Cabover lifting while driving, anyone else?

[verynice]

On my trip this week to the Eastern Sierras my cabover was lifting at least 3" on the front from the winds/speeds. I had to use tie-downs from the tops of the hyd. cylinders to the dinette seat mounts to stop it from happening. My pump valve was closed and the only way this could have happened was the cylinder seals were not sealing properly??? I just replaced the O-rings and have no leaks and they lift fine. Anyone else have this problem? Any solutions other than tie-downs?

 

[Spike38]

Verynice,

Not a uncommon problem. Air seems to have enough pressure to lift the top of the camper. Getting passed by a 18 wheeler is a good cause. On my camper a 10' overhead it has a 4" x 3/8" bolt that goes thru to tie down the top half to the bottom half. This bolt goes thru at the left front of the lower half of the camper where the aluminum upright is located. The upright has a 90 degree angle attached with a hole for the bolt. On the upper section it has a sleeve that the bolt goes thru. I plan on installing the same set up on the right side when I replace my weather stripping.

Spike

 

[Spike38]

Verynice,

I posted a picture in the Alaskan picture gallery.

Good Luck
Spike 38

 

[Rusty]

Check the condition of your pirelli gaskets. Quite often when the pirelli ages it allows significant air in between the upper and lower sections, lifting the top....

 

[verynice]

Thanks, I couldn't find the picture in the gallery. I posted about 3 too many the other day... I replaced the seals with some Home Depot garage door seals so that just may have something to do with it also. I tried to get the pirelli but couldn't use a credit card to buy them from Alaskan (check only for purchases) and just seemed easier to grab some at the hardware store.

 

[wcj]

It has been an issue on all three Alaskan's I have owned. My 2004 has the bolt thru the drivers side, I added the same to the passenger side. Best solution I have seen. In a pinch, a ratchet strap over the top works.

 

[Rusty]

Good pirelli seals, replaced about every 5-7 years and keeping your hydraulic system closed tight while your traveling will help.

the pirellis are the big issue...underdraft through the space between the top and bottom pressurizes the interior and up she goes....it will also cut down (not eliminate) the dust buildup inside...especially on back roads in the summer. The pirelli material is laminated with fibers which allow it to retain its shape while following the contour of the camper. As it deteriorates, it loses the capability to change shape and hardens slightly...you know it's time to replace it when you can see the tiny cracks on the exterior side

 

[verynice]

Thanks. I talked to Brian at Alaskan and he said they are now installing exterior locks/pins to keep it down. Between having the cab/camper slider open for the dogs and the high winds I think I will just make an interior lockdown device for piece of mind.

 

[Mike S.]

I repaced my pirelli seals two years ago have not had a problem with lifting since. I watch it pretty close and if I seen it lift I would also drill the holes for the bolts but not until it's a problem again.

 

[Rusty]

do you have a slider installed at the front of the camper to access the camper from the cab for the doggies?

 

[verynice]

Yes, I'm pretty sure that's part of the "pressurizing" problem.

 

[Freebird]

I'm thinking that maybe an inflatable seal, that is inflated when either up or down, and air pressure is released for the transition between the two might be a worthwhile improvement. A tight seal would help with the air movement through the camper in the winter when the wind blows from either side. The good side of the air changing is you don't have to worry about carbon monoxide poisoning. The bad is you have to feed the furnace more propane than you would like to keep it comfortable inside. BTW, my Pirelli was replaced at the factory about 5 years ago.

Overall I really like my Alaskan camper. My wife and I snow birded to the SW this past winter (~2 1/2 mos.) in the camper, so I have some experience with one. (Camper is 2001 10' CO)
I am going to make some suggestions to Brian on some improvements that would be well worth incorporating... IMHO

I have the bolt by the driver's cab door that locks the front of the camper down. Works well for me, but my 91 Chevy 2500 4x4 PU is geared low, so we just mosey along about 60 mph typically. I might not even need the bolt at that speed

Freebird

 

[BluesideUp]

I had this issue driving my 11' back from KY to FL. The top was right over the drivers window so I was able to reach up and touch the top and bed. There was a flutter or vertical vibration of 1-2" at 60-70 which was max speed for me. I traveled with the valve in the open position as per previous owner and manual.
if anyone has a pic of a pin set up it would be appreciated

 

[verynice]

I did mine in the interior just on the inside of both cabover hydraulic rams. Mounting the hinge part of the hasp flat on the mattress side and the part that has the hole vertical next to the cylinder top mount, used this only a little nicer one- http://www.homedepot.com/p/Everbilt-3-1-2-in-Zinc-Plated-Adjustable-Staple-Safety-Hasp-15122/202033919#.Uno9QijPXao

It has worked great and leaves no chances for any leaks, the only downside is that you have to climb in and undo it before lifting. I have always driven with the valve "closed" as if it were in the open position it would lift even easier.