TRUCK SERVICE MANUAL
The new counterbore salvage sleeve Part No. 202226 is a
a. Find this dimension by placing block, top down, on a
precision sleeve. No inside diameter cutting is required except
flat surface plate and measuring from main bearing bore
cutting the counterbore ledge to depth. When installed 0.005
centerline to plate.
inch [0.13 mm] to 0.010 inch [0.25 mm] must be cut from the
b. An alternate method is to check distance from installed
counterbore ledge to meet specification, Table 1-1 (2).
main bearing bore alignment bar to top surface of block (2,
Cylinder Head Capscrew Threads
c. Distance from head surface to main bearing bore
centerline must not vary more than 0.002 inch [0.05 mm]
If threads are damaged, block may be repaired by using ST-
throughout length of block. Head surface flatness must not
476 Heli-Coil Kit.
vary over 0.002 inch [0.05 mm].
1. If capscrew hole is 2-11/32 inch [59.53 mm] deep,*
4. Finish surfaces to .125 R.M.S.
drill hole to depth of 1-7/8 inch [47.63 mm] with 23/32 inch drill;
5. Resurface counterbore to obtain proper liner
tap to 1-3/4 inch [44.45 mm] depth.
protrusion. Check liner to block contact in crevice seal area.
2. If capscrew hole is 2-9/16 inch [65.09 mm] deep,* drill
hole to 2-1/16 inch [52.39 mm] depth with a 23/32 inch drill;
Lower Liner Packing Ring Bore Repair -
tap to 1-15/16 inch [49.21 mm] depth. Clean all chips and
Installation Of Cast Iron Sleeve
shavings from repair hole.
Use ST-1081 Boring Tool as indicated in Service Tool
3. Install insert, Part No. 102674, to a depth of 1/2 inch
Instructions, Page 343, when installing 195778 cast iron
[12.70 mm] for Step 1, and 11/16 inch [17.46 mm] for Step 2
sleeves in lower bore of block.
below top surface of block. Break off insert tang, using a
punch and hammer, not an inserting tool; remove tang from
bottom of hole with a magnet.
Machining Lower Bore Entry Chamber
* The specified dimensions are obtained by using a depth
If the lower bore or the lower bore entry chamfer is beyond the
tolerances, pitted, or eroded, one of the following operations
gauge with a 1/4 inch wide blade seated in center taper of'
may be performed to salvage the cylinder block.
Main Bearing Capscrew Threads
If the erosion has occurred only on the entry chamfer and not
If threads are damaged, block may be repaired by installing
in the packing ring sealing area, the chamfer may be "built-up"
Heli-coil insert using ST-1230 Hell-Coil Kit as follows:
by the use of a plastic steel compound such as Devcon Plastic
Steel, Type "A." The manufacturer's directions should be
1. Drill out old threads with a 1-1/32 inch drill to a depth
followed for this salvage procedure.
of 2.675 to 2.705 inches [68.16 to 68.74 mm] from the main
bearing cap pad.
Check the chamfer depth after this operation and resurface the
2. Tap drilled hole with Tap No. 9193-16H4 to a depth
chamfer if beyond acceptable tolerances. Follow Service Tool
of 2.425 to 2.455 inches [61.60 to 62.36 mm].
Instructions, Page 343,
3. Install insert, Part No.
inserting tool No. 535-16 until insert is to a depth of 0.860 to
Cylinder Liner Counterbore
0.890 inch [21.84 to 22.61 mm] below cap mounting pad.
4. Break off tang using tang break-off tool No. 1196-16.
(Do not use inserting tool.)
Resurface cylinder liner counterbore if block has been
resurfaced, ledge is uneven or where liner protrusion is
ST-676 or ST-1059 Counterbore Tool with
appropriate adapter plate can be used for this operation. See
Cummins cylinder liners form combustion chamber walls and
Service Tool Instructions, Page 343.
are in direct contact with coolant for efficient cooling. Coolant
is sealed in block by accurately machined surfaces at liner
Rebuilding Cylinder Liner Counterbores
flange and by packing rings and crevice seal at lower end of
ST-1168 Cylinder Liner Counterbore Salvage Tool will enable
salvaging a block which has a damaged or cracked
counterbore ledge. ST-1166 Magnetic Crack Detecting Tool
may be used to determine the extent of cracks. The bores can
be enlarged and a new sleeve installed. See Service Tool
Instructions, Page 343,