Good/Bad Vibrations

[Vic Harder]

I really want to post a trip report from our adventures in Utah with our new to us Puma... but work is getting in the way! In the meantime, I have a question or two about vibrations... as in, how to control/manage them.

We drove some of the worst washboard ever on the Hole in the Rock road south of Escalante. They warned us it would be bad, but wow. Even aired down it was nasty. Speed limit is 35 mph, which is also the speed they seemed to be the worst at.... we experimented with speeds and found NOT doing 35mph was much better... but still terrible. Note that this is not a 4x4 only road... in fact, it is a well traveled gravel road.

When we got to the trail head for our hike that day, we opened the back to get lunch from the fridge and found this:

It took a while to clean that up... and while that was going on, I noticed this:

The camper literally had a few screws loose. Wow. I tightened those down and started exploring other stuff and found our Little Red Campfire was vibrating itself to bits too:

Eventually, nature called, and then I noticed that even the TP was feeling the effects of 40 miles of washboard:

I see folks posting images of nicely arranged glass jars and other bits in their cabinets and drawers... I KNOW those would NOT have survived our drive down this road.

I also know that I am moving my fridge from the very back of the camper to the middle to avoid this in the future. How are other folks dealing with vibrations/bouncing on gravel roads?

 

[Wandering Sagebrush]

Wow, that must have been one nasty road. My only solution to date has been to go really slow after airing down. Even then it is excruciating to deal with.

 

[PaulT]

Wow! That was so bad that even the photo was upside down.
Never had the fridge dump its load, but the contents of the silverware drawer at the entrance to the camper vibrated so bad one time that silverware and other contents of that drawer were redistributed all the way forward inside the parts of the cabinet with wiring & plumbing and down a level inside the door with the hot water heater. Took one of those cameras on a flexible tube, much patience, and forceps to find and extract everything from inside that area.

i have just learned to have patience & slow way down on washboard. I try to avoid washboard if possible.

Paul

 

[jimjxsn]

Wow, that must have been one crazy road. I lost the fridge contents on the old FWC with the upright fridge. I've got a chest fridge in the Panther strapped down behind the front window. We've only had minor bruising now.

And I've had all the gear from behind the sofa and the cushions in a pile on the floor. That happened this year after VoG, moki dugway and muley point. I've had the pile of gear happen a couple of times.

But I've never had screws come loose. Although maybe I'd better check...

Could be that the beefy suspension doesn't help.

Maybe you could add a better latch on the fridge door if it is an upright and comes open. Both the old FWC and the Panther have a strap and snap on the tall pantries on the passenger side. ATC used the drawer latch on the large pantry on the drivers side which seems to hold well.

 

[Happyjax]

Crazy!

 

[ntsqd]

It was pretty bad when we were on that road back in '14. I found that 42-45 mph smoothed it out, that is usually about the speed where it does, but maintaining that wasn't always safe or even possible. The worst of it occurs at a speed that is *just* short of where it smooths out. It is a rather dramatic transition in the space of just a couple MPH. Just need to have the conditions that allow such a speed and the will to push a little harder on the throttle when so far all that has done is make it worse.

My understanding of the mechanism that makes washboard roads says do not air down, that makes the build-up happen even faster. A tire pushes a "bow-wake" of loose dirt ahead of it until that wake gets too big, then the tire runs it over and it starts again. A soft or low tire pushes a bigger bow-wake. Some of the very worst wash-board that I've ever encountered is between Ubehebe Crater & Teakettle Jct. The combo of it being a steep uphill and the DVNP's ridiculously low speed limit traversed by Prius' et. al. mean that it will always be like that.

Some roads the Suck-o-Meter is just going to be pinned and there isn't anything that you do about it. But good, digressively pistoned mono-tube dampers tuned to the truck's set-up can go a long ways towards unpinning that meter. Even then we've opened the camper door to a similar mess more than once. The previous Dometic fridges needed a secondary door latch. The Isotherm's don't seem to suffer from that problem. Maybe because they're designed with boats rather than RV's in mind?

 

[Vic Harder]

Thanks for the input folks. We bungied the door shut after that incident, and still found stuff going everywhere. Beer cans in the crisper. Apples up in the top door where the beer was, etc. The bungie just kept it all from exiting the fridge.

I hope a lot of this has to do with the fridge being at the back of the camper where there is the most movement when hitting bumps.

