We ended our last update by finishing the restoration of a slide-in camper for our 2001 Ford F-250 pickup's truck bed. With just a few thousand dollars and hundreds of hours of nasty, sweaty work replacing rotten wood, we’d basically built the GRM version of those fancy motorhomes you see in the owner/driver lot of the world’s premier endurance races. Trackside villas ain’t got nothing on the majestic Mountain Star!
But there were still more pieces of the puzzle: Now that our toothpick-mobile home was back in one piece, we needed to be able to safely cart it to the track, not to mention drag our race car along with us, too.
We retrieved the Mountain Star with just four ratchet straps, careful driving, and high liability limits on our insurance. And while that approach worked, the camper arrived home six inches further away from the truck than it started. Did we notice a 12-foot-tall, 2000-pound box suddenly moving six inches while we were driving down the highway? We’ll answer that question as soon as we stop shaking and manage to pry our ghost-white knuckles from the truck’s steering wheel.
Fortunately this isn’t new territory, and the aftermarket has a few options for those looking to keep their campers attached to their trucks. There are basically two good choices to strap a camper into a modern pickup truck: frame-mounted tie-down points from Torklift, and bed-mounted, tie-down points from HappiJac. Lighter campers can also be held down with special adapters for the truck’s stake pockets, but our Mountain Star was too big for that to be a reasonable option.
What’s the difference? Simple: The frame-mounted tie-downs mount to (you guessed it) the frame, while the bed-mounted tie-downs mount to sheet metal found at the front of the bed and rear bumper. Either option hooks to the camper with spring-loaded turnbuckles, which keep it in place without harming its delicate wooden structure. We weighed the pros and cons of both options, settling on the more expensive (but stronger) frame-mounted tie-downs for our camper. We could have saved some money by choosing HappiJac's system, but figured it wasn’t a bad idea to remove the compliance of the OEM rubber truck bed mounts from the tie-down system. Plus, frames are much stronger than sheet metal, and mounting to the frame wouldn’t require drilling any holes, either.
And even better: We’d save a boatload of money, since we could just copy the Torklift frame brackets with our own steel and welder. Torklift charges a pretty penny for their products–figure more than $700 for a set of four frame brackets, and that’s before you buy any turnbuckles–and we weren’t eager to spend money if we didn’t have to. Then we printed out some photos and looked at the truck, and decided to compromise our principles just a bit. We spent $367 on a pair of Torklift front frame mounts for our truck. They promised to be custom fit, and bolt to the frame and the bed perfectly with no drilling required and all hardware included. In just 40 minutes, the pitch went, we’d have custom-fit tie-down points that easily removed with one pin when we weren’t using the camper. We simply didn’t have time to do as good of a job building these fairly intricate parts. And, as promised, they really did install in a few minutes with practically zero effort.
But c’mon, we’re not suckers! Torklift wanted nearly as much money for the rear tie-downs, and they aren’t intricate brackets that interact with the truck at three separate points. They’re just sticks of steel that clamp onto the trailer hitch, and we weren’t about to spend $300 on them. We ordered the same size and wall thickness tubing to copy the front tie-downs and keep the removable inserts interchangable, then built our own brackets for the rear of the truck.
With our frame mounts finished, it was time for turnbuckles. For our first trip we simply used the HappiJac turnbuckles that the seller included with the camper, but it took an eternity to install and remove them with a pair of wrenches. We needed something with a quick release, so we opened up the Torklift catalog. They absolutely sell spring-loaded, quick-release turnbuckles. And they absolutely charge nearly $800 for a set of them. Yeah, uh, no. Instead we spent $300 on a set of HappiJac quick-release turnbuckles, then sold what we’d been using on eBay for $100. We’d now spent more than $500 on properly attaching our camper to our truck, but we told ourselves it was a fraction of what most people would have spent and moved on before we felt too bad about our financial choices.
The Mountain Star was firmly attached to the truck, but getting our living quarters to the track wouldn’t help if we couldn’t also take our race car there. Which begs the question: Can you tow a trailer with a slide-in truck camper? The answer is yes, but it’s not as easy as hitching up and hitting the road. There are two main challenges: Physically attaching the trailer, and making sure you don’t overload the truck in the process.
We’ll start with the math question: Would towing a trailer overload our truck? Every vehicle has a weight it’s rated to carry, and while the reality is you’ll probably be fine if you exceed it, it’s not a great idea to go into this planning on overloading your truck. We ruled out a bunch of campers because they were just plain too heavy, and wouldn’t leave us enough excess carrying capacity to tow our car. What adds weight to a camper? Everything, but slide-outs are one of the worst offenders. Extra space is nice, but so is staying within your truck’s limits, and slide-outs are extremely heavy.
