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: CHANGE OF CONNECTING ROD NUTS AND TORQUE

Cadmium plated connecting rod nuts currently used on some engine types are gradually being changed to
phosphated nuts for purposes of standardization. The phosphated nuts, which are black in color require a
much higher torque than cadmium plated nuts, which are silver in color.

If for any reason a connecting rod cap is removed, new nuts must be installed and tightened to the correct
torque as shown in Table I.

A-A-87 R02

DATE: Feb. 20, 1982

MODEL: Perkins

Diesel Engines

Cadmium Plated

(Silver)

Engine Types

Phosphated

(Black)

45 lbf ft (61 Nm)

3.152
4.203
4.2032

TABLE I CONNECTING ROD NUT TORQUE

INTERCHANGEABILITY:

The two types of nuts can be used together in an engine, but not together on one connecting rod.

PARTS STOCK:

Use up P/N’s 176140 and 99663.

EFFECTIVE SERIAL NUMBERS:

Not affected.

60 1bf ft (81 Nm)

4.236
6.354
T6.354
6.3544
T6.3544

(Nut part number:
176140)

(Nut part number:
to be released)

75 1bf ft. (102 Nm)

(Nut part number:
99663)

95 1bf ft (129 Nm)

(Nut part number:
to be released)