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Symptoms:
  • Code 1870
  • Falls out of lockup when hot
  • Fluid blown out fill tube
  • Lockup immediately after 2nd gear
  • No lockup
Cause:

Excessive pump bore-to-valve clearance allows TCC signal oil to leak past the spool, preventing lockup or causing lockup to disengage when hot. Additionally, converter feed can leak past the excessive clearance, combine with signal oil and cause premature lockup.

Correction:

These improved TCC apply valves with PTFE seals will eliminate bore cross leakage.

4L60-E, 4L65-E, 4L70-E

TCC Apply Valve Kit

Part No.

77805E-K

TCC Apply Valve Kit
  • 77805e-k_combo_1

  • TCC Apply Valve Kit

  • 77805e-k_details

Small_77805e-k_combo_1 Small_77805e-k Small_77805e-k_details

4L60-E, 4L65-E, 4L70-E

TCC Apply Valve Kit

Part No. 77805E-K

  • Valve Aluminum
  • Seal PTFE
  • Spring

Fits PWM units only.

Complaint:

  • Code 1870
  • Falls out of lockup when hot
  • Fluid blown out fill tube
  • Lockup immediately after 2nd gear
  • No lockup

Cause:

Excessive pump bore-to-valve clearance allows TCC signal oil to leak past the spool, preventing lockup or causing lockup to disengage when hot. Additionally, converter feed can leak past the excessive clearance, combine with signal oil and cause premature lockup.


Correction:

These improved TCC apply valves with PTFE seals will eliminate bore cross leakage.

  • Updated stroke pressure eliminates TCC drift on apply and updated exhaust control
  • PTFE seal eliminates cross leaking of converter signal oil and converter feed oil
  • Sonnax kit works in both early- and late-style PWM pumps when used with included spring
WARNING:

This part only fits PWM units, and mismatching PWM and non-PWM valves will cause rapid converter failure.

Identifying PWM vs. Non-PWM Units
If the OE valve features one spool at the location indicated here, you are working on a PWM unit. If the OE valve features double spools, you are working on a non-PWM unit and must use Sonnax TCC apply valve kit 77805-K. Do not rely on the OE valve material (steel vs. aluminum) to determine for whether the unit is PWM, as some early PWM pumps used steel TCC valves like the non-PWM pumps.

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