New Piston Kit w/2 O- Rings

The New Piston Kit with 2 O-Rings from BERT TRANSMISSIONS is a precision internal transmission component engineered for builders and enthusiasts who demand reliability in high-performance automatic transmissions. This aluminum piston assembly addresses wear, leakage, and performance loss in transmission valve bodies where hydraulic pressure control is critical. Whether you're rebuilding a street machine, drag racing platform, or street rod, proper piston fit and sealing directly impact shift quality, line pressure consistency, and overall transmission longevity.

This kit features a 1-3/8 inch outer diameter aluminum piston body combined with two precision O-rings that create a sealed hydraulic chamber within the transmission valve body. The O-ring seals prevent cross-leakage between pressure galleries, maintaining separation between line pressure and exhaust ports—essential for proper shift timing and accumulator function. Aluminum construction offers a balance of strength and light weight while resisting corrosion in automatic transmission fluid environments. The compact 3.75 x 1.2 x 4.05 inch footprint and minimal 0.11 lb weight reflect the precision manufacturing required for internal transmission applications where clearances are measured in thousandths of an inch.

Transmission builders, independent shops, and dedicated gear-heads restoring or modifying BERT transmission-equipped vehicles will find this piston kit essential for complete rebuild or repair work. BERT TRANSMISSIONS components are known for supporting high-volume shifting and race-duty applications. Installation requires transmission disassembly and intimate knowledge of valve body layout; always reference your transmission service manual and consult a transmission specialist if uncertain. This is a single piston assembly—verify you need the correct quantity and that your transmission model uses this 1-3/8 inch diameter piston specification before ordering.