Figure 4-56. Checking Top Face of Cylinder Block.

TM 55-1930-208-24

4-16. BLOCK, CYLINDER-Continued.

d. Inspection.

(1) Check the top of the block for flatness with an accurate straight edge and a feeler gage as shown in figure

Figure 4-56. Checking Top Face of Cylinder Block.

(2) The top surface of the block must not vary more than .003 inch transversely and not over .007 inch

longitudinally. Cylinder block must be replaced if the top surface exceeds these tolerances.

(3) Check the main bearing bore diameters with the main bearing caps in their original positions. Apply a

small quantity of International Compound No. 2 or equivalent, to the threads on the bolts and to the bolt

head contact area. Then install and tighten the bolts to 165-175 lb-ft (224-238 Nm) torque. The specified

bore diameter is 3.812 inch to 3.813 inch. If the bores do not fall within these limits, the cylinder block

must be replaced.

NOTE

Bearing caps are numbered to correspond with their respective positions in the cylinder block. It is

imperative that the bearing caps are reinstalled in their original positions to maintain the main bearing bore

alignment. Main bearing cap bolts are especially designed for this purpose and must not be replaced by

ordinary bolts.

(4) Finished and unfinished main bearing caps are available for replacing broken or damaged caps. When

fitting a finished replacement cap, it may be necessary to try several caps before one will be found to

provide the correct bore diameter and bore alignment. If a replacement bearing cap is installed, be sure to

stamp the correct bearing position number on the cap.

4-74