Tool Required VB-FIX Required

Printpartsummary
Symptoms:
  • Engine surge at idle
  • Low cooler flow
Cause:

Low converter release pressure at idle.

Correction:

This Sonnax kit allows the rebuilder to restore correct clearances for proper hydraulic control.

Tool Required VB-FIX Required

4L80-E, 4L85-E

Oversized Line-to-Lube Pressure Regulator & Boost Valve Kit

Part No.

34200-36K

Oversized Line-to-Lube  Pressure Regulator  & Boost Valve Kit
  • 34200-36k_combo

  • Oversized Line-to-Lube  Pressure Regulator  & Boost Valve Kit

Small_34200-36k_combo Small_34200-36k

4L80-E, 4L85-E

Oversized Line-to-Lube Pressure Regulator & Boost Valve Kit

Part No. 34200-36K

  • End Plug
  • Pressure Regulator Valve
  • Pressure Regulator Spring
  • Boost Valve
  • Boost Sleeve
  • Pressure Regulator Valve
  • Boost Valve
  • Boost Sleeve
  • Spring
  • End Plug

Fits ‘99-later

Complaint:

  • Engine surge at idle
  • Low cooler flow

Cause:

Low converter release pressure at idle.


Correction:

This Sonnax kit allows the rebuilder to restore correct clearances for proper hydraulic control.

GM 4L80-E and 4L85-E pressure regulator valve design prevents adequate cooler flow at low RPM and high pressure/demand conditions, which can create overheat complaints. In ‘99-later vehicles, the factory EPC pressure was set high at idle, resulting in engine surge conditions. Sonnax oversized line-to-lube pressure regulator and boost valve kit 34200-36K provides a significant increase in cooler flow under low RPM and high pressure conditions.

  • Oversized pressure regulator valve has an encapsulated check valve that allows regulated flow to the converter charge/lube circuit at vehicle idle
  • Check valve prevents converter or pump drainback
  • Improves converter release pressure

  • Patent No. 7,351,176

Required Tools

Related Parts

You need this if...

A vacuum test at the port indicated fails to hold at least 14 in-Hg.

  • Test Locations

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Related Tech Articles

Sonnax

GM 4L80-E Vacuum Test Guide

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