8HP45

Tool Required

Symptoms:

• Harsh shifts
• Soft shifts
• Erratic line pressure
• High line pressure
• Burnt clutches
• Restricted converter/lube flow
• Broken parts due to excessive line pressure

Cause:
Excess pressure regulator valve and sleeve wear allows fluid loss and/or causes valve hang-up, preventing normal line pressure control.

Correction:
Restore appropriate line pressure in all ranges by reconditioning the bore and installing wear-resistant Sonnax oversized pressure regulator valve kit.

Vehicles equipped with Chrysler 845RE and ZF8HP45, ZF8HP55 and ZF8HP70 transmissions often develop erratic or high line pressure due to excessive wear in the OE pressure regulator valve bore and/or sleeve. This wear allows critical oil loss, preventing proper line pressure regulation. Without correct balance oil pressure, the PR valve will be out of its desired position, resulting in line pressure instability and possibly restricting cooler and lube flow. A deteriorated bore can cause lowered line pressure, resulting in soft shifting and burnt clutches. Reconditioning the bore and installing the Sonnax oversized pressure regulator valve kit renews pressure regulator action for revived line pressure control in all ranges.

• Hardcoat anodized aluminum valve combats premature wear
• Annular grooves help center valve in bore to reduce side-load wear

Contents:

• Valve
• Sleeve

SONNAX Installation Instructions