Polaris 39-004 Bottom Housing Assembly – Replacement Lower Body Shell for Polaris 3900 Sport Pressure Pool Cleaner
The Polaris 39-004 is the replacement bottom housing (lower body shell) for the Polaris 3900 Sport pressure-side pool cleaner. This is the main lower housing that supports and protects the cleaner’s internal drive and water-management components and provides the mounting structure for the wheel and chassis assemblies.
Key Features
- Part Number: 39-004
- Part Type: Bottom housing / lower body shell
- Cleaner Compatibility: Polaris 3900 Sport (verify with your cleaner parts diagram)
- Function: Structural lower housing that holds internal assemblies and helps keep the cleaner aligned and sealed
- Use Case: Replace a cracked, broken, or worn bottom housing that causes misalignment, leaks, or poor drive performance
Common Reasons to Replace
- Housing is cracked or broken from impact, age, or stress
- Mounting points are stripped or damaged (wheel/axle/gearbox components won’t stay secured)
- Cleaner has abnormal dragging, misalignment, or unstable tracking due to chassis damage
- Internal components won’t seat correctly because the lower shell is warped or worn
Installation Notes
- Turn off the booster pump and remove the cleaner from the pool before servicing.
- This is a major structural component—transfer internal parts carefully and keep hardware organized during disassembly.
- While the cleaner is open, inspect related wear items (gearbox, wheel bearings, wheels/tires, and seals) to avoid repeat tear-downs.
- After reassembly, confirm wheels spin freely and the cleaner tracks smoothly with no rubbing or binding.
Related Products
- Search: Polaris 39-004
- Search: Polaris 3900 Sport Parts
- Search: Polaris 39-200 Gearbox Assembly
- Search: Polaris 39-300 Water Management System (WMS)
- Search: Polaris 39-005 Rear Housing
- Search: Polaris 39-401 Single-Side Wheel
- Search: Polaris 9-100-1108 Wheel Bearings
- Search: Polaris 39-500 Sweep Hose
- Search: Polaris Wall Fitting Screens
- Shop: Polaris
Installation & Maintenance Tips
- Before assuming a housing issue, check for worn bearings/wheels that can cause rubbing and stress the body.
- Rinse the cleaner after heavy debris events—grit and sand accelerate wear on moving parts and can lead to binding.
- Keep the wall fitting screen/filter clean to maintain strong flow; low flow can cause poor movement that looks like a mechanical problem.
- If your cleaner is a Polaris P39, confirm the correct bottom housing part number for that model before ordering.








