Pop Up Tent Trailer Repair, Lift Systems and Canvas
Written by RV Systems Lead, RV Systems and Electrical Lead, OCRV Center. Reviewed by Structural Repair Lead
In shortA tent trailer raises a light ABS roof on four steel cables and unfolds canvas over sliding bunk ends. The cable and pulley system plus the bunk end floors carry nearly all the failures.
What breaks on a pop up tent trailer?
On a folding tent trailer the lift cables, corner pulleys, ABS roof and bunk end floors account for most repairs, followed by canvas and vinyl windows. Rancho Santa Margarita owners bring Rockwood, Coleman and Jayco folding campers to our Yorba Linda shop for lift and structural work.
- Four cables and a winch raise the roof as one unit
- Bunk end floors slide out on steel glide bars
- The ABS roof is a stressed skin, not just a cover
- Canvas is a wear item and it is not a covered loss
- Lift system
- Four cable winch and pulleyGoshen or Barker style winch with corner pulleys and a single drum
- Roof
- One piece ABS or thin fiberglassStressed panel that carries the lift load through its corners
- Bunk ends
- Steel glide barsRigid bunk floor tray sliding out under a canvas cover
- Typical length
- 8 to 16 feet boxGVWR 1,900 to 3,500 lb on a single axle
- Mechanical rate
- $260 per hourLift systems and hardware; body and structural work at $210 per hour
Last verified
A folding tent trailer is a low box on a light single axle frame with an ABS roof that raises about four feet on four steel cables, canvas walls that unfold from the gap, and two bunk end trays that slide out on steel bars. Almost nothing about it resembles a hard walled camper, and the failure list is entirely its own.
The reason it matters to state that clearly is that these units are frequently priced and diagnosed as if they were small travel trailers. They are not. The lift system is the primary mechanical assembly on the vehicle, and it is what most owners actually need help with.
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Note
A pop up tent trailer raises an ABS roof on cables and unfolds canvas walls and canvas covered bunk ends. A hard side pop up raises rigid walls instead and has no canvas at all, which makes it a different repair entirely, and it has its own page.
The lift system is the vehicle's main mechanism
One winch drum, four cables, four corner pulleys and a set of lift arms raise the entire roof as a single plane. It has to stay a plane, because the canvas is sewn to fit a roof at a specific height and attitude. Any asymmetry in the system shows up immediately as a roof that rises crooked and a canvas wall that will not reach its fastening.
We service these as a system rather than as parts. Cables are replaced as a set of four, pulleys are checked for a grooved or seized sheave, the winch drum is inspected for a bent flange, and the lift arms are checked for free movement at every pivot. Replacing one frayed cable next to three of the same age is a repair with a very short life.
- Support the roof independently before releasing any tension
- Inspect each pulley sheave for grooving and free rotation
- Replace all four cables as a set with correct terminations
- Cycle and re-level the roof before refitting the canvas
The roof is a structural part, not a lid
A thermoformed ABS roof looks like a cover and behaves like a member. It receives cable load at four reinforced corners and it has to stay rigid enough to keep those corners in the same relationship to each other. Once ultraviolet has embrittled the material, the corners are the point where load and brittleness meet.
Adding a rooftop air conditioner to one of these is common and it changes the calculation. That static weight, plus the dynamic load of towing, plus a panel that is now decades old, is why we look hard at the corners on any unit that has had an air unit fitted. A crazed corner is not cosmetic on this vehicle.
Before you proceed
Crazing at an ABS roof corner on a folding camper is a lift system finding. It means the panel is losing the ability to hold cable load in that corner.
Bunk ends carry a person outside the trailer
A bunk end tray extends four feet beyond the body on steel glide bars and then holds a sleeping adult with nothing underneath it. The tray is lauan, and the only thing keeping water off it is canvas sealing against the roof edge and the box. When that seal goes, the water lands directly on the material that is doing the load carrying.
This is the failure we most often find on units that have been stored outside. An owner reports the bunk feels springy, which is generous language for a tray that has lost most of its strength. We probe from underneath with the tray extended, because from above a carpeted tray tells you nothing.
Canvas is consumable and nobody wants to hear it
The weather envelope on this vehicle is fabric. It gets folded, sometimes damp, and then sits compressed in Southern California heat for eight months. The canvas shrinks slightly, the clear vinyl windows sewn into it shrink and craze at a different rate, and eventually the wall will not reach the fasteners it was made to reach.
