Beat the crap out of me... whining...

[gnty]

I told deaver i didn't want the bilsteins as part of the combo and would be getting Fox's with proper specs determined by Agile.
I have Fox's on my most recent Ujoint and think they are a great combo, and those are just off the shelf ones.

[TomsBeast]

Bottoming out in compression, and/or rebound with give the symptoms you're describing.

I have to tell you though, without looking at it, it's almost impossible to diagnose for certain. I can share my recent experience, which might help you track down the source of your van's malady.

I'll bet the Agile guys, with a bunch of offroad experience, can help.

I've gone through this stuff on a couple rigs, several drag racing cars, a Samurai rock crawler, and most recently on my E350 4x4.

In the case of my Van, I diagnosed the problem by putting masking tape over the rubber bump stops, and wrapping tire wrap 'tattle-tales' around the shock shafts, then took it for a drive. Turns out my front suspension was bottoming out on the factory front bump stops, not the shocks. I also found that my shocks were almost always topping out during rebound, *particularly on the overpass highway transitions*, and especially when towing.

When hitting the overpass transitions, the rear was ok, but the front would compress, sometimes hit the factory Ford bumpstops and sometimes not (not bad, 2" of rubber), but almost always would 'top out' at full extension, when the front of the van would pitch up. Topping out the shocks was particularly bad since the shock's internal up stop is likely only 1/2" rubber, and halts upward motion pretty abruptly.

One way to deal with my issue on my van could have been to just use a stiffer valved shock, which works by slowing suspension travel speed, restricting travel during fast bumps, like on the highway over the highway transitions. The only problem is stiffer shocks (valved such that movement is slowed down) can make the ride feel kinda stiff, depending on what valving you choose. I've driven some stiff shocks rigs over fire trails before, it can be a bone-jarring, filling loosening experience. In my case I didn't want stiffer shocks, I just wanted to free up both ends of the suspension travel (time consuming and expensive).

I hope that helps give you some ideas of what to look for on your rig.

[ctb]

GRUMPY!! So sorry about the Iowa roads!!! I thought maybe you got us mixed up with an Illinois road!!!! I have a Quadvan set up with airbags and dual bilsteins on the front...air at 65 psi (most generally) and have a great ride....has to be something (relatively) cheap you can do to fix...as the experts on here (are they smart or what!!! Except, Boywonder, his pic for post freaks me out a little)...they have great suggestions that will fix it!! I wonder how long a Fox Shock fix would take? A great excuse for heading out to their shop...maybe they'll buy you lunch too! Good luck and DON"T GIVE UP THE SHIP!!

[MadScience]

I had the bouncing out of control feeling on freeways for a while. It turned out that I had ripped one of the upper rear shock mounts out. That meant that there was no dampening on upward travel on one side. Scary.

It took me a while to figure out what was happening since the shock just went back into the correct spot when the van was sitting level.

The (stock) upper mounts are just washers through sheet metal and don't really seem up to extended off roading. I ended up putting a bracket like this in place with a good sized backing plate on top: https://www.summitracing.com/parts/exp-690002/overview/

Also, are you sitting on the overload leafs in the rear all the time? That will contribute to stiffness, but should help with handling. (I'm in this situation myself and have gone back and forth on fixing it.)

FWIW, I drove home last night after a long and very bumpy trail, and was more unhappy with the handling than usual. This has been a common occurrence, and I'm starting to wonder if there's a mechanical cause, (leafs going through full sway and binding? - shocks overheating on the trail?), or if it's just that I'm that much more aware of what it's doing.

[Steve_382]

Plus 1, or maybe 5 on the tire pressure. It can make the rig go from uncontrollable to not too bad. I run 52 all around, but mine weighs 4,000 front and 4,000 rear. I put Bilstein shocks on instead of Ranchos, but not sure that made a huge improvement. Maybe a little better on the highway. My door tag says 60 front and 90 rear. No way.

[larrie]

This thread is great. Am always surprised at the depth of knowledge on this forum.

The freeways in the mid west are not maintained to the standards on the west coast. When I brought our new van back from Georgia the worst roads were in Missouri, Illinois, Kansas, and Nebraska. Big pot holes in the travel lanes and very rough road surface.

Originally Posted by carringb

Weight the van, and reference an inflation chart.

Where do I find an inflation chart?

[GrumpyBadger]

Awesome response as usual on here!!

Not sure what I will do yet. The inflation is already lower than what SMB put on the charts. And, my weight is actually a little more than I stated at 9990.

Getting to CA is a bit of a stretch from WI... I'm burning all my time off this year on silly places out of the country. Not sure I will even get to drive the beasty thing again until next Spring!!! (also a reason to be thinking about selling... the lack of usage is appalling!)

I might try calling Agile anyway... I believe they will ship parts that I could have installed locally, though I am reluctant to do that kind of half measure.

Gotta do something with it...

[daveb]

Guess I'm one who saw a huge difference between the old SMB spring set and the Deaver springs. Night and day IMO. I also noticed the ride was even smoother after going to 315's.

[rltilley]

I have a 2013 SMB build & do feel that the van can be a bit tough to control on rough roads. The only time I feel that it could be dangerous is when hitting large dips at 70 mph or more. The van bounces pretty good on those. For the most part I feel the ride is decent but it could definitely be improved. I've wondered if the SMB Fox shock kit would help but I don't see too many people on here that have had it done.

My van has 60F & 80R as tire pressure on the door jam & that is what I have run them at so far. I need to get the van weighed but I'll drop that by 10 psi all around & see if that helps until I get real weights to base things on.


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[BajaSportsmobile]

Start with lower tire pressures - much lower. Ignore the door tag, it isn't relative to the tires you are running.

The problem is the spring rates and design - shocks will help, but until the springs are addressed, the shocks don't matter. Just remove them to confirm that.

Springs are much too stiff and flat.