I'm still pretty new to RV ownership and could really use some guidance here. My slideout has started rubbing against the exterior bathroom wall, and the coach is perfectly level.
The main thing I've noticed is that the gap at the bottom of the slide is much smaller now compared to the top - it used to be about 1½-2 inches at the bottom, but now it's barely anything. There's also about a ½ inch difference in height from one end of the slide to the other when I measure from the top.
I've independently jacked up both sides of the slide more than an inch each and checked the gap, but neither showed a difference. When I crawled underneath, I couldn't see where the slide might have moved laterally closer to the wall. The exterior stripes still line up. I also noticed the shower hasn't been used in 6 years or longer (I bought this coach used).
I'm wondering if this could be some kind of drooping issue? I've heard about things like rollers wearing out, but I honestly don't know what to look for or where to start troubleshooting. Should I be checking underneath the RV? Any advice on what might be causing this rubbing and smaller gap would be hugely appreciated!
Slideout rubbing wall with smaller bottom gap suggests drooping - worn lower rollers or adjustment needed. Inspect rollers, check mounting bolts, and look for floor damage underneath.
Based on your symptoms - the reduced bottom gap (from 1½"-2" to minimal), ½" drop from end to end, and rubbing against the bathroom wall despite your coach being level - you're dealing with a sagging slide floor structure rather than a wall movement issue. The fact that jacking up both sides independently didn't change the bottom gap confirms this. Your slide's floor joists or support structure has likely weakened over time, causing the entire slide floor to bow downward. Since the stripes line up and you found no lateral movement underneath, the wall hasn't shifted - the slide itself is drooping.
Slide floor sagging commonly occurs due to deteriorated floor joists, failed subflooring, or compromised slide box structure. In your case, with an unused shower for 6+ years, moisture intrusion is a prime suspect. Even without active use, seals can fail and allow water penetration, leading to wood rot in the floor joists or subflooring.
The slide mechanism itself appears functional since it operates normally and maintains proper lateral positioning. However, the structural support underneath has weakened. This is common in bathroom slides due to plumbing penetrations creating potential leak points. Temperature cycling over years can also cause fasteners to loosen and wood components to shrink, creating gaps where moisture can enter.
Another possibility is that the slide's mounting points to the main frame have shifted or the attachment hardware has loosened. This would allow the entire slide assembly to tilt slightly, creating the symptoms you're observing. The weight distribution changes as components age, and original factory tolerances may no longer be adequate.
Start by thoroughly documenting the current condition with photos from multiple angles, including close-ups of the gap variations around the entire slide perimeter. Measure and record the exact gap dimensions at 12-inch intervals around the slide opening with the slide fully extended for operational measurements, and also take measurements with slide retracted to establish frame reference points. This baseline will help track any changes and guide your repair approach.
Remove all items from the slide including furniture, fixtures, and flooring materials to reduce weight and provide access. You'll need to disconnect any plumbing, electrical, or gas connections that might interfere with your inspection. For gas lines, turn off LP gas at the tank and properly cap any disconnected gas lines. Turn off water pump and disconnect shore power before starting. Drain water lines completely, use proper pipe caps or plugs for any opened water lines, add RV antifreeze to P-traps to prevent freezing, and properly isolate electrical circuits at the breaker panel with appropriate wire nuts or junction boxes. Rent or borrow hydraulic jacks with appropriate capacity - determine the required capacity based on your specific slide size and estimated weight, consulting your RV dealer or manufacturer specifications for guidance.
SAFETY WARNING: Never work underneath an RV slide without proper safety precautions. Use appropriate jack placement on structurally sound mounting points, always use jack stands as backup support, and wear safety glasses and work gloves. Ensure the RV is on level ground and wheel chocks are in place before beginning work.
Gather moisture detection tools like a moisture meter or probe to check for water damage in the floor structure. You'll also need basic hand tools, flashlights or work lights for under-coach inspection, and safety equipment including jack stands and blocking materials. Consider having replacement lumber and hardware on hand if you discover structural damage during your investigation.
Begin by accessing the slide's underside to inspect the floor structure thoroughly. Look for darkened, soft, or deteriorated wood in the floor joists and subflooring. Pay special attention to areas around plumbing penetrations and the shower drain connection. Use a moisture meter to identify wet or previously wet areas that may have compromised structural integrity.
If you find rotted or damaged floor joists, you'll need to sister new lumber alongside the damaged sections or replace them entirely. This requires carefully supporting the slide floor load while making repairs. Position hydraulic jacks at strong points under the slide frame, not the damaged floor structure. Cut out any deteriorated subflooring and replace with exterior-grade plywood (typically 5/8" for 16" on-center joists or 3/4" for 24" on-center joists - verify correct specifications with your dealer).
Check all mounting hardware connecting the slide assembly to the main coach frame. Tighten any loose bolts to manufacturer specifications (if manuals are unavailable, consult your RV dealer for proper torque values) and replace any that show signs of elongation or corrosion with the correct parts for your model. If the mounting points themselves have shifted, you may need to drill new holes and use larger fasteners or backing plates to distribute loads properly.
After structural repairs, check slide alignment using manufacturer specifications and adjust slide mechanism as needed before testing operation. Verify that your slide operates smoothly and the gap measurements have returned to normal specifications. The bottom gap should be consistent around the perimeter and match your original 1½"-2" measurement. Test the slide through several complete cycles to ensure the repair hasn't created binding or interference issues.
Call a professional RV service center if your inspection reveals extensive structural damage requiring major carpentry work or welding repairs to the slide frame. Most DIYers can handle minor joist sistering or subflooring replacement, but major frame modifications require specialized knowledge and equipment. If you're uncomfortable working under a raised slide or lack proper jacking equipment, professional help is essential for safety.
Additionally, seek professional assistance if your slide mechanism itself shows signs of wear or damage that became apparent during your structural inspection. Slide motor, gear, or track problems require specialized tools and knowledge to repair properly. Some manufacturers also require professional installation of structural repairs to maintain warranty coverage on related components.
Consider professional help if you discover that the coach's main frame has shifted or if multiple slides are showing similar symptoms. This could indicate a more serious structural issue with the entire coach that requires comprehensive evaluation and repair beyond typical DIY capabilities.
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