TM 5-3895-346-14
CYLINDER BLOCK
ENGINE OVERHAUL
caps have been secured in place, and the bolts tightened to the specified torque. If a main bearing bore is
more than 0.001 inch out of alignment, the block must be line-bored or scrapped. Misalignment may be caused
by a broken crankshaft, excessive heat, or other damage.
d.
If the main bearing bores are not in alignment when a replacement bearing cap is used, the
block must be line-bored. Install the bearing caps in their original positions (without the bearing cap stabilizers)
and tighten the bolts to the specified torque (Specifications). Line-bore the block, but do not remove more than
O.001 inch stock. After boring, all bores must be within the specified limits of 3.251 to 3.252 inches.
5.
Refer to the Cylinder Block Plugging Charts shown as a fold out at the end of this manual and
install the necessary plugs and dowels.
6.
Replace loose or damaged dowel pins. The dowels at the ends of the cylinder block must extend
0.680 inch from the cylinder block face.
The dowels used to retain the crankshaft thrust washers on the rear main bearing cap must extend 0.107 to
0.117 inch from the surface of the bearing cap.
NOTE
A stepped dowel pin is available to replace loose pins in the rear main bearing cap.
Before installing the stepped pins, rebore the dowel holes in the bearing cap with a
No. 11 (0.1910 inch) or No. 12 (0.1890 inch) drill. After pressing the pins into the
bearing cap, remove all burrs from the base of the dowel pins to ensure proper
seating of the thrust washers.
7.
Check all of the machined surfaces and threaded holes in the block. Remove nicks and burrs from
the machined surfaces with a file. Clean up damaged threads in tapped holes with a tap or install helical thread
inserts.
8.
After inspection, if the cylinder block is not to be used immediately, spray the machined surfaces
with engine oil. If the block is to be stored for an extended period of time, spray or dip it in a polar-type rust
preventive such as Valvoline Oil Company's Tectyl 502-C, or equivalent. Castings free of grease or oil will rust
when exposed to the atmosphere.
Assemble and Install Engine
After the cylinder block has been cleaned and inspected, assemble the engine as follows:
CAUTION
Before a reconditioned or new service replacement cylinder block is used, steam
clean it to remove the rust preventive and blow out the oil galleries with
compressed air.
1.
Mount the block on the overhaul stand.
2.
If a new service replacement block is used, stamp the engine serial number and model number on
the upper rear corner of the in-line block. Also stamp the position numbers on the main bearing caps (Fig. 11)
and the position of the No. 1 bearing on the oil pan mounting flange of the block.
3.
Install all the required plugs and drain cocks. Use a good grade of nonhardening sealant on the
threads of the plugs and drain cocks. If a new service replacement block is used, make sure the top surface is
plugged correctly to prevent low oil pressure or the accumulation of abnormal quantities of oil in the cylinder
head.
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