The vehicle in question is a 2005 Ford E350. 2wd, 85k miles.
The owner (a relative) called and said it was getting scary to drive, and it was, driftingall over and hard to control. I found it to have a lot of slop in the steering, which I traced to the steering gearbox and a loose u-joint in the steering shaft. Upon test driving after those repairs it drove much better, to the point that I thought I was finished. But then, seemingly at random, it would develop a sway at cruising speed. The best I can describe it is like you have trailer behind you that starts swinging back and forth.
I found the tie rods and ball joints to be good, the rear tires are new, the fronts are decent, tire pressure set to the door sticker specs. It was a bit breezy out, but not gusty enough to blow the van around. My thoughts are alignment and shocks, but that's just a guess, and I hate to suggest throwing money at repairs that I'm not confident will fix it. What do you guys think?
Are rear tires recommended size and specification? Mismatched front and rear tires? Loose/worn rear suspension bushings/mounts?
Jack up the front, one side at a time, and grab the wheel top and bottom and try to move it. Testing for worn out ball joints (more like king pins on the twin I-beam suspension).
Then grab tire front and rear and wiggle. testing for steering play. If those check out, take it to a reputable shop, probably the caster is out or perhaps the toe-in or Toe-out is wrong.
Edit: to say I have a 2006 E-350 that displayed similar symptoms. New ball joints and alignment fixed it.
You'd be surprised how a little wind will make a big van sway, it's basically a sail.
I have 2 older model e series and kingpins were the thing that helped more than anything
For some reason, twin i-beams love to tramline. Up one tire groove edge to the other side back and forth. I suspect it's from the long scissor action as the ibeam moves through its travel. Also cheap tires make for a E36 M3 ride.
There are about a thousand threads about this on the Ford truck forums. I have an '06 E250 and I have struggled to get it to stop swaying on the highway or anything over 45mph. I'm still hoping to get it more stable.
I added the steering stabilizer and got an alignment with caster sleeves for more caster which helped, but I am not satisfied. I plan to replace rear springs (sagging) and get more caster, plus a new steering box.
Did you jack it up and check like Indy Guy suggested? I believe the newer versions have ball joints, not kingpins. But I could be wrong.
I'd check the rear the same way for too for loose wheel bearings. It sounds like your tie-rods and drag links are good.
Are your rear springs sagging? Was the new sway with a lot of weight in the van?
How are your swaybar bushings?
What's your alignment? These vans need as much caster as possible, which involves getting caster sleeves. I recommend getting the moog units as they allow you to adjust camber too (or so I've heard). This helps because as you get more caster, the camber will go out of spec and you need a way to adjust that back. I was only able to get about +5 caster before the camber went too far neg (this was not with the moog units, which I plan to get). I want to get mine to about 6 degrees caster.
Also, what kind of steering box did you get? Some of the reman'd units are trash. Blue Top seems to be best based on my extensive research.
Add more caster. The alignment Tom put on the E250 is phenomenal. No tramlining, no sway from slight breezes, etc. I'm sure the Hellwig suspension plays into that too though.
In reply to CyberEric :
I did jack it up and wiggle the wheels top to bottom and side to side. That was all good, but I didnt check ball joints with a prybar like i probably should have.
The springs dont appear to be sagging.
It was a napa reman gear box.
I have no idea on alignment.
In reply to gearheadmb :
Here's Tom's update from when he rebuild the suspension & steering on the E250. The closer you can get to what he did the happier you'll be.
Since you don't know the current caster, I'd start with a good alignment with the moog sleeves to get as much caster as possible. My bet is your van has very little right now. I'd also double check the ball joints and get something with leverage to see if they are good. You could have the alignment shop do that too since that's needing done anyway.
I agree with everything Pete says. The rear sway bar from Hellwig is supposedly helpful in taming rear end wag. I imagine the front bar helps too, although I have heard they are back ordered. Not sure if that's still true.
Its also possible that re-man'd box is trash. Not saying it is for sure, but just that I have not heard good things except for from Blue Top. Look underneath while someone wiggles the wheel back and forth to see if there is play.
Pete Gossett (Forum Supporter) said:
Add more caster. The alignment Tom put on the E250 is phenomenal. No tramlining, no sway from slight breezes, etc. I'm sure the Hellwig suspension plays into that too though.
This. What you described sounds exactly like a caster problem. I don't know how you adjust it or how it got out of wack but I'd bet you a dozen Krispy Kreme that that's it.
I guess I don't have any issues with my '01 E350. 220k miles but the 6.8. Maybe they have different springs/bars in that?
There is something called death wobble in F350 trucks, might be worth seeing if it affects vans too.
The one small caveat to the setup on the GRM van, that is now Pete's van, is that you might want to try KYB Monomax or Bilstein B6/4600 dampers if the van is often heavily loaded.
The reason I say this is I believe it was Tom who once told me the KYB Gas-a-Just dampers on that van could use a bit more compression. The two shocks I just mentioned offer that. Pete can probably confirm (or not comfirm) that.
If your shocks are toast, that may contribute. But again, I'd start with getting more caster and then checking steering box and ball joints. These vans are notorious for only having around +3 degrees of caster stock.
