TM 5-3825-226-24
BASIC BLOCK
LATER FEED MECHANISM
A. Lever.
Place adapter (24) into boring bar and tightening
setscrew (25).
ADAPTER INSTALLED
24. 1 P2364 Adapter. 25. Setscrew.
Apply layout bluing to the bearing cap and bearing
bore. Oil the centering rings. Do not use lubricant on
the cutter. Use a one-half inch electric drill with
universal joint (26) to feed tool through the bore.
Service main bearings with .010 in. (0.25 mm) oversize
outside diameter are available to permit the bore to be
bored oversize. Bore the bore to 3.7175 ± .0005 in.
(94.425 ± 0.013 mm).
BORING BEARING BORE
26. 1P2363 Universal.
NOTE: If you use the later feed mechanism, the tool
can be driven from either the boring bar or the feed
mechanism.
DRIVING THROUGH FEED MECHANISM
(Typical Example)
26. 1P2363 Universal.
The bluing applied to the bearing bore indicates the
condition of the bore at the correct bore size. If bluing
shows an out of round condition, check the largest
diameter (indicated by remaining bluing) in relation to
the smallest diameter (indicated by lack of bluing). The
difference of the two must not exceed .0010 in. (0.025
mm).
If bluing indicates a step in the joint face, measure
the diameter at the step in relation to the smallest
diameter. A step of .0005 in. (0.013 mm) on one or
both sides is permissible. A maximum of .0010 in.
(0.025 mm) over the nominal finish bore diameter is
permissible if within the described limits.
To check the bore diameter, set the IP3535 Dial Bore
Gauge to 3.7175 in. (94.425 mm).
CHECKING BORE
(Typical Example)
LINE BORING MAIN BEARING BORES
Line bore all main bearing bores if bearing caps or
saddles are distorted.
Clean bearing caps and saddles. Remove all nicks
from pan rail. Plug oil holes in block with grease to
prevent chips from entering oil passages.
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