Newbie With Conversion Questions

FlyingTruck

New Member
Joined
Nov 3, 2016
Messages
2
Location
Paola
Hi all,

I'm considering getting an old semi (Kenworth or Peterbilt) to do a conversion of some sort. I'm still figuring out the details of what exactly, and looking for some ideas and info to help guide me on this.

First off, a bit about our needs. We really don't have much for towing needs. We have a boat and a flatbed trailer. Both max out at around 7-8k lbs and use a standard 2" ball. We live on 11 acres and it wouldn't surprise me if we added a gooseneck trailer of some sort eventually. We also need a long-bed pickup bed. Really, these needs could all be filled with a standard 3/4 or 1-ton pickup like I've had many of before and spent a few hundred thousand miles towing with.

But, I also have a feeling we may end up with some larger towing needs, and I also have a desire to have a semi. We have a couple of full dresser Harleys and needs to transport cars, etc. semi-regularly. The flatbed trailer works for hauling cars fine and could be used to haul the motorcycles if I converted it.

I'm planning on something with a sleeper cab to start and would be interested in extending that conversion. To what degree is still up in question. We have 3 kids so it would be nice to have room for 5 normal seats, although I suppose with a pass-through that can be fudged around a bit. I'm open to ideas or thoughts from others with more experience.

In general, I'm thinking I'd like to graft a pickup bed (or build a custom bed of some sort) to the back 8-10 ft or so of a truck (probably convert to a single rear axle if it isn't already) and then build a box that would go between the existing sleeper and the bed to take up the extra space. Ideally this would have a pass-through of some sort, although it could also be used as just storage (perhaps bikes or the like, etc.).

I'm also debating whether to go with cabover or conventional. I like the cabover style and the wider cabin that goes with them, plus the shorter overall length you get. However a lot of people have pointed out to me there's a good reason why you don't see anyone driving cabovers anymore - bad ride and then also difficult to get into the back. I figure I need to check out a few to see what I really want.

I haven't owned a Class 7/8 truck before, but I've got plenty of time towing and have always done my own work. We do all our own projects so capability isn't an issue, but this is a new area to learn about.

I realize this is a fairly nebulous post. So to summarize I'm looking for a few things:

1) Thoughts on adding a pickup bed (or making some sort of bed type setup)
2) Any sort of run-down or basics page for construction of your own box, be it for just storage or a living area
3) Creating some sort of pass-through to an existing sleeper - is it even feasible to do?
4) Thoughts regarding cabover (would be a K100 or 352) vs. conventional (thinking W900 or 359)
5) Any other thoughts

Thanks!
 
w/ the exception of the GN trailer it sounds like you could make better use of a garage coach.

I don't think you'll find a CoE to be wider in the cab....in fact everyone I've ever been in was pretty crowded (w/ the dog box between the front seats)....and theyre noisy (think engine in the cab between you at your waste level).,...dont get me wrong theyre cool (again)....and if you have a LENGHT issue you could save a few feet w/out the engine out front.

do you actually NEED a pickup bed (enclosed sides & tailgate)? would a flat deck and drom box work?

BOB will be over here in a bit to direct you to another site for converting/singling tractors and registering them as motorhomes....until then have a look at what Greg at RV Haulers does to "retired" tractors - RVHaulers with Gregg
 
Hahahahaha, thanks for the cue Don. Maybe I won't tell him about that other site just to spite you. I immediately thought a garage coach would be the ticket for him too. FlyingTruck, great to have you on Truckconversion.net! Welcome to the loony bin. I know very little about a lot of things. My first suggestion is to put that building idea on the back burner for now. Search out everything remotely possibly acceptable to handle your needs first. There are lots of setups out there that might cover enough of what you want for much less money than building your own. I don't think there is going to be one coach that will do everything for anybody. The key is to figure out if there is one that covers enough to your liking. Even if you build it you're going to have to accept some compromise.
 
Appreciate the thoughts. A garage coach sounds like it might make sense.

Regarding the pickup bed, it's definitely the preference. I suppose you could look at this idea starting off with the idea of an oversized pickup. But then that will obviously leave quite a bit of room between the bed (assuming a standard 8' bed) and the sleeper, so the question would be what to do with that space. Really I could just buy a 1-ton dually and take care of today's needs just fine (and probably for some time to come). Part of the idea of doing this is a bucket list item.

Part of the plan with building is really wanting a pickup bed, and also looking at buying an older truck that needs some work and doing a bit of a customization/restoration. Compromise, of course will exist, but I have a lot of flexibility so that's fine.
 
not that any of us would try to talk you out of something - I'm curious...
why the pickup (type) bed?

given the price of a (new even slightly used) 350/3500 you could have a hell of a nice (used) garage coach.

Ive seen plenty of MDT's w/ pickup beds - and while i think theyre cool, they seem limiting and WAY over priced.

I believe that to get a (conventional) pickup bed to fit (and look) right on a class 8 tractor youre gonna need to widen & lengthen it (its gonna be expensive unless youre a good welder, body & painting guy).

Class 8's aren't convenient / daily drivers - so I'm not sure i get the advantage of a pick up bed....unless you want some unique show truck.
 
1) Thoughts on adding a pickup bed (or making some sort of bed type setup)
2) Any sort of run-down or basics page for construction of your own box, be it for just storage or a living area

(1) Yes, here are some thoughts.... I wanted to do some testing before really putting it out there, however We're putting a 5x8' "bed" sideways on the rear of a short box (13 foot box) class 8 motorhome. The "bed" will fold up flat against the rear of the coach (with lights in the back and bottom), then fold down flat when used for a patio deck or extra storage, or (we're still working this out but we think we can mount a gooseneck hitch in it). Normally, you tow with the 5th wheel / gooseneck over the wheels but with the weights involved the engineer says we'll be fine. It will tow a bit more like a bumper pull because of the swing involved in the overhang.

(2) Building the box. Often you'll see condensation on the outer skin at the location of the frame members of the box. This can be avoided by reducing the thermal bridging...heat transfer through the box walls. We've had good results with a 2x2 steel frame, (.090 if it needs to be structural, or .065 if less so), with 2" foam insulation in between the box frame members. We use 1/2" foam on the exterior, then 1/2 plywood over that, covered by aluminum. On the interior we use 1/2" foam, covered by 3/8 plywood covered by interior paneling. This results in a wall that is 4" thick, so you have to order your windows accordingly. It is much better insulated than most, heavier, and a has solid feel. The foam on both sides of the box frame reduces thermal bridging and although I don't have any engineering data, it seems to make a lot more difference than the R value of the foam itself. You also loose overall interior space in the width of the coach with the 4" walls.

You could cut down on those thicknesses by using 1 1/2 square tube, which would result in a 25% weight savings. I've found that using thinner plywood on the exterior results in a wavy side when installed over foam.

If you're not as concerned with insulation you can eliminate the foam on either side of the frame and go with thinner 1/4 or 1/8" luan on either side.

As others have said... It will cost more than you think. IMO, the only reasons to build it yourself are if you think it will be fun, or you can't buy what you really want. It will also help if you have a space and tools to do the build. It will be very expensive to pay someone else to build it for you.
 

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