Figure 6-45. Fitting Bearings with Plastigage.

TM 10-3930-633-34

Figure 6-45. Fitting Bearings with Plastigage.

(2) Install cap and torque bolts to

specifications. Do not turn crankshaft while

Figure 6-46. Checking Crankshaft End Play.

Plastigage is in place.

(3) Zero the dial indicator. Push the

(3) Remove cap. Using Plastigage scale,

crankshaft forward and note the reading on the

check width of Plastigage at widest point to get

dial.

minimum clearance. Check at narrowest point to

(4) If the end play exceeds the wear limit,

get maximum clearance.. Difference between

replace the thrust bearing. If the end play is less

readings is taper of journals. See table 6-6.

than the minimum limit, inspect the thrust

(4) If clearance exceeds specified limits, try

bearing faces for scratches, burrs, nicks, or dirt.

0.001 or 0.002 inch undersize bearings in com-

If the thrust faces are not damaged or dirty, they

bination with the standard bearings. Bearing

probably were not aligned properly. Install the

clearance must be within specified limits. If 0.002

thrust bearing and align the faces following the

undersize main bearings are used on more than

procedure recommended under paragraph 6-29.

one journal, be sure they are all installed in

b. Flywheel Runout.

cylinder block side of bearing. If standard and

(1) Remove the spark plugs.

0.002 inch undersize bearings do not bring

(2) Install a dial indicator so that the in-

c l e a r a n c e w i t h i n d e s i r e d l i m i t s , refinish

dicator point rests on the face of the ring gear

c r a n k s h a f t journal, t h e n install undersize

adjacent to the gear teeth.

bearings.

(3) Push the flywheel and crankshaft for-

(5) After bearing has been fitted, apply light

ward or backward as far as possible to prevent

coat of engine oil to journal and bearings. Install

crankshaft end play from being indicated as

bearing cap. Torque cap bolts to specifications

flywheel runout.

(table 6-3).

(4) Set the indicator dial on the zero mark.

(6) Repeat procedures for remaining

Turn the flywheel one complete revolution while

bearings that require replacement.

observing the total indicator reading (TIR). If the

6-34. Crankshaft End Play and Flywheel Runout

TIR exceeds specifications, the flywheel and ring

Check

gear assembly must be replaced. See table 6-6.

a. Crankshaft End Play.

6-35. Crankshaft Rear Oil Seal

(1) Force the crankshaft toward the rear of

If the crankshaft rear oil seal replacement is

the engine.

the only operation being performed, it can be done

(2) Install a dial indicator so that the contact

in the vehicle as detailed in the following

point rests against the crankshaft flange and the

procedure. If the oil seal is being replaced in

indicator axis is parallel to the crankshaft axis

c o n j u n c t i o n w i t h a rear m a i n bearing

(fig. 6-46).

6-34