- Distributor Part Numbers
- General Details
1998 and newer Toyota and Lexus vehicles equipped with the U140, U240 and U241 series automatic transmissions with high mileage often have worn out B1 switch boost valve and bushing as well as the main line pressure boost valve and bushing.
The computer determines the appropriate line pressure value in accordance with the calculated load input. The ECM will then send the amount of current needed to the SLT solenoid to raise or lower the main line pressure in accordance to the driving conditions. Adequate main line pressure is required to provide enough clamping force under all load conditions to prevent slipping as well as to achieve proper shift quality. A compromised EPC boost valve and bushing will cause complaints of slow or lazy pressure boost, flare shifts, burnt frictions and burnt lock-up clutch can occur. These can also be accompanied by a wide variety of gear ratio, shift and solenoid performance codes.
Main line pressure also acts on the B1 switch boost valve to control when it applies. Consequently, when that boost valve sticks, proper apply and release of the B1 is impaired causing no 2nd gear or 2nd gear starts.
Features and benefits:
The TransGo drop-in USA-made hardened steel boost valves and bushings assembly provides you with a durable direct replacement for the soft aluminum OEM assembly that are prone to wear.
- Insufficient line rise
- Soft, slipping or flaring shifts
- Codes P0750, P0753, P0758, P0765, P0770, and P1760
- USA-made hardened steel main line boost valve and bushing
- Gold shim (for some applications)
- USA-made hardened steel B1 switch boost valve and bushing
Using # SK U140 with this boost kit is an excellent way to prevent common problems in these high mileage Toyota/Lexus 4-SPD FWD transmissions and are a key part of a successful repair.