[212 Cv] Auxiliary Driveshaft; Description; Inspection; [212 Lp] Connecting Rods - Mack E7 Service Manual

5-101.bk Page 5 Friday, March 17, 2006 11:05 AM
CUTTING THE COUNTERBORE
Refer back to Figure 5-1.
1. Fill the oil fill tube (7) with 30W
nondetergent oil to maintain lubrication
during use.
2. Back off the lower depth-set collar (16) two
increments or less, and tighten the
thumbscrew (6) securely.
3. Cut the counterbore by turning the T-handle
clockwise while maintaining constant
downward pressure on the tool. Stop the
handle in a different position to avoid
creating a ridge in the counterbore.
4. Continue backing off the lower depth-set
collar, no more than two graduations per cut.
Check the depth measurement between
each adjustment. Plan to remove 0.001 inch
(0.025 mm) on the final cut to meet the final
predetermined counterbore depth. This
ensures achieving a very fine machined
finish.
5. Remove the tool from the cylinder bore.
a. Loosen the two cutter bit hold-down
capscrews (9) and rotate the cutter bit
adjusting screw (10) counterclockwise
until the cutter bit is retracted into the
cutter plate (13).
b. Remove the four machine hold-down
bolts (3) and special washers (4).
c. Remove the tool from the cylinder bore.
6. Follow steps 1 through 5 for the remaining
cylinders.
200 BENCH PROCEDURES
[212 CV] AUXILIARY
DRIVESHAFT

Description

All current production engines (effective
February 27, 1992, serial No. 2E1233) are
equipped with a "fast ratio" auxiliary driveshaft
assembly and oil pump assembly. This
arrangement raises oil pump speed to increase
operating oil pressure 25%. Refer to Auxiliary
Driveshaft Installation instructions in the ENGINE
ASSEMBLY section for ratio information.
Do not mix "fast ratio" and "standard ratio"
components. Serious damage may occur.

Inspection

1. Thoroughly clean auxiliary driveshaft.
2. Inspect auxiliary driveshaft journals and gear
teeth for evidence of cracks, pitting, scoring
or severe wear. If any of these conditions
exist, replace the auxiliary driveshaft.

[212 LP] CONNECTING RODS

Description
Refer to Figure 5-2.
Early E7 engine connecting rods were machined
to give rod cap bottoms a contoured appearance.
Since mid-1992, connecting rod caps have had a
flat, machined bottom. The rods are the same in
strength and configuration, with the only
difference being the rod cap bottom surface
machining.
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