47RE/48RE Billet 2nd Gear Accumulator Piston

Features:

• Compatible with 47RE and 48RE transmissions
• Billet aluminum construction for superior strength
• Double O-ring seals prevent fluid leaks
• Replaces failure-prone factory cast piston
• Improves second gear shift performance
• Installs without removing the transmission
• Located under valve body between servos
• Increases transmission durability and reliability
• Reduces wear from leaky steel delivery rings

2nd Gear Accumulator Piston for 5.9L Cummins

If you're trying to get more life and smoother performance out of your 47RE or 48RE transmission, the ATS Billet 2nd Gear Accumulator Piston is a smart and effective upgrade—especially if you're running a 1996–2007 Dodge Ram with the 5.9L Cummins. These transmissions are known workhorses, but the stock cast 2nd gear accumulator piston has a reputation for causing issues as it wears out, particularly when it comes to fluid leaks and inconsistent shifts. What ATS has done with this billet version is fix one of the more overlooked failure points in the valve body area. Instead of the factory-style cast piston that relies on fragile steel delivery rings, this CNC-machined billet aluminum unit uses dual O-ring seals to ensure a tight, leak-free fit. That means smoother, more reliable second gear engagement and less internal wear over time—especially important if you’re towing, running performance tuning, or just want your transmission to last.

High-Performance Design

The design fits right where the factory piece sits—under the valve body, between the front and rear servos—and it drops in without needing to remove the transmission. That’s a huge bonus if you’re doing the work in your driveway or already inside the valve body for other upgrades like a shift kit or servo replacement. It’s one of those upgrades that doesn't take much time but pays off in long-term reliability and performance. So whether you're chasing firmer shifts or just want to eliminate one more weak point in your 47RE or 48RE, this ATS billet 2nd gear accumulator piston is a small part that brings real peace of mind.

Fits: 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Dodge Ram 5.9L Cummins

Application Note: Located Underneath the Valve Body