Sunseeker Repair: Cabover Cracks and Cutaway Chassis Joints

The standard Sunseeker sits on a Ford E-450 cutaway. Some model years used a Chevrolet 4500. The MBS variant is built on a Mercedes Sprinter 3500 cab chassis and is a narrower, longer coach with different driving manners and a completely different parts network.

Identifying which you have is the first step in any estimate, because the cab is the fast half of the job. Ford and Chevrolet commercial dealers stock doors, fenders, glass and lamps. Mercedes parts arrive on their own schedule and cost more. None of that changes the coach body work behind the cab, which comes from the Forest River division.

The cabover overhangs the cab with no support beneath its forward edge, and the fiberglass is bonded to framing that flexes with every road input. Cracks start at the corners of the windshield header and travel outward. On a coach past eight or ten years this is the most common repair we write on the nameplate.

Proper repair grinds the crack to a taper, laminates from behind where the interior can be opened, rebuilds the front face with cloth and resin, then blocks and refinishes. Filler alone puts the crack back. If the framing behind has cracked or the bond has released, the area is opened until sound material is reached.

Where the coach body meets the cutaway cab, a flexible sealed joint absorbs the difference in movement between two structures. That sealant ages, hardens and cracks, usually at the top corners. Water then travels between the cab roof and the cabover floor and appears as a stain on the interior ceiling panel weeks later.

We inspect that joint on every one of these coaches that comes in for anything at all. Resealing it early is a short job. Replacing wet cabover decking, insulation and ceiling panels is a multi day interior repair, and by then the bunk mattress usually smells of it.

Most Sunseekers carry a one piece membrane over decking rather than a fiberglass roof. Membranes handle sun well and tear when something sharp lands on them, which around Santa Margarita Parkway and the canyon roads means branches. A tear does not announce itself: water runs under the membrane and finds a seam or a screw penetration.

Our repair maps the wet area with a meter, opens the membrane, replaces the affected decking, then patches with material chemically compatible with the original. TPO and EPDM patches are not interchangeable, and using the wrong one produces an adhesion failure at the next hot week.

Body, cap and roof work bills at $210 per hour. Appliance, slide and electrical work is $260. Diagnostics on an unidentified fault is $285 per hour with a one hour minimum, credited against an authorized repair. A written estimate is $150 on the same basis, and jobs over $2,000 take a 50 percent deposit.

OCRV Center is independent and has no dealer relationship with Forest River or the Sunseeker division. All work is performed in shop at Yorba Linda. Nothing here happens at a campsite or a storage lot, because laminate repair and membrane bonding both need controlled temperature and a clean surface.