[219 Mu] Oil Pump; Description - Mack E7 Service Manual

5-101.bk Page 42 Friday, March 17, 2006 11:05 AM
Refer to Figure 6-50.
3. Install thrust washer (4) and secure it in
position with the patch-lock capscrews (3)
and hardened washers.
4. Torque the thrust washer retaining patch-
lock capscrews to 15 lb-ft (20 N m) using
torque wrench J 24406 or equivalent.
5. Install auxiliary driveshaft gear (2) on shaft
splines (5).
The auxiliary driveshaft and nut threads must be
clean and dry before assembly. Clean the
threads thoroughly with Brakleen€ or electrical
contact cleaner. Apply Loctite€ 271 or 277 to the
threads and install the nut.
6. Install auxiliary driveshaft nut (1) and torque
to 300 lb-ft (407 N m) using torque wrench
J 23775-01 or equivalent.
Figure 6-50 — Auxiliary Driveshaft Gear Installation
1. Nut
2. Auxiliary driveshaft gear
3. Capscrew
Page 6-42
200 ENGINE ASSEMBLY

[219 MU] OIL PUMP

Description

The oil pump is a gear-type pump. As the pump
rotates, a vacuum forms on the inlet side, drawing
oil from the crankcase through the oil pump inlet
pipe, and into the pump gear compartment. Oil
then passes through the regulating valve.
Regulated pressure then forces oil through the
discharge port into a drilled passage in the
cylinder block, which leads to the oil filter and
cooler. The oil is then distributed to all main parts
of the engine. If the oil filter is excessively
contaminated, the filter bypass valve will open,
allowing the unfiltered, contaminated oil to
continue through the engine.
Oil fed to the main bearings also travels through
the connecting rods into the piston wrist pins to
lubricate the pistons and cylinder sleeve
surfaces. Oil jets below the pistons, also fed by
the oil pump, spray the bottom of the pistons with
the pressurized oil to assist in removing some of
the heat from the pistons produced by
combustion. Oil is then returned, by gravity, to the
crankcase.
Do not mix standard-ratio oil pumps with fast-ratio
pumps. Damage to the engine will result.
Current fast-ratio oil pumps:
Former standard-ratio oil pumps:
4. Thrust washer
5. Shaft splines
Make sure the oil pump is in satisfactory condition
as described in the BENCH PROCEDURES
section of this manual.
Part No. 315GC459AM, with rear sump
Drive gear, No. 683GB284 (12 teeth)
Part No. 315GC460M, with rear sump
Drive gear, part No. 683GB287 (13 teeth)