Our truck’s Gross Vehicle Weight Rating (GVWR) is 8800 pounds, while its curb weight is 5708 pounds. That means we have 3092 pounds of capacity for everything in/on the truck, including the tongue weight of any trailers we’re towing. What about the weight of our front trailer hitch, helper springs and tie-downs? We’ll call that a wash, since we also leave our 60-pound tailgate at home when the camper’s in the bed. While 3092 pounds may sound like a lot, it goes quickly when you start subtracting goodies. We weigh 150 pounds, and usually bring a friend to events. There’s 300 pounds gone. We’ll also bring about 50 pounds of camera gear, clothes, driving gear, etc. Our total is down to 2742 pounds, and we haven’t even added any actual “cargo” yet. So we will-our camper's factory curb weight is 1910 pounds with full water and propane tanks, but that’s without dishes, drinks or any of our other camping gear. We knew this, and made a conscious effort to lighten the camper as we rebuilt it. It’s now missing a row of cabinets, a footlocker, and a closet in order to shave weight and keep our rig legal (we also think it lives better in this more-open configuration). We chose a lightweight mattress for its bunk, too, and always kept weight in mind when stocking it with the rest of our gear.
The bottom line is that the Mountain Star takes up the majority of our remaining weight capacity, and the 500-pound tongue weight of our enclosed trailer puts us right on the edge. This compromise is just a fact of life when trying to use a single-rear-wheel, 3/4-ton pickup truck to do what we’re doing, and to be honest, we wouldn’t do this without a well-maintained truck, helper springs in the rear, and brand new, properly rated tires that we check at every fuel stop.
We’d figured out we had the capacity to safely tow a trailer, if only barely, so now we needed to attach it. This posed a bit of a problem: Our trailer hitch was on the back of the truck, and the back of the truck was two feet in front of the rear of our camper. We thought about just hooking up things anyway, but the wastewater tanks immediately above the hitch ball gave us second thoughts about what would happen if our aim was off when backing up, or if we tackled a driveway slightly steeper than expected. We needed to extend our hitch backwards in order to safely attach and tow a trailer.
Our F-250 still sported the factory receiver hitch, which had a 2-inch opening and was only rated for 5000 pounds of weight-carrying trailer towing. Hitch extensions lower capacity dramatically, as they act as giant levers that pry on the hitch and its attachment points. So, in order to use one, we needed a much, much stronger hitch. 
So we opened the Torklift catalog. They make fancy hitches designed for towing trailers with slide-in campers like ours. Each features a pair of normal receivers stacked one on top of the other, which mate with Torklift’s hitch extensions to offer eye-popping towing capacities even at lengths as long as five feet. One problem: Their prices are also eye-popping, as it would have cost more than $1200 for a hitch and two-foot extension.
There had to be another way, so we went back to the drawing board. After some more research, we realized that if we upgraded to a sturdy hitch with a 2.5-inch receiver like those found on modern trucks, we’d be able to use a simple extension to be able to safely tow 8000 pounds, with 800 pounds of tongue weight two feet behind our truck. We ordered a $232 Draw-Tite hitch rated for 18,000 poundss and a 24-inch extension from etrailer.com. Total price? $408, solving our problem for a third of Torklift’s price. Everything installed in about an hour, simply replacing the OEM hitch, which we then sold on Marketplace for $20. We made some new safety chains and a trailer wiring harness extension/splitter, then loaded everything up for its maiden voyage.
What’s the best way to put a completely untested combination through its paces? A 1200-mile roadtrip, of course! We needed to pick up a Triumph Spitfire in Richmond, Virginia, so we strapped the camper in place, hitched up our aluminum open trailer, and hit the road. And, shockingly, the rig drove perfectly. We couldn’t even tell the trailer was back there, and even with the car loaded, we cruised down the highway at 75mph with no issues. Backing up was a breeze, too, since even though this thing looks like a giant RV, it’s still just as maneuverable as a normal pickup truck.
Trial run a success, we decided to up the stakes and go for a real test: A 1000-mile trip to visit Very Cool Parts, home of our crew chief and a LFX-swapped Miata we needed to work on. Instead of a little British car on an open trailer, this time we’d be taking along our LS1-swapped Nissan 350Z in a 20-foot enclosed trailer. Once again, we loaded the camper and hitched up the trailer. This time around, though, we installed the weight distributing hitch and sway control hardware originally purchased for our Super Van project. This fancy hitch transfers weight from the rear axle to the front axle of the truck, and also has a friction brake to damp sway in the event of a blown tire or a gust of wind. After spending an hour adjusting everything and taking a test run around the neighborhood, we hit the highway.
