

Issue Summary:
- We provide exploded views of the Aisin Seiki 450-43LE valve body and identification of its components.
- Before or after overhaul, some Volvo models equipped with the AW 55-50 SN transaxle may exhibit a neutral bang on takeoff.


Refer to figure 1 for the identification and locations of valve line-ups in the upper valve body.

Refer to figure 2 for the identification and locations of valve line-ups in the lower valve body.

Refer to Figure 3 for the identification and locations of the shift solenoids, lockup solenoid and timing solenoid.

Refer to Figure 4 for the locations of checkballs and filters in the upper valve body.

Refer to Figure 5 for the locations of checkballs in the lower valve body.

Refer to Figure 6 for the locations of the retainers and filters in the lower valve body (pan side).





Some Volvo models equipped with the AW 55-50 SN transaxle (see Figure 7) may exhibit a neutral bang on takeoff before or after overhaul.


The cause may be that when the accelerator pedal is depressed rapidly, the customer feels a re-engagement of the C1 clutch on takeoff because of a software issue in the transmission control module.

To correct this complaint, the TCM will have to be reflashed by a Volvo dealer, which will deactivate or desensitize this feature. TCM 012B Neutral Control Flash.

- TCM upgrade number (Volvo) . . . . . . . . . . . . . . .30677036


August 2006 Issue
Volume 23, No. 8
- Aisin Seiki 450-43LE: Exploded Views of Valve Body and Identification of Components
- Volvo AW55-50 SN: Neutral Bang on Takeoff