Sometimes I wander...

dhally · 10-12-2011, 03:14 PM

No it's not Willie Nelson it's the van. After getting the high top and interior installed, the van tends to wander down the road (09 E250 2wd). Seems like it's worse than before the conversion. There doesn't seem to be excessive body roll. It has 245/75-16 Hancook 10ply running 80/65 psi. I've had several Econoline chasses, and they all had this issue to some degree.

Is this common with the newer vans? Does anybody have any secret alignment settings that will help? Any other add-ons that might reduce the wandering? I've seen some reference to a rear track bar.

UJOINT · 10-12-2011, 05:42 PM

Still running the stock shocks? If so, swap em for some Bilsteins & you should feel a difference.

frostyone · 10-12-2011, 08:12 PM

dhally,

Though I have no advice on your alignment/steering issues, I am curious if you have any photos of your new build??

KTMRIDER · 10-12-2011, 09:36 PM

Quote:

Originally Posted by UJOINT

Still running the stock shocks? If so, swap em for some Bilsteins & you should feel a difference.

That and a new steering stablizer really helped my van.

dhally · 10-12-2011, 10:14 PM

Yes I do have pictures and will post them in my build thread when I get a round tuet... now sooner since it is requested.

Stock shocks and no stabilizer. I don't claim to be an expert but the slow speed of this wandering doesn't seem like something a damper would help. It is a veeerrrryyy slow speed wandering. If it was darting sideways on bumps that would be a different story.

carringb · 10-12-2011, 11:22 PM

This is my recommended order of operations:

1) Increase caster, and also re-adjust camber which will be off now that the van weighs more. You may also need more toe-in. It's always good to get a full alignment any time a rig undergoes a drastic weight change. NOTE: incomplete vans are only roughly aligned at the factory. The Ford warranty includes a preliminary alignment during the first year.

2) increase roll stiffness. The vans have some inherent bump-steer (which is also roll-induced). This makes turn-in more car-like, but can cause wandering if the van rolls more than normal. Higher CG and increased sail area both increase body roll, even if its really isn't perceived as body roll. This can be done (in order of easiest first) through stiffer shocks, stiffer springs, or adding or increasing sway bar diameter.

3) Add a steering damper. After doing the other things, this may not be necessary. But steering dampers are also useful at reducing steering shock (which is what many folks cause bump-steer, but isn't true bump-steer from a kinematics standpoint).

I ended up doing all of the above (incl shocks, springs, and sway bars), since my van tops 13,000 pounds or 22k with trailer.

dhally · 10-12-2011, 11:52 PM

I was planning to weigh the van and get it aligned by a good shop after putting all our stuff in it. We will probably end up around 1700 lb. payload including people. Right now we've probably added 1500 lb. The back of the van hasn't gone down visually. In fact we have to park uphill to get the bed level.

I have read about adjusting the camber to be non-symetrical. The idea is that with symetrical camber, the van can't decide which way to go. Not sure I totally understand the concept. I've also had it explained that the non-symetrical camber is to offset the crown on the road.

We put a rear sway bar on our Class C motorhome and it really straightened out. But I have also read that adding or upsizing sway bars will increase jarring on uneven roads, like washboards. Any thoughts on that?

carringb · 10-13-2011, 01:55 AM

Quote:

Originally Posted by dhally

We put a rear sway bar on our Class C motorhome and it really straightened out. But I have also read that adding or upsizing sway bars will increase jarring on uneven roads, like washboards. Any thoughts on that?

When I first added a Hellwig rear bar to my van, I had the stock front sway bar with worn out rubber bushings. The ride wash jarring. When I updated to MOOG front sway bar bushings, the jarring was greatly reduced. When I swapped in the '09 front axle which has end-links instead of bushings, the jarring went away completely. So in my case, the jarring was because the rear bar was too stiff relative to the front. But now that my front bar is stiffer, it is nicely balanced, and I don't feel have jarring when I hit an off-set bump. Washboard roads still can set off some wheel hop at the wrong speeds, but I don't think the sway bars really have affected that.

dhally · 12-12-2011, 11:07 AM

Took SilVan in for an alignment and the wandering has pretty much gone. The camber was off as carringb had suggested probably due to the added weight. They had to install adjustable bushings, which was quite expensive. I thought the newer vans had adjustable camber and caster, but the shop said the factory bushings are not adjustable.

Millerfish · 12-12-2011, 12:52 PM

For what it's worth...I had the wandering front end, and after lifting the front of my 2WD a couple inches it was a bit worse. Even after the new adjustable bushings and an alignment it still just didn't like going straight. I added a steering stabilizer from a box truck and it made a big difference.
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