Crankshaft Bearings

together with lower halves of

(10) Remove front filler block (22) and seal

crankshaft bearing.

by taking out two bolts and washers.

(5) Insert a bearing-removing tool through

(11) Punch-mark the main bearing caps

oil-hole in crankshaft journal. Rotate

and the cylinder block to assure

crankshaft by hand so that tool forces

correct installation (fig. 11).

upper half of bearing out of

(12) Remove lock wires and take out two

crankcase.

Be sure to turn the

bolts and washers from each cap (11,

crankshaft so that the lock (stamped

12, 13, and 14, fig. 4). Note punch

ear) on the bearing half is raised out

marks on bearing caps (fig. 11).

of its notch. Repeat for all bearings.

(13) Lift bearing caps off dowel pins

(6)

Do not ream, scrape, or burnish

(14) Lift out the crankshaft and press off

crankshaft bearings. Replace bearing

crankshaft timing gear if necessary.

halves in pairs if they are in any way

b. Inspection and Service.

defective.

(1) Mount crankshaft in V-blocks, and use

(7) Coat new bearing halves with OE and

dial indicator to check alinement.

insert in same number as old halves

(2) Measure crankshaft journals at opposite

were removed.

points at several plac, using a

b. Clearance.

Crankshaft bearing clearance

micrometer. Replace crankshaft if

should be checked after new bearings halves have been

taper or out-of-round at journals

installed. Measurement should be taken with seals

exceeds 0.001 inch.

removed. The main bearing clearance should be 0.001

(3) Inspect crankshaft oil passages Make

to 0.0032 inch.

certain that they are free and

(1) When checking a bearing for clearance,

unobstructed. Clean with compressed

all other bearings must be installed

air and wire brush, if necessary.

with caps tightened firmly in place.

c. Installation. Reverse procedure in a above.

(2) Remove bearing cap and place a piece

Tighten connecting rod nut to 35 to 40 foot-pounds

of 0.002 by by 1-inch shimstock in

torque and crankshaft bearing capscrews to 85 to 90

bearing cap (fig. 12).

foot-pounds torque.

(3) Install bearing cap and tighten to 85 to

d. End Play. After crankshaft has been installed,

90 foot-pounds, using a torque

mount a dial indicator against some vertical surface of

wrench. If crankshaft rotates with a

the crankshaft, and use a pry bar to move the crankshaft

noticeable drag, clearance is correct.

back and forth. Use the indicator to measure the end

(4)

Clearance may be checked by

play. Normal end play is 0.005 inch to 0.009 inch. If

plastigage method if plastigage and

end play is excessive, remove the front main bearing;

special measuring gage are available.

replace it with a new one and check end play again.

If this method is used, do not rotate

crankshaft with plastigage in place.

28. Crankshaft Bearings

Fitting Crankshaft Bearings.

Install new

crankshaft bearing caps if original caps have become

a. Replacement. The engine is equipped with

damaged or broken. Do not file, dress down, or shim a

sleeve bearings which may be replaced in the manner

bearing cap (crankshaft or connecting rod) except when

and order indicated below without removal of the

installing a replacement cap, and then only for its

crankshaft.

original installation in the engine. Replacement caps

(1) Remove engine from truck (par. 12a).

conform to original caps in every respect, with the

(2) Remove oil pump (par. 16a) and inlet

exception of stud holes which are 1/64 inch larger, and

and outlet pipes.

bearing cap size which is 1/16 inch shorter. The caps

(3) Remove spark plugs if cylinder head is

must thus be properly fitted by shimming or filing to

installed.

obtain bearing clearance.

(4) Remove crankshaft cap bolts, and

remove crankshaft bearing caps

AGO 7010A