back in without some serious convincing. What do you use to get those puppies out and back in?

 

[tblume]

pretty sure they are press fit to the panhard, may be obvious after pulling the nut and washer if the bushing is toast.

 

[jonjem]

The most likely problem is the swivel hub preload. If there is not enough preload on the king pin bearings the slightest bump will create a violent shake and the only way to stop it is to slow down. I have experienced this on may vehicles, even a new pootrol the the dealer couldn't fix. Quick fix drop shims, proper fix rebuid swivel hubs. Hope this helps.
Jon

 

[crowt]

I had a very similar issue to this in my 97 landcruiser. After much testing I also determined that it did not seem to be related to engine speed. What did seem to trigger the start of the wobble was accelerating over an uneven road - i'm not talking a dirt road but just crappy highway pavement - the wobble would seem to start in the rear of the truck and gradually work its way forward, intensifying almost like a resonant frequency, untill the entire dash, seats, and occupants were vibrating like crazy. I would pull over have a look underneath - see nothing, and drive away as normal. This would happen once every 3-4 weeks.

While trying to diagnose I pulled up slightly on the park brake while driving and felt a similar vibration but much less violent.

I tore into the rear wheels to look at the calipers and brakes, they were A- OK, then I popped the rear disk/drum off and the park brake parts inside were completely seized on the drivers side rear wheel. I removed all the parts including those on the back side of the wheel, replaced some, re-lubed some (good thread here for that) had the inside of the drum resurfaced. Put it back together - and never had the wobble again in 2 years of driving.

I actually drove around for quite a while with all the park brake parts removed from the drum - and did not have the wobble. This might be a good test for you, it's pretty easy to take it all out - putting it back in is the tricky part - but it's not that bad.