Cub Cadet MTD P90 Series - Manual (Page 57)

Lubrication
51
Lubrication system
The 4P90 engine uses a combination pressurized and
splash lubrication system. There is an oil pump in the
sump that is driven by the balance shaft.
The oil is drawn into the pump through a pre-screen.
The pump pushes the oil through a relief valve then into
the oil filter. From the filter, the oil flows through a passage
in the sump cover until it reaches the crankshaft PTO
bearing. The oil passes through the PTO bearing and is
forced into a passage in the crankshaft. The oil follows this
passage to the crankshaft crankpin. It is forced out
between the crankshaft and the connecting rod.
The rest of the engine is lubricated by the oil mist cre-
ated by the moving parts in the sump.
The oil in the head drains back into the sump through a
passage cast into the cylinder block.
Testing the oil Pump
To test the oil pump:
1. Allow the engine to cool.
2. Connect an oil pressure tester to the engine.
NOTE: There are two methods that can be used to con-
nect an oil pressure tester:
A. Kohler oil pressure test kit #25 761 06-S
1a. Remove the oil filter.
1b. Thread the oil pressure tester onto the oil filter
nipple. See Figure 5.4.
B. Connecting an oil gauge to the port in the sump
cover.
1a. Remove the oil plug from behind the oil filter
base using a 12mm wrench.
1b. Install an M8 x 1.25 male to 1/8” NPT female
adapter on to the oil pressure gauge.
NOTE: Mem-co part # ”M8 to 1/8 F” can be used.
1c. Thread hose and adapter from oil pressure
gauge into the port hand tight.
Figure 5.3
Dipper Oil pump
Balance shaft
Oil filter
Figure 5.4
Kohler oil pressure tester
Figure 5.5
Adapter