Tool Required VB-FIX Required

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Symptoms:
  • Burnt clutches
  • Clutch slippage
  • Converter concerns
  • Harsh shifts
  • High line pressure
  • Low cooler flow
  • Low line pressure
  • Low line rise in Reverse
  • No cooler flow
  • Overheated transmission
Cause:

Continuous oscillation of pressure regulator valve results in excess bore wear, causing erratic line pressure and/or restricting cooler/lube flow. Wear at the boost sleeve induces Reverse issues.

Correction:

Recover hydraulic control and renew line pressure performance by reconditioning the bore and installing Sonnax oversized pressure regulator and boost valve kit.

Tool Required VB-FIX Required

6L45, 6L50, 6L80, 6L90

Oversized Pressure Regulator & Boost Valve Kit

Part No.

104520-07K

Oversized Pressure Regulator & Boost Valve Kit
  • 104520-07k_combo

  • Oversized Pressure Regulator & Boost Valve Kit

  • 104520-07k_tools

Small_104520-07k_combo Small_104520-07k Small_104520-07k_tools

6L45, 6L50, 6L80, 6L90

Oversized Pressure Regulator & Boost Valve Kit

Part No. 104520-07K

  • Pressure Regulator Valve
  • Matching Outer Spring
  • Boost Valve
  • Boost Sleeve
  • Drill Bit
  • Checkballs (2) 1 Extra

Complaint:

  • Burnt clutches
  • Clutch slippage
  • Converter concerns
  • Harsh shifts
  • High line pressure
  • Low cooler flow
  • Low line pressure
  • Low line rise in Reverse
  • No cooler flow
  • Overheated transmission

Cause:

Continuous oscillation of pressure regulator valve results in excess bore wear, causing erratic line pressure and/or restricting cooler/lube flow. Wear at the boost sleeve induces Reverse issues.


Correction:

Recover hydraulic control and renew line pressure performance by reconditioning the bore and installing Sonnax oversized pressure regulator and boost valve kit.

GM 6L45, 6L50, 6L80 and 6L90 units may exhibit multiple line pressure and cooler/converter/lube flow problems due to excess wear in the pressure regulator bore. Deterioration at the balance spool end allows critical fluid loss, resulting in high line pressure, harsh shifts, and overheating due to reduced cooler/converter flow. Wear at the outboard spool robs converter feed pressure and lowers line pressure, resulting in soft shifts and burnt clutches. Wear at boost sleeve leads to loss of correct Reverse pressure.

Reconditioning the bore and installing Sonnax oversized pressure regulator and boost valve kit 104520-07K re-establishes the hydraulic integrity of these circuits for proper line pressure control in all ranges.

  • Oversized pressure regulator valve and matched spring restore OE function
  • Annular grooves help center valves in bore to reduce future side-load wear
  • Hardcoat anodized aluminum valves combat premature wear.
NOTE:

Pump must be removed to install this kit. Use of the VB-06 is required with the VB-FIX reaming fixture for this installation unless the stator support shaft is removed from the pump body.

Required Tools

Related Parts

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.

  • Test Locations

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Valve Body Layouts

Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.

Valve Body Layout GM 6L45, 6L50, 6L80, 6L90

Related Tech Articles

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GM 6L45-6L90 Vacuum Test Guide

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