A/T - 1st To 2nd Gear Shift Shock Modification

91nissan04

Classification: Section:
Automatic
A/T91-004 Transmission

Reference:
TECHNICAL BULLETIN NTB91-062


Models: 1990-91 Truck
Date: June 13, 1991


TRUCK A/T MODIFICATION FOR SHIFT SHOCK

APPLIED MODEL: 1990-91 Truck (D21) with RL4R01A Transmission

APPLIED UNIT DATE: January 1, 1991

APPLIED UNIT NUMBER: 0Z55915


SERVICE INFORMATION

Some 1990-91 Trucks with the RL4R01A automatic transmission, built before the applied date, may exhibit D1 - D2 shift shock. This incident may be caused by a worn orifice check valve. When excessive wear occurs to the orifice check valve, it may break into pieces and collect in the 1 - 2 accumulator valve. The orifice check valve and spring have been eliminated on vehicles produced after the applied date. The control valve part number has not been changed.





SERVICE PROCEDURE

Remove the orifice check valve and orifice check spring. Inspect the orifice check valve for wear or damage (see illustration). If the check valve is broken, inspect the 1 - 2 accumulator for pieces of the check valve. Clean the accumulator as necessary.

The check valve and orifice check spring should be discarded even if there is no wear or damage. Removal of this part will not affect the operation of the transmission.