I still marvel at the open storage I see in many camper builds. Chest/cooler style fridges make a lot more sense to me now that we've experienced this. But its the things that I can't easily modify that I want to address somehow... like:

1) Screws backing out. I think it is time to remove them all and reseat them with 3m 4200
2) Little Red Campfire vibrating to bits - foam insulation between parts?

Thom, better shocks sounds like a plan. Have you heard of such for a 2006 Chevy 3500?

 

[Ronin]

I drove the Hole in The Rock Rd as well as the entire Cottonwood Cyn Rd 11/17 and didn't have anywhere near the same experience. Yikes!! I think a couple of drawers opened partway but didn't dump anything. I had my '14 Tundra/Hawk rig at the time and I don't really remember what speeds I was going - not fast or slow, just trying to find a speed to smooth out the ride. The suspension was stock except for Ride-Rite air bags. My fridge is a Truckfridge that is held down with a Yakima bow tie down. I have had things get dumped out driving on roads where there was a lot of sideways pitching involved but I don't recall that being the case on Hole In The Rock Rd.

 

[klahanie]

Vic do you have a rubber mat under the camper ? I wonder if that might help.

I've only lost one screw in all these years, prob they're rusted in. Yours, good idea to check and the loose ones to maybe secure with sealant.

I try to dodge washboard but that can be risky. Generally slow down, never had much success speeding up to match the oscillations. Unless it was just a short patch I would air down because our truck's suspension is so stiff.

Because our fridge door is reversible it was clean and easy to add a second latch to the bottom. The fridge is small and usually packed but still use baskets inside to hep retain the contents.

For packing, in this case perhaps more stuff is better. Or rather, the less room left over the better. We carry old pieces of ensolite pad for stuffing. If I'm worried something might end up on the floor I just cut to the chase and place it there on a no slip pad.

And we've given up on dinner plates for the breakage, bowls are stronger

 

[craig333]

I've never had my fridge open but I have beers explode inside it. My other cabinets I've learned to latch securely. A cabinet maker (or pretty much anyone) would cringe at my work but it does work. I use steel plates and bowls. Not sure if 4200 is the best for those screws but it would probably work. Speeding up on washboards if you have a nice straight stretch of road.
Ever drive a road right after a dozer has driven down it?

 

[Vic Harder]

Don't get me started on exploding beers

I did end up driving faster on the washboard, which helped a LOT, but obviously not enough. I have driven on a bulldozer driven road. Ugh... that's bad... I think Hole in the Rock was worse. The other two gravel roads we did (Bullfrog/Notom and Burr Trail) were very tame in comparison.

We also did have stuff packed tightly, and used empty containers to keep things organized. Didn't seem to be enough. As everything was just getting vibrated to bits. The screws backing out really surprised me for sure.

Stuff at the front of the camper and in the cab of the truck fared much better.

We experimented with different cabinet latches on this trip too (This was a prototyping run for us. I built out the Puma shell in two weeks with cabinets, solar, charging, batteries, inverter, fridge, sink and stove... it was a rush job!) and found that the round slam latches that FWC is using now to be the best.

 

[ntsqd]

........

Thom, better shocks sounds like a plan. Have you heard of such for a 2006 Chevy 3500?

https://www.shockwarehouse.com/site/product.cfm/id/315309/name/Bilstein-B8-5100-Shock-Absorber-Chevrolet-GMC-Hummer-Front-24-186735

and

https://www.shockwarehouse.com/site/product.cfm/id/315311/name/Bilstein-B8-5100-Shock-Absorber-Chevrolet-GMC-Rear-24-186742

~$350 for all:
https://www.shockwarehouse.com/index.cfm?mode=results&selected_model=3824&selected_year=2006&type=T&selected_make=Chevrolet&model_name=Silverado+3500+4WD+(incl.+HD%2C+K3500+%26+K30)
That would get you started anyway.

Comment was made about a rubber bed mat. It was on Hole in the Rock where I realized that we really needed one. I was watching the camper do the Cha-Cha in the bed as we were driving. It helped with things like screws working loose, but didn't cure it. It did stop the Cha-Cha which is reason enough to leave it in place.

 

[klahanie]

^ that's what I use, bought from here (if you're not crossing the line)

https://www.bilsteincanada.com/advanced_search_result.php?search_in_description=1&keywords=24-186735&osCsid=2ru1uetaibf38sbvq1pkegrp21&Submit.x=19&Submit.y=7

If interested in these maybe check the cheaper 4600 also. For my rear app was told the valving is the same as the 5100, only diff is the chrome.

btw Vic were you in 4x or 2 ? ...

