Figure 4-81. Checking diaphragm coupler assembly clearance.

1. Using two 5 / 16-in. steel rods (A), hold fuel injection

pump

drive

coupler

sleeve

(nearest

the

pump)

stationary and rotate the other drive coupler sleeve

counterclockwise to remove backlash from the pump

drive shaft.

2. When backlash is removed and flat sides of drive

c o u p l e r mate, tighten four drive coupler bolts (B)

securely.

3. When flat sides of drive coupler sleeves (C) do not

mate when backlash is removed, the coupler sleeves

must be separated and reset. Separate coupler and push

sleeve of drive coupler on rear fan and accessory drive

housing (fig. 4-75) shaft toward drive shaft and from

hub splines. Adjust sleeve on splines so flat sides of

coupler half are alined. Torque tighten coupler bolts.

Lubricate drive coupler (fig. 4-80).

Figure

4-79.

Removing

fuel

injection

pump

drive

gear

train

backlash

and

setting

advanced

unit

retard position-splined

coupler.

Note. For proper assembly of coupler half to

diaphragm pack, place a pry bar between rear

fan and accessory drive housing and coupler half

and apply pressure to take up the end thrust of

drive gear. Measure clearance between coupler

half and diaphragm pack. This clearance cannot

exceed 0.050-inch or it will put undue stress on

the diaphragm pack causing early failure. If the

0.050-inch dimension cannot be achieved, it will

be necessary to remove fuel injection pump and

replace

coupler hall or complete coupling

assembly. Torque coupler half retaining nut to

900 inch-pounds when installing new coupler

half.

4-40

Figure 4-81. Checking diaphragm coupler

assembly clearance.