C-Channel, subfloor, and outrigger question

[zen_stream]

Hi Airfourms!

I'm pretty deep into a renovation of a 68 ambassador. I have a question regarding the standard construction of Airstreams.

Are the bolts that connect the C-Channel to the subfloor supposed to secure to the outriggers? In other words, does the bolt go through the c-channel, subfloor, and then get secured to the frame at the edge of an outrigger? Or is the c-channel only typically connected to the subfloor and then the subfloor to the frame via all the elevator bolts?

The reason I'm asking is that when I took out my subfloor (minus what I left for support in the C-Channel), I noticed that the curbside and roadside of the c-channel are sitting on the outriggers differently. On the curbside, the subfloor extends flush to the edge of the outriggers, and it appears that the bolts are secured to the outriggers. On the roadside, the subfloor and c-channel extend an inch beyond the outriggers. The bolts seem to be only going through the subfloor in most places. In some places, there's a half hole drilled just on the edge of the outrigger but not entirely through it. Some of the bolts seem to sit in these holes as if they were meant to connect to the outrigger. Is this just evidence of a botched reno job (it does look like the trailer had previous work done)?

To note: I braced the shell using a good amount of 2*4s to keep the shell from falling and also to keep it from bowing out. I could understand if the shell bowed out an inch while I was taking out the subfloor, but I noticed this long before I had the majority of it out.

Thanks for the feedback!

[DremStremer]

The bolts go through the C channel and subfloor, then attach to the outriggers. That's how it is on my '70 Airstream. There are wood screws spaced in the channel as well that only screw into the subfloor. I noticed on my trailer that one sheet of subfloor comes up a bit short of the outriggers. This caused the C channel to be unsupported for some of it's width, but the bolts still attached to the outriggers through the subfloor. I'm pretty sure this was an error when the trailer was built. That might be the case with your trailer as well, or like you said, a botched reno. Good Luck.

[Bubba L]

The elevator bolts should go through the C-channel, subfloor and chassis members to aid in creating the semi monocoque structure. It’s not unusual for the subfloor to vary in relation to the end of the outriggers. On our 55 the street side was 3/4” past the end of the outrigger and the curb side was 1/4” over. I laid all the plywood on the chassis, popped a true centerline down the middle and centered it on the chassis. Then I cut the plywood. I triangulated off the axles to the center of the hitch ball in front and just took the center on the rear. That helps so when finished the trailer doesn’t “crab” down the road. Good luck

[zen_stream]

Originally Posted by Bubba L

I laid all the plywood on the chassis, popped a true centerline down the middle and centered it on the chassis. Then I cut the plywood. I triangulated off the axles to the center of the hitch ball in front and just took the center on the rear. That helps so when finished the trailer doesn’t “crab” down the road. Good luck

Thanks for the advice. What exactly do you mean by "crab" here? It doesn't sound good hah!

[Bubba L]

Originally Posted by zen_stream

Thanks for the advice. What exactly do you mean by "crab" here? It doesn't sound good hah!

You’ve seen 18wheelers going down the freeway and the trailer wasn’t “trailing” straight going down the road compared to what’s pulling it. If the axle on your trailer is not in sync with the hitch assembly, it won’t travel straight behind the TV. It’ll be kinda cockeyed. I’m sure someone else has a better explanation.

[JCWDCW]

Originally Posted by Bubba L

You’ve seen 18wheelers going down the freeway and the trailer wasn’t “trailing” straight going down the road compared to what’s pulling it. If the axle on your trailer is not in sync with the hitch assembly, it won’t travel straight behind the TV. It’ll be kinda cockeyed. I’m sure someone else has a better explanation.

Y
ou are right. The trailer wheels on a fifth wheel trailer are deliberately off a degree or so causing the trailer to "crab". This is done so the driver has a better view behind him or her in their driver side mirrors ...My belief anyways.
JCW

[guskmg]

Over the road semi truck owners are very particular about alignment because it effects their profit margin. However, if they are contract haulers with their own tractors they probably have no say in the trailer alignment issue, except maybe to complain.
guskmg