DETROIT DIESEL 53
1.0
SHOP NOTES - TROUBLE SHOOTING - SPECIFICATIONS
SERVICE TOOLS
SHOP NOTES
TEFLON WRAPPED PIPE PLUGS
Pipe plugs with a baked teflon coating are available for service. However, pipe plugs can be hand wrapped satisfactorily
with teflon tape to provide a better seal and facilitate plug removal. When a teflon wrapped plug is installed, it is
extremely important that the specified torque not be exceeded.
Hand wrap a pipe plug with teflon tape as follows:
1. Be sure the pipe plug is thoroughly clean and dry prior to applying the teflon tape. All dirt, grease, oil and scale must
be removed.
2. Start the tape one or two threads from the small or leading edge of the plug, joining the tape together with an-overlap
of approximately 1/8".
3. Wrap the tape tightly in the same direction as you would turn a nut. The tape must conform to the configuration of the
threads (be pressed into the minor diameter of the threads) without cutting or ripping the tape.
4. Hand tighten and hand torque the pipe plug and do not exceed the specified torque. Do not use power tools.
CHECKING BEARING CLEARANCE
A strip of soft plastic squeezed between the crankshaft
journal and the connecting rod bearing or main bearing may
be used to- measure the bearing clearances.
The strip is a specially molded plastic "wire" manufactured
commercially and is available in three sizes and colors.
Type PG-1 (green) has a clearance range of .001 "to .003",
type PR-1 (red) has a range of .002" to .006" and type PB-1
(blue) has a range of .004" to .009" .
The plastic strip may be used for checking the bearing
clearances as follows:
1. Remove the bearing cap and wipe the oil from the
bearing shell and the crankshaft journal.
NOTE: When checking the main bearing
clearances with the engine in a position where the
main bearing caps are supporting the weight of
the crankshaft and the flywheel, an erroneous
reading, due to the weight of the crankshaft and
flywheel, can be eliminated by supporting the
weight of the crankshaft with a jack under the
counterweight adjoining the bearing being
checked.
2. Place a piece of the plastic strip the full width of the
bearing shell, about 1/4 " off center (Fig. 1).
3.Rotate the crankshaft about 30 from bottom dead center
and reinstall the bearing cap. Tighten the bolts to the
specified torque.
Fig. 1 - Using Plastic Strip to Measure
Bearing-to-Crankshaft Clearance
April, 1974
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