I know this sounds off the wall but I have had this odd shimmy/shake since I got this 1998 E-350 from 70mph up. I have had it in and checked over and over again for ball joints, brakes and everything else and the van is tight. I have replaced the tires and had them balanced 3 times, then I had them road force balanced and it was still there. And yes the the rims were checked. I have been down the tire and wheel road many times and NO that's not it. The odd thing is that the shimmy/shake gets a bunch better when the passenger side window is open. I know there is some kind of air shield under the van that doesn't look like it does anything that's loose on mine. It couldn't possibly be that could it. It's just a flimsy piece of plastic with those little plastic stick in things to hold it there. Could the tires be catching too much air? Is it even that? I don't get it. My friend and I were driving down the road opening and closing the window and it without a doubt in my mind made a big difference. Could someone clue me in please. It's been driving me crazy for a year now. It is always on the passenger side by the way.

 

tripled140,
it is not an easy one. Hovewer, some more info would be useful here. Is there is any change when brakes applied shortly at constant speed? When sudden gas increase at constant speed? Turning left/right at constant speed? At what speed it is observed? Is there vibration on the steering wheel, or all in the body? Do you feel like air pressure inside is sort of pulsating or not?

Sometimes it can be quite simple, thought. When I bought used E-150 1 year ago, I find the metal-to-metal noise from exchaust during acceleration at the lights. And so I thought it is one of metal parts inside muffler got loose and vibrating producing noise when throttle wide open. I did not change it because it did not bother me so much to justify the expence. However, eventually, after 1 year, I found that the problem is that one of the weldment points on the heat shield on the resonator that came loose. Heat shield was making the noise. After that, 3" worm clamp and few minutes all it took to fix the problem.
----------------
den25

 

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OK, here is everything I have observed over the pest year. The vibration comes on around 70mph (sometimes sooner if the wind is blowing at me). It seems sometimes worse on perfectly flat paved roads. If I'm accelerating as I gradually turn right around a long sweeping corner over 70 it gets worse. The brakes have no effect on it. I have tried putting it in neutral at high speeds and it's still there. The vibration is without a doubt coming from the passenger side. It shakes the wheel a little (sometimes never). It feels like the passenger tire is bouncing up and down like a bad rim or tire but they have been changed and re changed and rotated with no change in vibration. Very cold temps seem to make it slightly better (maybe not). I have changed rotors twice with no change. I have changed tire pressure and it does make a difference only because the tire bounces less when it has 80lbs. in it because it's harder. I have had 3 Ford techs work on this for a full day looking at every part with no fix. It drove them nuts. If I ever figure it out they want to know. They didn't even charge me a penny for the day.
Thanks for the reply.
Dan

 

those are good observations. Look, if both pressure in right-front tire and turning right at high speed affecting vibration, it must be someting with that wheel. I mean, both Pressure and Turning, are changing the parameters of the oscillator represented by wheel bouncing:
1. up-down (degree of freedom allowed by suspention),
2. left-right (degree of freedom allowed by freeplay in ball joints/tai rod end/other steering components)
3. vobling, shimming, (degree of freedom allowed by limited stiffness or freeplay in the wheel bearing/ball joints in I-beam)
Pressure makes the wheel harder, as you said, wherefore changing the interaction between wheel (ocsillator here) and the road (external force applied to oscillator). Turning changes the force applied to the bottom part of the tire in vertical and horizontal (left-right) directions.

By changing/rotating tires/wheels, you ruled out the oscillation type (1), but not others.
So jack up the right front wheel and check carefully for ANY freeplay by shaking and turning the wheel in vertical/horizontal directions. Try to tight up the wheel bearing, you can make it tighter then normal, for the road test only (beyond that, the bearing can be overheated). Sometimes, adjusting the nut on the bearing helps only temporarily (100 miles or so) because of the wear of the shaft in the steering knukle or internal/external rings of bearing. So the bearing can be adjusted but later is loose again. Bearing can be a triky problem.
Again, if there is ANY freeplay of the wheel, even commented as "There's aint nothi'g wron' wit' that wheel", vibration can suddenly appear at surtain road conditions (grade on the road, or inclined road), vehicle load/distribution of load, tire pressure, turning, acclelerating/bracking (this one is more typical for FWD car).
Den25.

 

So do you think it could be the shocks? I don't think the Ford tech's could tell if the shocks were bad by shaking the wheel. I will say that I have personally had the truck up off the ground and checked for play and never found anything. I even used a pry bar to see if I could make anything move. As far as the shocks go, it's so hard to tell if they're bad because the truck is so stiff. It's has a 9600lb GVW. I can feel every single bump in the road. I think that's why I can feel the vibration better on smooth roads. So like I was saying, it's hard to tell if the shocks flutter or over bounce because it is so stiff.

I'm thinking it's not the steering because I put a damper on it in the hopes that it would be fixed and it did nothing. If there was any side to side movement in the steering I would think that it would have gotten a little better with the damper. The wheel bearings are good. I did do the rotors twice. The second time I did them I tried to tighten the nut a bit more than needed to see if that did it and it didn't so loosened it back up to spec.

The ball joints were checked and re checked and they are good.

There is a small clunk in my wheel when I am turning at slow speeds or stopped. I'm not sure what that is.