And, stunningly, it towed beautifully. We set the cruise at 75mph, turned the radio up, and settled in for one of the most relaxing tows we’ve had. This rig just plain soaks up the miles, and stays stable even when passing trucks and transitioning between uneven pavement. Not that there isn’t an expected lack of body control–we’ll definitely be adding fresh shocks and a rear anti-roll bar before we do this again, but those won’t be simple fixes: They’ll be an improvement. Gas mileage? Yeah, it’s horrible. Figure on getting about 8-9 mpg from this rig at 75 mph. But given the easier maintenance (and much lower cost of entry) compared to a diesel truck, poor fuel economy is a tradeoff we can live with. 
So, what’s our verdict after spending an extra $1000 on tie-downs and trailer hitches? As we merged onto the highway leaving Very Cool Parts, we declared the mission a success. With about an $8000 total investment, we’d built a rig that’s a practical pickup truck during the week, then transforms into an RV that can comfortably tow our car to the track and act as home base and living quarters for the race weekend. We’ll continue optimizing the Super Truck as time goes on, but we’re ready to call this basic formula a success.
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Gooseneck: I drove someone else's truck/race trailer once...I'll never go back to a bumper pull.
Currently tenting on the trailer after unloading the car which stays high and dry. Plus canopy along the trailer for shade/dry area.
A nice budget combo would be 40ft low deck gooseneck + slide in camper mounted on trailer (box side areas replaced with tool boxes and storage) + race car on the back. Neighbor does this with a mud truck.
We did something similar to tow a 3,000lb boat on a single axle trailer with a 13-1/2' slide in camper on an '87 GMC K2500.
Since it was about 25 years ago we had to improvise, and used solid bar stock for the extension. Due to the receiver hitch angle we had to notch, bend, and weld the extension to get the right height. We also added chains from the extension to the step bumper corners to reduce sway along with extensions for the safety chains to maintain the connection to the tow vehicle frame,
It towed nicely and never had any issues, but did get some funny looks at the boat ramp.
8 to 9mpg at 75mph is nothing to be sad about, that's quite excellent for a combination this size.
newrider3 said:8 to 9mpg at 75mph is nothing to be sad about, that's quite excellent for a combination this size.
considering that bricks probably have a better drag coefficent?
We did this for YEARS. We always traveled in a slide-in and towed the boat. Dad fabbed up a sliding bumper and it was brilliant. It had a fold down step for the door.
Basically he bolted two sections of heavy channel on the frame and made a bumper with two longer channels on it. When the camper was off, you slid the bumper in and put a pin in it. With the camper on, you pulled the pin and slid the bumper out. It was plenty heavy duty for our 3000-lb boat, but would have needed a bit more heft for a car hauler.
I ran into this problem when towing. Short bed truck with an 8' camper meant the tailgate was always down. My solution was to build my new trailer (not pictured) with a long tongue and fold away jack. Worked great!
Pretty obvious Torklift isn't a GRM advertiser... LOL
Having run their products for close to 30k miles of camper + 24ft enclosed race trailer I can confirm their stuff is expensive, but worth it. No one else makes extensions that can handle more than ~800lbs tongue weight (with WD) which is right at the limit for a lot of enclosed trailer setups at 10%. Especially if you need to go longer than 24". I can go up to 1500lbs tongue weight (with WD) on my Torklift 28" extension, which provides a lot more overhead.
Slide-in + trailer is definitely one of the more versatile setups... truck - truck/trailer - truck/camper - truck/camper/trailer. Covers all the bases without having to maintain/register/insure a separate RV. It's not without drawbacks, but checks a lot of boxes.
BTW, I'd hit a truck scale and check your axle weights if you haven't already... I've yet to see a camper that isn't significantly heavier than its "brochure" weight. 
My FIL goes to tractor shows and he popped a slide in on the top portion of a gooseneck so he can use the rest of the trailer for his tractors. It's a pretty sweet setup.
I like this idea just because it's so ambitious. It's well past the line where you actually have to do it correctly or its automatically a deathtrap. Seems like the right amount of effort went into the assembly AND the testing, and now it tows well. I don't know that i'd ever try to replicate this type of arrangement for myself (rather just be towing with a small RV because i don't have much actual need for a large truck), but to see it done well still makes me smile.
Ok, it's time for the old guy to question 75mph towing something at or near weight capacity? With yesteryear braking technology and the same for handling. The idea is to avoid a crash, any idea how far you travel in distance at 75 MPH and then add the braking distance plus reaction time?
I would be very interested if you or your staff has ever tested a panic stop of your "rig" at any speed.
Any good RV magazine will tell rv drivers to not drive 75
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