Multi Slide Fifth Wheel Repair, Three to Five Rooms
Written by RV Systems Lead, RV Systems and Electrical Lead, OCRV Center. Reviewed by Structural Repair Lead
In shortPut four or five rooms in one sidewall pair and the trailer becomes mostly openings. Different rooms use different mechanisms, and the wall left between them is what fails.
What is different about a multi slide fifth wheel?
A multi slide fifth wheel carries three to five rooms, which leaves limited continuous sidewall between openings and mixes Schwintek, rack and pinion and hydraulic mechanisms on one trailer. Rancho Santa Margarita owners bring these to our Yorba Linda shop for room and structural work.
- Small rooms use Schwintek motors inside the room walls
- Large rooms use under floor rack and pinion or hydraulics
- Opposing openings leave a narrow band of shear wall
- Two rooms out on one side loads that floor edge together
- Mechanisms mixed
- Schwintek, Accu-Slide, Power GearIn wall motors on small rooms, under floor rails on large rooms, hydraulics on full walls
- Room count
- Three to fiveFrequently two on one side plus one or two opposite, and sometimes a rear room
- Continuous wall
- Very limitedThe wall band between and above openings is doing the shear work for the whole side
- Typical length
- 36 to 44 feetGVWR 15,000 to 20,000 lb
- Mechanical rate
- $260 per hourStructural work on rooms and openings at $210 per hour
Last verified
There is a point at which adding slide rooms stops being a floor plan decision and becomes a structural one. A trailer with one room has a sidewall with a hole in it. A trailer with five rooms has a series of openings joined by narrow bands of wall, and those bands are carrying all the shear the sides used to carry.
The second complication is that not all the rooms work the same way. A builder will use Schwintek in wall motors on a small wardrobe room and a rack and pinion or hydraulic system on a full wall room, on the same trailer, so one vehicle has two or three different mechanisms with different failure modes and different diagnostics.
At four rooms the sidewall is mostly openings
A laminated sidewall works as a stressed panel. It carries shear along its length, which is what keeps the box square as the frame moves underneath it. Cut one large opening in it and the surrounding structure carries the load around the hole. Cut four or five and the remaining continuous laminate can be narrow bands less than two feet wide.
Those bands are now doing the whole job. When they start to give, the crack is diagonal, running corner to corner between two openings, which is a shear signature rather than the rounded blister of a delamination failure. Recognising which of the two you are looking at changes the repair entirely.
Before you proceed
A diagonal crack running between the corners of two slide openings is shear, not delamination. Filling and refinishing it addresses the surface of a structural problem.
One trailer, two or three different mechanisms
Builders pick a mechanism per room rather than per trailer. A small wardrobe or dinette room gets a Schwintek pair with the motors inside the room's own walls. A large living room gets a rack and pinion system on rails under the floor, commonly BAL Accu-Slide or Power Gear. A full wall room may be hydraulic. All three can be on one trailer.
So the same reported symptom means three different things depending on which room it came from. A grinding noise on a Schwintek room is a track and synchronisation issue. On a rack and pinion room it is rail alignment or gear engagement. On a hydraulic room it is a cylinder or a valve. The diagnostic survey exists to get that right the first time.
- Schwintek: motors in the room walls, toothed vertical tracks
- Rack and pinion: under floor rails with a gear pack
- Hydraulic: cylinders and solenoids, usually a full wall room
- Each has its own failure mode and its own diagnosis
Two rooms out on the same side
An extended room cantilevers its own weight beyond the sidewall, and the floor edge carries that moment. With two rooms out along most of one side, the whole side is loaded simultaneously, and the floor edge between and beneath them has to resist it while the trailer is sitting on levelling jacks on whatever ground is available.
This is why we measure deflection at the floor edge with rooms in and out. Owners describe a floor that feels different at the campsite than at home, and they are correct: at home the rooms are usually in. Quantifying that difference tells us whether the floor edge needs reinforcement or whether the site was simply soft.
- Support the trailer on the frame at ride height, not on jacks
- Measure floor edge height with all rooms retracted
- Extend rooms one at a time and remeasure after each
- Compare the deflection pattern against the mechanism type
Five toppers on the weakest parts of the roof edge
Every room gets a topper awning to keep debris off the roof of the room, and every topper anchors to the roof edge directly above an opening. That is precisely where continuous roof structure is already reduced, because the room retracts under the roof line there.
A topper that has filled with water applies far more than its own weight to that anchor rail, and on a trailer with five of them there are five such loads on five weak points. When we re-anchor a topper rail we spread the load into structure rather than into the roof edge trim, and we check whether the topper tension is set to shed water rather than pool it.
When three rooms misbehave, look for one cause
Owners of these trailers frequently report a sequence: one room started sticking, then another, then a third over two seasons. That is almost never three coincidental mechanism failures. It is one structural change, usually in a shear band or at the floor edge, propagating into the openings around it.
So we survey all the rooms even when only one has been reported. It costs an hour of diagnostic time and it regularly changes the scope from a mechanism repair to a structural one, which is a much better conversation to have at estimate than after the second room has been rebuilt.
Rates and who tows five slide trailers
Mechanisms, hydraulics, toppers and electrical work bill at $260 per hour. Structural work on openings, shear bands and floor edges is $210 per hour with body supplies at $5 per body hour and paint supplies at $55 per paint hour. Diagnostic survey is $285 per hour with a one hour minimum, credited against an authorized repair.
Owners chose the floor plan, and the floor plan is genuinely excellent to live in. What they generally were not told is that the room count has a structural cost that shows up somewhere between year six and year ten. Being straight about that is more useful than repairing rooms one at a time.