A canvas set is available for most units and fitting it is quick provided the box and roof are still square. Where fitting gets expensive is on a trailer whose bunk trays have been going in out of square for years, because then we are correcting geometry before the fabric can seat.
What folding camper work costs
Lift systems, hardware, canvas fitting and electrical work bill at $260 per hour. Body, roof, floor and structural work is $210 per hour with body supplies at $5 per body hour and paint supplies at $55 per paint hour. A written estimate is $150 and credits in full against an authorized repair.
These are the lowest value units we service, so the total loss conversation arrives fast. A full ABS roof replacement on an older folding camper can exceed what the trailer is worth, and we will tell you that at the estimate rather than at the invoice. Sometimes the right advice is to repair the lift and live with the roof.
Who owns folding campers
Families buying their first towable, and long term owners who have kept one for twenty years because it fits a garage and tows behind a mid size vehicle. Both groups are cost sensitive, and both are usually well served by us being blunt about which repairs are worth doing on a unit at this value.
The third group is overlanders using a small folding trailer as a base camp, which produces a different wear pattern: more dust in the glide bars and pulleys, more canvas abrasion, less rot. Rancho Santa Margarita owners can tow one of these here with almost any vehicle, which is part of the appeal.
How a pop up is built
| System | What it is |
|---|---|
| Wall system | Low rigid box of plywood or lauan over a light timber or aluminum frame with aluminum or filon exterior skin, topped by canvas or vinyl tent walls that unfold as the roof rises, with sewn in screened windows and zippered doors |
| Roof system | One piece thermoformed ABS or thin laminated fiberglass roof panel that is structural in the lift system, carrying cable load through reinforced corners, with a vent and sometimes an air conditioner mounted through it |
| Chassis | Light channel or tube frame with a single 1,900 to 3,500 lb rated axle on leaf springs, a bolt on A frame tongue with a 2 inch coupler, surge or electric brakes on the larger units only |
| Typical length | 8 to 16 feet |
| Typical GVWR | 1,900 to 3,500 lb |
What typically goes wrong on this vehicle
Lift cable fraying and snapping at a corner pulley
One winch drum pulls four cables that turn ninety degrees at a pulley in each corner post. Every raise and lower runs the cable across that same small radius, and grit collects in the pulley groove. The cable frays where it bends, not where it is anchored, and it is invisible inside the corner post until a strand lets go and the roof comes up crooked.
How we repair itCrazing and cracking of the ABS roof at the corners
The roof is a thermoformed panel that is also a structural member of the lift system, taking the cable load at four reinforced corners. Decades of Southern California ultraviolet make ABS brittle, and the corner is where load and embrittlement meet. Add an air conditioner and the panel is carrying a static load it was marginal for when new.
How we repair itSoft or collapsing bunk end floor
A bunk end is a rigid tray that slides out beyond the box and is covered by canvas that seals against the roof and the box edge. That seal is a wear item, and once it leaks the water lands directly on the tray, which is lauan. The tray then holds a sleeping adult four feet outside the body of the trailer with no support beneath it.
How we repair itCanvas mildew, shrinkage and split vinyl windows
Nothing else we service depends on fabric for its weather envelope. Canvas folds wet, sits folded in storage for months in Southern California heat, and the clear vinyl windows sewn into it shrink and craze at a different rate than the fabric. The result is a wall that no longer reaches its own fastening points.
How we repair itBunk end glide bars binding or scoring the box
The bunk trays run on steel bars through bushings in the box wall, and they are supposed to be lubricated and square. When one side has been forced closed against a fouled bar, the tray goes in out of square, the bar scores the bushing, and each subsequent cycle makes the alignment worse until the tray will not seal against the canvas at all.
How we repair itWhat common jobs run on this vehicle
Full lift cable and pulley replacement
$750 to $7,500
5 to 35 labor hours at $260 per hour, mechanical and electrical.
- Parts at $100 or less carry 100 percent markup. Parts over $100 carry 35 percent. Special order parts require a full non refundable deposit at order.
- Sales tax of 7.75 percent applies to parts and materials. Labor is not taxed.
- Cables are replaced as a set of four. Replacing one and leaving three of the same age produces a second visit within a season.
