Line Press. Booster TH350

• Large Ratio Boost Assembly 
• Pressure Regulator Spring 

Sonnax hydraulic line pressure booster kits contain stronger pressure regulator springs and large ratio boost valves designed to work together to provide progressive pressure increases as driving conditions become more demanding.

Our pressure regulator springs are approximately 10% stronger than OE and more conservative in impact than other aftermarket kit springs. Large ratio boost valves provide higher pressure incrementally and when it is needed the most. The combination of these springs and valves in a Sonnax kit gives you the best of both worlds: a modest pressure increase at the low end, with a high-end pressure that is equal to or greater than that of other aftermarket kit springs.

• Achieve shorter shifts and increased torque capacity without creating low-speed harshness
• Improved band and clutch holding capacity for increased durability
• Progressive pressure increase as driving conditions become more demanding
• All the benefits of increased line pressure without overloading the pump at idle
• Simple and affordable drop-in solution with no special tools or reaming required

End-play shim TH400

Package Quantity: 10

Updated design tang style , 1997 & later, .010" Thick

Outer Dia.: 1.940"

It is often difficult to reduce front unit endplay on 400 or 4L80-E units with excessive spline wear. Normal component wear allows excess forward and direct drum travel. This travel or free-play reduces sealing ring life.

The 400 and 4L80-E are limited on the thickness of pump shim material that can be added. Excessive shimming at the pump will push the forward drum off the rings and result in a burned forward clutch. Sonnax offers a .010" thick shim, 34500-Z, that can be stacked under the sun gear bearing race.