A/T - 440T4 Channel Plate Gasket Blow-Out

BULLETIN # 141

TRANSMISSION: 440T4

SUBJECT: CHANNEL PLATE GASKET BLOW-OUT

APPLICATION: GM

440-CHANNEL PLATE GASKET BLOW-OUT




Complaints of no line pressure rise, delayed reverse engagements, slip in reverse, or premature second clutch failure, may be the result of blown out channel plate gaskets. To prevent these complaints always:

1. Flat file case and channel plate.
2. Use only embossed type gaskets.
3. Torque the channel plate bolts (13 mm hex heads and 40 torx heads) in 3 even steps, beginning at 8 ft. lb., then 16 ft. lb., and then finally 21 ft. lb.. Once all the large bolts are torqued to 21 ft. lb., go back over them a second time to ensure that no bolts have been missed.

4. Verify that line pressure, (at 1000 RPM in O/D, 0" vacuum) does not exceed 210 PSI.