ABS roof panel repair or replacement
$1,200 to $12,000+
8 to 55 labor hours at $210 per hour, body and paint.
- Paint supplies at $55 per paint hour.
- Body supplies at $5 per body hour.
- Parts at $100 or less carry 100 percent markup. Parts over $100 carry 35 percent. Special order parts require a full non refundable deposit at order.
- Sales tax of 7.75 percent applies to parts and materials. Labor is not taxed.
- A 50 percent deposit is taken at authorization on any job over $2,000, with an additional 25 percent when parts arrive on any job over $10,000. Final balance is due at pickup.
Bunk end tray rebuild
$750 to $9,500+
6 to 40 labor hours at $210 per hour, body and paint.
- Parts at $100 or less carry 100 percent markup. Parts over $100 carry 35 percent. Special order parts require a full non refundable deposit at order.
- Sales tax of 7.75 percent applies to parts and materials. Labor is not taxed.
- A 50 percent deposit is taken at authorization on any job over $2,000, with an additional 25 percent when parts arrive on any job over $10,000. Final balance is due at pickup.
Canvas and vinyl window replacement
$400 to $2,500
2 to 10 labor hours at $260 per hour, mechanical and electrical.
- Parts at $100 or less carry 100 percent markup. Parts over $100 carry 35 percent. Special order parts require a full non refundable deposit at order.
- Sales tax of 7.75 percent applies to parts and materials. Labor is not taxed.
- The canvas set itself is the larger part of this number. Fitting is quick when the box and roof are still square.
Will it fit in the shop?
A folded tent trailer is the smallest unit in this building, generally under five feet tall closed and under sixteen feet long, so it goes anywhere and sits comfortably on a standard lift for frame, axle and bunk bar work. The practical requirement is vertical room to raise the roof and cycle the lift, which we have in the high bay. All of this happens in shop at Yorba Linda: there is no mobile service and no roadside call out, because a cable set has to be run with the roof supported.
Insurance considerations for this vehicle
- Canvas is a wear item and no carrier pays for it. Mildew, shrinkage and crazed vinyl windows are all excluded, and it is worth knowing that before a deductible is spent finding out.
- A snapped lift cable that drops the roof and cracks it is usually treated as mechanical failure rather than a covered peril, which puts the whole event on the owner. Cable replacement as preventive maintenance is far cheaper than the alternative.
- Values on folding campers are low, which means the total loss threshold arrives quickly. A cracked ABS roof on a twenty year old unit will often exceed the vehicle value, and we say so before writing a full scope.
Appendix: questions and answers
- What makes a pop up lift cable fray at the pulley?
- The cable turns ninety degrees over a small radius at each corner, and every raise and lower runs the same section of cable across that bend. Grit collects in the groove and cuts strands. It frays where it bends rather than where it is anchored, hidden inside the corner post until the roof rises crooked.
- Is a crazed corner on my folding camper roof serious?
- Yes. The ABS roof is part of the lift system and takes cable load at four reinforced corners, so it has to hold those corners in a fixed relationship. Ultraviolet embrittles the material exactly where that load concentrates. A crazed corner means the panel is losing its ability to carry the lift.
- My bunk end feels springy when someone lies on it. What is wrong?
- The tray has lost strength, almost certainly to water. That tray is lauan, it extends four feet beyond the trailer body with nothing underneath, and the only thing keeping water off it is the canvas seal at the roof edge. We probe from below with the tray extended, because carpet hides everything from above.
- Will insurance pay to replace shrunken canvas on a tent trailer?
- No. Canvas is a wear item and mildew, shrinkage and crazed vinyl windows are excluded on every policy we deal with. It folds damp, sits compressed through a hot storage season, and the fabric and the clear vinyl age at different rates. Plan for it as maintenance rather than a claim.
- One bunk tray goes in crooked and scrapes. Why?
- A glide bar has been fouled and the tray was forced closed against it. That scores the bushing in the box wall, so the tray enters slightly out of square, and every cycle after that worsens the alignment until the canvas can no longer seal against the tray edge. The bars and bushings need attention, not more force.
Open a file on this repair
Tell us the vehicle, what happened and whether a claim is open. We will tell you what the scope looks like and what it takes to get you back on the road.
Or call (949) 799-3387