Attaching DIY camper direct to Tacoma frame.

[johnbragg]

I'm planning a camper build, think mini, budget earthroamer, and wonder if anyone has experience mounting a camper "box" direct to the Tacoma frame?

 

[Tank5]

This camper is mounted on a tundra frame. The original builder built a steel platform/frame on the tundra frame then mounted the camper on the raised frame.

https://www.expeditionportal.com/forum/threads/tunook-build-has-new-life.115353/

 

[TernOverland]

I would build an isolation cradle for it. The Tacoma frame is very flexible, and that is best maintained. The bed area is pretty short, but a direct bolt is likely to have issues.

 

[javajoe79]

I would say it depends on how the camper is built. If it's designed to take the torsional stress that the frame will apply to it when you flex the suspension off road, then it would be fine to hard mount it but if not, you should mount it on a pivoting or sprung subframe. Check out the sticky thread in this section about pivoting frames and such.

 

[TernOverland]

There are two issues to consider. The most obvious is whether the camper can take the twisting. The other is whether you want the chassis flexibility limited by something rigid like a camper. Most trucks are built on ladder frames because it allows for flexibility. In most trucks that is a positive attribute. It actually becomes part of the action of the suspension and improves ride and articulation. Stiffening one section of the frame will increase stresses in other parts of it, which could lead to a broken frame. There have been examples of this discussed here. The first step is always to actually measure the flexibility of the chassis in question. Trucks vary a lot! The other question is whether this truck will see offroad use. It's obviously a much smaller issue with a truck that never gets flexed. There is no question that the camper and the frame will be working at odds with one another in a solid mount. The questions to answer are the extent of the flexing, and whether that amount matters in your application.

 

[jwiereng]

Are tacoma factory boxes hard mounted to the frame? I think the factory box on most pickup trucks are very stiff, or else caps, tonneau cover and caps would not sit nice.

I imagine a box mounted on rubber bushing would be sufficient for a camper body on a tacoma. Think about 4 runner, similar frame as the Taco, very stiff body, mounted on 6 or 8 rubber bushings.

 

[otis24]

Are tacoma factory boxes hard mounted to the frame? I think the factory box on most pickup trucks are very stiff, or else caps, tonneau cover and caps would not sit nice.

I imagine a box mounted on rubber bushing would be sufficient for a camper body on a tacoma. Think about 4 runner, similar frame as the Taco, very stiff body, mounted on 6 or 8 rubber bushings.

That's a good point about camper tops etc sitting nicely on the bed. I know when I'm fully flexed out off road the top of my camper doesn't move at all relative to the cab of my truck.

I've been thinking about building a pop top camper on my 1st Gen Tacoma. I'm planning on using the 6 bed mounts on bushings.

A few years ago I added a second gas tank from a 1990 Ford F150 where the spare tire used to be. Part of the tank mount are a pair of 1"x3"x.125" steel cross members welded into the frame. I also have 3-16" steel frame reinformance plates welded to the back part of the frame.

I think between the extra cross members, the frame plates and the bushings it should be good to go. I'm still going to measure the frame flex once I've taken the bed off the truck though.

 

[johnbragg]

Thanks to everyone for the replies. Definitely food for thought. I do think I need to isolate the camper from the frame somehow, it's just a question of how much. I don't anticipate doing any serious off roading, but would definitely be out on rough roads, dirt, etc.

 

[javajoe79]

When I started my camper build, it was meant for a pickup truck. I had it mounted to the factory bed mount spots using urethane body mounts from Energy.

 

[TernOverland]

Here are some actual measurements that might be helpful. We used a forklift to raise one rear tire until we gained maximum twist in the frame on 2007 access cab, w/6' bed. These measurements were taken with the bed removed. I have a CBI Moab bumper on the truck which stiffens the rear a good bit. These numbers would be higher without the bumper. The rear bed mounts were twisted 2.5 degrees relative to the front mounts. That translates to about 2" of deflection across the bed. The rear mounts were twisted about 3 degrees relative to the cab.

One other interesting note: We lifted the tire until we got another wheel to lift. I was expecting the front wheel on the same side to lift, especially because the travel in the front suspension is much less than the back. It turned out though that the front tires remained planted and the other rear wheel lifted. We were able to lift one tire about 16" before the other came off.

 

[jwiereng]

Tern -

Did you also do the test before the bed was removed? I wonder how the seemingly stiff composite bed accommodates the frame flex you observed.

 

[rruff]

When I started my camper build, it was meant for a pickup truck. I had it mounted to the factory bed mount spots using urethane body mounts from Energy.

That's exactly what I'm planning. Aluminum hat brackets bolted to the camper, and urethane body mounts. Do you have any details of your setup?

Are tacoma factory boxes hard mounted to the frame? I think the factory box on most pickup trucks are very stiff, or else caps, tonneau cover and caps would not sit nice.

Caps and toppers are also very flexible. So are beds.