How a multi slide is built
| System | What it is |
|---|---|
| Wall system | Laminated sidewalls over aluminum or steel tube framing with three to five slide openings distributed across both sides, additional posts and headers around each opening, and narrow bands of continuous laminate between openings doing the shear work |
| Roof system | One piece TPO or EPDM over composite decking with a slide topper awning over each room, and reduced continuous roof structure above the larger openings where the room retracts under the roof line |
| Chassis | Heavy steel frame with a raised upper deck at the pin and additional crossmembers under each large slide opening, tandem 6,000 to 8,000 lb axles, and under floor rails or hydraulic cylinders for the large rooms |
| Typical length | 36 to 44 feet |
| Typical GVWR | 15,000 to 20,000 lb |
What typically goes wrong on this vehicle
Schwintek in wall track stripping on a small room
A Schwintek pair drives the room through toothed tracks mounted in the room's own side walls, and it only works while both motors stay synchronised and both tracks stay parallel. On a trailer with several openings the sidewall is less rigid, so the opening racks slightly, one track binds and the motor strips teeth rather than stalling cleanly.
How we repair itShear cracking in the wall band between two openings
With four or five rooms the continuous laminate left between openings can be less than two feet wide, and that band is carrying the shear load for the whole side. It shows as a diagonal crack running between the corner of one opening and the corner of the next, which is a textbook shear pattern and not a delamination bubble.
How we repair itFloor edge deflection with two rooms extended on the same side
Each room cantilevers its weight out beyond the sidewall when extended. Two rooms out on one side apply that moment along most of that side simultaneously, and the floor edge between and under them is what resists it. Extend them both with the trailer levelled on soft ground and the deflection is measurable.
How we repair itMismatched mechanism diagnosis on a mixed system trailer
The same complaint means different things on different rooms of the same trailer. A grinding noise on a Schwintek room points at track and sync; the same noise on a rack and pinion room points at rail alignment and gear engagement; on a hydraulic room it points at a cylinder or a solenoid. Diagnosing the wrong system wastes the diagnostic hour.
How we repair itSlide topper awnings loading the roof edge above an opening
Every room gets a topper awning, and each topper is anchored to the roof edge directly above an opening where the continuous roof structure is already reduced. Five toppers means five anchor rails pulling on the weakest sections of the roof edge, and a topper that has filled with water applies a great deal more than its own weight.
How we repair itWhat common jobs run on this vehicle
Schwintek track and motor rebuild on one room
$500 to $8,500+
3 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.
- Track replacement without re-squaring the opening returns the same stripped teeth, because the bind is geometric.
Shear band repair between two slide openings
$1,500 to $20,000+
10 to 100 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.
Floor edge reinforcement under two same side rooms
$1,500 to $7,500
10 to 35 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.
Multi room diagnostic survey, all mechanisms
$285 to $2,500
1 to 9 labor hours at $285 per hour, diagnostics, scan and programming.
- Sales tax of 7.75 percent applies to parts and materials. Labor is not taxed.
- Credited in full against an authorized repair. On a trailer with three mechanism types this survey stops the wrong system being repaired.
Slide topper anchor rail re-anchoring
$500 to $3,500
3 to 14 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.
Will it fit in the shop?
This is the vehicle where slide clearance matters most in our building. A 44 foot trailer with four or five rooms needs every room extended and retracted repeatedly during diagnosis and setup, which means a bay with clearance on both sides rather than the paint booth. We stage these in an open bay for mechanism and structural work and only move them to the booth for refinish. The trailer sits supported on the frame at ride height, not on its levelling jacks, because jack geometry changes opening squareness.
Insurance considerations for this vehicle
- Multi slide trailers generate the largest supplements we write on towables, because a first estimate almost always prices one room and one mechanism. Where three rooms share a cause, the file has to establish the shared cause up front.
- Shear cracking between openings is fatigue and reads as wear. It is worth documenting even when it is not payable, because it is the finding that explains why three separate rooms have started misbehaving.
- Slide toppers that have filled with water and pulled a roof anchor are usually treated as a maintenance failure rather than a storm claim, unless a single storm event can be established.
Appendix: questions and answers
- What is the diagonal crack running between two of my slide openings?
- Shear. With four or five rooms the continuous laminate between openings can be under two feet wide, and that band carries the shear load for the whole side. A diagonal corner to corner crack is the signature of that band giving up, and it is a structural finding rather than a delamination bubble.
- Why does one room on my trailer use wall motors and another use floor rails?
- Builders select a mechanism per room, not per trailer. Small rooms get Schwintek pairs with motors inside the room walls. Large rooms get a rack and pinion system on under floor rails. Full wall rooms may be hydraulic. The same symptom therefore means three different things depending on which room reported it.
- Should the floor feel different with two rooms extended on one side?
- A little, and it is worth measuring. Each extended room cantilevers its weight past the sidewall, so two out along one side load the floor edge together. We measure floor edge height with rooms in, then after each room extends, which separates a floor edge that needs reinforcement from a campsite that was simply soft.
- Three of my rooms have started sticking over two seasons. Coincidence?
- Almost certainly not. Three mechanism failures in sequence usually means one structural change, in a shear band or at the floor edge, propagating into the openings around it. We survey every room even when one is reported, because it regularly changes the scope from mechanism work to structural work.
- Can slide toppers damage the roof edge on a five slide trailer?
- Yes, because each topper anchors directly above an opening where continuous roof structure is already reduced. A topper full of water applies far more than its own weight to that rail. We re-anchor into structure rather than roof edge trim and set the topper tension to shed water instead of pooling it.
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