And, though I've read about the driving faster technique, are you sure you weren't creating at least as many vibrations, just at a different frequency. Just seems to me you'd be pounding the vehicle more. Expect every vehicle is a bit different and perhaps it works better with lighter vehicles, IDK. Whatever works ...

 

[ntsqd]

I think wheel-base has a bigger impact on the critical speed than does mass. Even at that, the difference is small.

The biggest difference is the amplitude reduction once the critical speed is surpassed, not the frequency change (you can't go fast enough to change the freq. by any order of magnitude).

My understanding of the 4600 series is that they use a smaller body tube than the 5100 series. I consider the 5100's to be the bare minimum oil volume. The 4600's would only be good for a truck that never leaves the pavement.

 

[Kolockum]

I think wheel-base has a bigger impact on the critical speed than does mass. Even at that, the difference is small.

I have noticed this when convoying with other vehicles of different lengths. Some of the guys are going through hell and others barely feel it. But I have NEVER seen toilet paper unravel!

 

[Vic Harder]

https://www.shockwarehouse.com/site/product.cfm/id/315309/name/Bilstein-B8-5100-Shock-Absorber-Chevrolet-GMC-Hummer-Front-24-186735

and

https://www.shockwarehouse.com/site/product.cfm/id/315311/name/Bilstein-B8-5100-Shock-Absorber-Chevrolet-GMC-Rear-24-186742

~$350 for all:
https://www.shockwarehouse.com/index.cfm?mode=results&selected_model=3824&selected_year=2006&type=T&selected_make=Chevrolet&model_name=Silverado+3500+4WD+(incl.+HD%2C+K3500+%26+K30)
That would get you started anyway.

Comment was made about a rubber bed mat. It was on Hole in the Rock where I realized that we really needed one. I was watching the camper do the Cha-Cha in the bed as we were driving. It helped with things like screws working loose, but didn't cure it. It did stop the Cha-Cha which is reason enough to leave it in place.

Oh, I already have new 5100’s all around.

 

[Mighty Dodge Ram]

I was told by a Bilstein rep that the difference between the 4600 and 5100 is length...the 4600 is for stock height, but a larger circumference on the 5100 also makes complete sense. Ran them on my Dodge and it was the very first change I made to the Chevy. Muy bueno.

As a side note: the same rep told me the correct pronunciation is BilStine but I can’t seem to change over from BilSteen. Oh well.

On another note: I’ve never driven Hole in the Rock but I have driven the road to the Racetrack several times. The last time I was there my new Leer canopy, held down by OEM clamps, began to walk itself backwards off the bed rails. We had to resecure it several times over the week. A couple of bolts have solved that issue. Washboard...hate it.

 

[Vic Harder]

^ that's what I use, bought from here (if you're not crossing the line)

https://www.bilsteincanada.com/advanced_search_result.php?search_in_description=1&keywords=24-186735&osCsid=2ru1uetaibf38sbvq1pkegrp21&Submit.x=19&Submit.y=7

If interested in these maybe check the cheaper 4600 also. For my rear app was told the valving is the same as the 5100, only diff is the chrome.

btw Vic were you in 4x or 2 ? ...

And, though I've read about the driving faster technique, are you sure you weren't creating at least as many vibrations, just at a different frequency. Just seems to me you'd be pounding the vehicle more. Expect every vehicle is a bit different and perhaps it works better with lighter vehicles, IDK. Whatever works ...

got the 5100's... no bed mat yet... we were mostly in 4x2 at speed

 

[Vic Harder]

I have noticed this when convoying with other vehicles of different lengths. Some of the guys are going through hell and others barely feel it. But I have NEVER seen toilet paper unravel!

The guys in jeeps were going much slower than me, and appeared to be getting tossed around a lot more too.

 

[Vic Harder]

I was told by a Bilstein rep that the difference between the 4600 and 5100 is length...the 4600 is for stock height, but a larger circumference on the 5100 also makes complete sense. Ran them on my Dodge and it was the very first change I made to the Chevy. Muy bueno.

As a side note: the same rep told me the correct pronunciation is BilStine but I can’t seem to change over from BilSteen. Oh well.

On another note: I’ve never driven Hole in the Rock but I have driven the road to the Racetrack several times. The last time I was there my new Leer canopy, held down by OEM clamps, began to walk itself backwards off the bed rails. We had to resecure it several times over the week. A couple of bolts have solved that issue. Washboard...hate it.

Stine makes sense.... given the German spelling/pronunciation rules.

regarding loosening clamps ... my Derringer Fast guns never loosened at all during this and the remainder of the 6000 km of the trip