DETROIT DIESEL 53
SHOP NOTES - TROUBLE SHOOTING -
SPECIFICATIONS - SERVICE TOOLS
TEFLON WRAPPED PIPE PLUGS
Start the tape one or two threads from the small
Pipe plugs can be hand wrapped satisfactorily with
or leading edge of the plug, joining the tape together
teflon tape to provide a better seal and facilitate plug
with an overlap of approximately 1/8" .
removal. When a teflon wrapped plug is installed, it is
extremely important that the specified torque not be
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
Hand wrap a pipe plug with teflon tape as follows:
diameter of the threads) without cutting or ripping the
Be sure the pipe plug is thoroughly clean and
dry prior to applying the teflon tape. All dirt, grease, oil
Hand tighten and hand torque the pipe plug and
and scale must be removed.
do not exceed the specified torque. Do not use power
CHECKING BEARING CLEARANCES
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"
The plastic strip may be used for checking the bearing
clearances as follows:
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.
Fig. 1. - Using Plastic Strip to Measure
Place a piece of the plastic strip the full width of
the bearing shell about "off center (Fig. 1)
1972 General Motors Corp.
SEC. 1.0 Page 1