VALVE GP-PRESSURE CONTROL 8P7790 - Caterpillar

3406 Marine and 3408 Truck EnginesDescription of Change: More torque is now used to tighten the retainer nut for the turbocharger compressor on 3406 Marine and 3408 Truck Engines equipped with Schwitzer turbochargers. Formerly, it was possible for the nut to loosen.Adaptable To: The new torque is used only on those Schwitzer turbochargers made after July 15, 1976. Before this date, a softer material was used to make the compressor shafts and less torque was needed on the retainer nut. After July 15, 1976, the compressor shafts were made of a harder material and more torque was needed. To tell which turbocharger your 3406 Marine or 3408 Truck Engine is equipped with, look at the nameplate on the turbocharger housing. Any Schwitzer turbocharger with a date code of *G1576 or later must have the retainer nut for the compressor tightened to a torque of 44 2 lb ft (60 3 N m). Turbochargers with an earlier date code must have the retainer nut tightened to 32 2 lb ft (43 3 N m).
*Explanation of Date Code- Letters A-L are the months January through December, respectively.- The second and third numbers are the day of the month.- The fourth and fifth numbers are the year.EXAMPLE: G1576 = July 15, 1976.