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.
These improved TCC apply valves with PTFE seals will eliminate bore cross leakage.
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.
December 22, 2014
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Contact a Sonnax Parts Distributor.