We reserve the right to make changes in design or add improvements without incur-
ring the obligation to make such changes in equipment previously manufactured.
H6030

PARTS-SERVICE

GRAM

SUBJECT: Improved Perkins T6.3544 Pistons and Rings

Turbocharged Perkins 6.3544 pistons and rings have been improved to reduce engine oil consumption.
Field complaints of high oil consumption in engine, 267930, can be resolved by installing the new parts per
the interchangeability reguirements below.

PARTS INVOLVED:

A-A 85

Model: H300-350B

Date: February 20, 1980

Engine

New Part Number

Description

Original Part Number

*Includes piston, pin and circlips.

INTERCHANGEABILITY:

Interchangeability on engines prior to serial number T63544U 562025F.

a) The new piston and ring pack can be used in sets of six to service engines prior to the above engine

serial number.

b) If only one piston requires changing, then the new piston and ring pack can be used as a replacement.

c) If more than one piston is to be changed, and the new pistons are to be used in engines prior to the

above serial number, then this is only acceptable in fitted pairs, i.e. No. 1 and 6 cylinders, No. 2 and 5
cylinders, No. 3 and 4 cylinders. To achieve this pairing, pistons may be transferred from cylinder to
cylinder.

The above restriction is necessary because the new piston is lighter than the original and the mixing of
pistons in an engine, other than as indicated above, will lead to an out-of-balance situation and possible
engine vibration.

d) Although the new piston ring pack will fit the original piston, it does not in itself provide an improvement

in oil control. It is, therefore, recommended that when rectifying a complaint of oil consumption, the
latest piston assembly and ring pack be used.

e) The original piston assembly 303749 and ring pack 303751 should not be fitted as service replacements

after serial number T63544 U562025F.

312782

Piston Assembly*

303749

312784

Ring Pack

303751

f)

Where pistons are moved between cylinders to obtain the balanced pairing, it is suggested that the
pistons be re-numbered with their new cylinder position number.

PARTS STOCK:

Not affected.

SERIAL NUMBER BREAK:

A-A 85
February 20, 1980
Page 2

Engines following serial number T63544 U56202F, are equipped with piston, 312782, and ring pack,
312784.