TM 55-1930-209-14&P-21
b
Inspection and repair
(1)
Check top of the block for flatness with an accurate straight edge and a feeler gage. Top surface must not
vary more than 0. 003 inch transversely and not over 0. 007 inch longitudinally.
(2)
Make sure liner seal ring grooves are clean. Then, inspect ring grooves and lands for evidence of pitting
and erosion. If grooves are eroded to extent that sealing is affected, block must be replaced.
(3)
Check main bearing bores as follows:
(a)
Reinstall main bearing caps in their original position. Lubricate bolt threads and underside of each
bolt head with engine oil and tighten bolts to high side of torque specified in Table 1-1.
CAUTION
It is imperative that main bearing caps are reinstalled in their original position to maintain bearing
bore alignment.
(b)
Measure main bearing bores. Bearing bores must be 3. 251 to 3. 252 inches. If bores do not fall
within these limits, replace block.
(c)
Check bearing bores for alignment. Bearing bores are aligned with one another if a crankshaft with
standard size journals can be rotated freely by hand, after new standard size main bearing shells have been installed and
lubricated as in step (a) above.
(4)
Pressure test cylinder block.
(a)
Make a 1/2 inch thick steel plate to seal top surface of cylinder block.
(b)
Make sure seal ring grooves in cylinder bores are clean, then install new rings in grooves (para 6-
17).
(c)
Apply a light coating of hydrogenated vegetable shortening or permanent anti-freeze to seal rings.
(d)
Install cylinder liners (para 6-37).
(e)
Install new compression gaskets, and water hole seal rings.
(f)
Secure steel plate with 5/8 inch-i 1 bolts and flat washers.
(g)
Install water hole cover plates and gaskets on side of block.
NOTE
One cover plate should be drilled and tapped for an air line connection.
(h)
Immerse cylinder block for 20 minutes in a tank of water heated to 180-200°F.
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