CHAPTER 3. REPAIR OF ENGINE COMPONENTS

TM 5-4320-234-34

CHAPTER 3

REPAIR OF ENGINE COMPONENTS

Section I. GENERAL

3-2. Scope

3-1. Introduction

Only those components which are solely within the

This chapter provides you with repair and overhaul

scope of direct and general support maintenance are

instructions for various engine components. It includes

covered. For repair of components which are within the

information regarding disassembly, inspection of parts,

scope of operator/crew and organizational maintenance,

repair, and overhaul.

refer to TM 5-4320-234-12.

Section II. REPAIR OF GOVERNOR

carburetor and as the engine speed tends to increase,

3-3. Description

the throttle is closed slightly, decreasing the engine

speed. The decrease in engine speed decreases the

Engine speed is controlled by the inter-operation

centrifugal force of the balls, and the dished race moves

of the governor and the carburetor. The governor is a

axially toward the balls. This movement is sensed by

variable-speed type and is driven by the timing gear on

the fork which, in turn, transfers the movement to the

the end of the camshaft. The driver on the drive shaft

external governing lever. The governing lever opens

of the centrifugal flyball governor engages four

the carburetor throttle, increasing the engine speed. In

hardened steel balls. As the engine runs, centrifugal

this manner, a balanced condition is reached, and the

force throws the balls outward. As the engine speed

engine speed remains constant at the level determined

increases, the centrifugal force increases. This causes

by the throttle control setting.

Adjustment of the

the balls to exert pressure against a dished race, forcing

governor is made by changing the tension of the spring

the race to move axially away from the rotating balls.

which applies tens ion to the external governing lever

The movement of the dished race is transferred to a

and tends to keep the dished race against the flyballs.

drive fork through a thrust bearing. The fork is pinned to

Tightening the spring raises engine speed at any

the governing shaft which pivots as the drive fork

particular throttle control setting. Decreasing spring

moves. An external governing lever on the end of the

tension lowers the speed.

control shaft is connected to the throttle control on the

3-1