TCC Regulator Valve Kit for GM 4L80E 4L85E Sonnax 34994-01K

TCC Regulator Valve Kit for GM 4L80E and 4L85E automatic transmissions by Sonnax, part number 34994-01K.

Designed to help restore torque converter clutch hydraulic control when wear in the TCC regulator bore allows pressure loss. This repair addresses wear-related converter shudder, TCC application and release concerns, and related transmission codes.

Product Features:

• Hardcoat-anodized aluminum valve designed to resist premature wear.

• PTFE scarf-cut seal helps reduce hydraulic leakage at the critical bore wear area.

• Lengthened spool provides added stability and greater valve-to-bore contact.

• Annular grooves help center the valve and reduce side-load wear.

• Added chamfer supports improved TCC apply characteristics.

• Two selective springs provide original-equipment feel or firmer lockup suited to towing.

Kit Contents:

• One TCC regulator valve.

• One PTFE scarf-cut seal.

• One approximately .420-inch outside-diameter spring for original-equipment feel.

• One approximately .300-inch outside-diameter spring for firmer lockup.

Fitment:
Compatible with GM 4L80E and 4L85E automatic transmissions. Confirm the installed transmission and Sonnax part number 34994-01K before ordering. Do not rely on vehicle year, make, and model alone.

Installation Notes:
Valve body access and proper diagnosis are required. Follow the manufacturer’s instructions for seal installation and spring selection. A small bore-entry chamfer may be necessary if the bore interferes with the seal. Reuse the original solenoid and roll pin where serviceable; neither is included.

For related fluid service, consider Lubegard ATF products matched to the transmission’s required fluid specification. Sold separately.