I know that mine is not the only van to do this. My friend has the same truck with a diesel and it does the same thing but worse. Could there be a bad wheel bearing that you could not feel by shaking? I would think a bad shock you could not feel until your moving. But why would it get worse on smooth roads? I'm lost with this and it's makes it aggravating to drive. I have a 1000 mile trip coming up and I don't want to deal with this the whole time.
Thanks for all your input.
Dan

 

Check the wheel bearings and also consider the drive shaft balance.

Gene

 

looks like you have been thru lot of stuff already. Buy the way, your E350 is standart rear wheel drive, right? If so, there no drive shaft in the front (see Gene W Reply).

I would check 2 things, thought:
1. Check the right front shock absorber, and it's mounts. Not on the vehicle. Remove it, and check by hands if it moves smoothly, without jurking, and it is tight. If it is moves loosely in the center of travel, and then picks up the resistance, it might leaked out and therefore bad. Check for the model of shock absorber, if it is not OEM, watch out (I got once small amplitude bouncing problem with Monroe Sensatracks struts on Escort, the shocks designed to be SOFTER in the middle, very annoing, could not stand it, and put OEM istead). Bad shock may explain your observaition "Very cold temps seem to make it slightly better". In cold whether, liquid in shocks gets heavier therefore making shocks STIFFER, especially in the beginning of the trip. Then shock heat up, and become kind of normal. In any doubds, put the new ones (seems like Bilsteins are popular here on the forum). I would not put new OEM, as they might be too soft for the heavy vehicle you got. Make sure you mount it tightly as freeplay in bushings may prevent vibration damping later on.

2. Check if hubb/rotor/bearings sit on the shaft tightly and there is no wear on the steering knuckle shaft - on which the hubb is mounted. BTW, did you changed the hubb/rotor, or just resurfaced? Did you changed the bearings as well?

Den25

 

No need for it to be 4 wheel drive to get what feels like shimmy from the drive shaft. It is a pretty common problem with these vans, as are lack of lubrication in all of the front end joints and loose / worn / under lubricated wheel bearings.

Gene

 

Dan, the new powered balancers only spin at about 25mph, so they are only balance at 25mph. This means that it will be acceptable to 55mph. If it's not getting a small shimmy until 70 then you found a good tire shop. Take the van to a speed shop and have them balance the tires for 125mph. That should clear it up.

 

[QUOTE=Gene W]No need for it to be 4 wheel drive to get what feels like shimmy from the drive shaft. It is a pretty common problem with these vans, as are lack of lubrication in all of the front end joints and loose / worn / under lubricated wheel bearings.

Gene,
there is no drive shaft in front in those vans, UNLESS it is custom 4x4 van from www.sportsmobile.com or simular place. May be you mean the freeplay of bearings on the steeing knuckle shaft? But this got nothing to do with the "drive shaft balance" as you posted in message #7.

den25

 

Check tie rod ends for wear??

 

Den25,

I thought I posted in plain english, but apparently not. I didn't say or suggest that there was a drive shaft in the front of the van. The normal drive shaft to the rear wheels are notorious for balance problems. You are assuming that the problem is correctly diagnosed as shimmy originating from the front wheels. I am not.

A drive shaft out of ballance can feel like the problem is originating in the front as can other problems that are originating in the rear. In fact, when my van was new, it had a vibration in it that seemed to come from the front, it was speed related and was noticable both when braking and not braking. The dealer chased it for a while, balancing wheels, replacing rotors and bearings, checking the wheels to see if they were bent, warped or out of round and finally found that the rear brake drums were out of round and out of balance. Correcting this corrected the problem. They too thought it was origiating from the front end of the vehicle.

So repeating. I haven't suggested that the van has a front drive shaft, but there are a number of issues that these vans have that COULD be causing what is percived to a problem comming from the front end. Most have been covered in this thread.

 

Gene,
sorry for misundertanding. BTW, sometimes I am slow to get even plain english, as beeing non-english origin. I did not even spoke english 6 years ago.

And yes, I think the tripled140 vibration problem is originated at front since it is affected by turning right, and the pressure in right front wheel. But who knows. I do not know what to think, thought, about it getting worse when window is open.
And the comment about unbalanced drive shaft in the rear shaking front is good. I imagine now the whole frame is like big kinematic system connected to the body thru rubber dampers, shaken by 4 sprung wheels interacting with the road. Good to keep in mind

den25

 

Alright guys. I tried some things you guys said and I think I'm on to something. I tried to tighten up the wheel bearings and it seemed to make it better. Now I can feel how out of balance my drums are. I'm thinking that it was a combination of both. I think the bearings fixed up the front but now at about 80mph the rear end seems to be doing all the vibrating. After tightening the front wheel bearings there is still a little bit of play. Does that mean that I need new bearings. I would imagine if they were loose for that long that they would beat themselves to death with all the vibrating. I did put new drums on this truck twice now and it seems that all the aftermarket ones are junk. The Ford dealer found them to be out of balance before so I took them back and now I have the same problem. I'm getting tired of taking these things off. The dealer showed me how bad they were. They had it up on the lift and took the tires off and ran the truck up to about 50 and I thought it was going to shake off the lift. Then they put new $400 Ford drums on and it was smooth all the way up. I just can't bring myself to pay that much. I looked up some stuff online but I'm not sure that they are Ford parts and I don't want to deal with this again with cheap ones. Any ideas?
Thanks