There are two issues to consider. The most obvious is whether the camper can take the twisting. The other is whether you want the chassis flexibility limited by something rigid like a camper. Most trucks are built on ladder frames because it allows for flexibility. In most trucks that is a positive attribute. It actually becomes part of the action of the suspension and improves ride and articulation. Stiffening one section of the frame will increase stresses in other parts of it, which could lead to a broken frame. There have been examples of this discussed here. The first step is always to actually measure the flexibility of the chassis in question. Trucks vary a lot! The other question is whether this truck will see offroad use. It's obviously a much smaller issue with a truck that never gets flexed. There is no question that the camper and the frame will be working at odds with one another in a solid mount. The questions to answer are the extent of the flexing, and whether that amount matters in your application.

Tacomas and Tundras have a fairly flexy open C rear end. On my Tundra the front of the bed still has a very beefy closed C; it transitions to thinner C just after the front spring mount as I recall. They don't flex like big trucks, but they aren't as stiff as fully boxed frames. I think accommodating some flex is a good idea.

 

[Victorian]

I came across a newer Tacoma at last years Overland Expo West with a frame failure. Snapped right behind the driverscab. The owner had a custom camper build and installed by a well known outfitter. Needless to say the owner was not happy....
That made me wondering about those smaller trucks and camper bodies. It turns out that those smaller trucks are very popular for slide in campers in Europe (mostly Nissan and ford Rangers). Apparently most have a huge overhang past the rear axle. As a result the center of gravity will be totally out of wack and will put a lot of stress right behind the driver cab where most of the frame failures happen. Granded, those are not Tacomas, but those European trucks share basicly the same frame design. Up on further digging, I found a quote somewhere with the explanation of smaller pick up trucks being designed to carry loads like plywood, dirt, tools over short distances. Meaning that load would be low center of gravity and most likely not sticking out the back and therefore not streesing the frame at all. Now imagine a high center camper ,with a 3-4 overhang, driving off road for several weeks or months! This will put a tremendous amount of stress on the whole vehicle.
In other words, I would move up to a chassis that is designed to carry loads. Maybe a F-350 or even a 450 with straight frame rails?

 

[javajoe79]

That's exactly what I'm planning. Aluminum hat brackets bolted to the camper, and urethane body mounts. Do you have any details of your setup?
.

If you look here https://www.facebook.com/pg/CoffeyFabrication/photos/?tab=album&album_id=730697497040147 you can see the camper frame before I skinned it. I basically just used universal urethane body mounts from Energy at all the points where the bed bolted to the frame.

 

[DaveInDenver]

Are tacoma factory boxes hard mounted to the frame? I think the factory box on most pickup trucks are very stiff, or else caps, tonneau cover and caps would not sit nice.

I imagine a box mounted on rubber bushing would be sufficient for a camper body on a tacoma. Think about 4 runner, similar frame as the Taco, very stiff body, mounted on 6 or 8 rubber bushings.

Tacoma boxes are fiber-reinforced resin, so they are probably fairly stiff. The bolts are sleeved that go through the bed floor to the frame, so there's accommodation for movement. In fact there's enough movement that the bed will squeak when the material under the bolt heads wears down. This allows the box to burnish the tops of the supporting towers and it's annoying. I made UHMW pads to fit between the box and frame to get rid of it. The beds themselves are completely different in construction. The inner bed is a single molded cavity and the fenders are essentially just cosmetic skins. So the real strength is the composite inner bed, not the bed rails.

https://www.tacomaworld.com/threads...-flaw-explanation.388873/page-3#post-12873622

When I mounted my WilderNest on my Tacoma I anticipated the additional flex, at least compared to the truck I had it mounted on before, a 1991 Hilux/Pickup. Those had relatively rigid frames, fully boxed, and the beds themselves were double wall construction with welded seams. So they were also relatively rigid.

On the '91 the 'Nest was bolted directly through the bed frame rails with six 5/16" bolts and a layer of closed cell foam to seal against water and dust. That stuff squished flat instantly, its pretty cheap hardware store junk. But none-the-less it lived like that for at least 12 years only getting removed to replace the foam once in a while and clean the camper. The fiberglass developed a few stress cracks in the gel coat from the knocking around off road but it was manageable.

Fast forward to the Tacoma. I removed the top plastic plate to give a flat surface all around, then put a 1/4" layer of solid rubber on the bed rail and closed cell foam on top. Used four 10mm clamps to the cargo rail instead of through bolting. The camper is held fast but I am trying to let it have some give and isolate the vibration and movement. I've had the 'Nest on my Taco now for about 6 months and haven't done a tremendous amount of off road. White Rim, knocking around San Rafael.



I heard and subsequently noticed a sizable crack in the structural fiberglass around one of the ribs last week with the truck crossed up. So there's more flex in the Taco frame than I assumed. I'm rethinking how I mounted my 'Nest, not sure if I'm going to try isolating the camper more or reinforce the bed rail.

I don't want to build a subframe that ends up actually stiffening the frame but I think letting the camper float relative the bed rails is important. I'm trying to find a suitable rubber substitute for the 3 stacked washers in the mounting bolts (these were necessary to prevent pulling the mounting rail down). I think that ended up being too rigid and is still twisting the camper. It's not clamping down on the bed rails all that hard it's still focusing a lot of force on four stand-offs.