ENGINE FRONT COVER (LOWER)
ENGINE FRONT COVER (Lower)
The engine lower front cover is mounted against the cylinder block at the lower front end of the engine (Fig. 1).
It serves as a housing for the crankshaft front oil seal, the lubricating oil pump, the oil pressure regulator valve,
and the oil cooler bypass valve. The cleanout openings in the periphery of the current cover incorporate tapped
holes and 1/2-14 threaded plugs.
On all in-line engines effective with engine serial number 4D-6027, the oil pressure regulator valve is located
on the right-hand side of the engine front cover, as viewed from the front of the engine. Prior to the above
engine serial number, the oil pressure regulator valve was located on the left-hand side of the front cover just
below the oil cooler bypass valve.
Figure 1. Engine Front Cover Mounting (Lower) - In-Line Engine Remove Engine Front Cover
Drain the oil and remove the oil pan.
Remove the crankshaft pulley as outlined in Crankshaft Pulley.
Remove the two bolts and lock- washers that secure the lubricating oil pump inlet tube flange or
elbow to the engine front cover.
Remove the bolts and lockwashers that secure the engine front cover to the cylinder block.
Strike the cover with a soft hammer to free it from the dowels. Pull the cover straight off the end of
Remove the cover gasket.
Inspect the oil seal and lubricating oil pump as outlined in Crank- shaft Oil Seals and Oil Pump.
Also check the oil pressure regulator valve and oil cooler bypass valve as outlined in Oil Pressure Regulator
and Lubricating Oil Cooler.
Install Engine Front Cover
Affix a new cover gasket to the cylinder block.
Install oil seal expander J 7454 over the front end of the crankshaft.
Thread two 3/8-16 pilot studs approximately 8 inches long into two diametrically opposite boltholes
in the cylinder block to guide the cover in place (Fig. 2).
Apply a light coat of cup grease to the lip of the oil seal. Slide the engine front cover over the oil
seal expander and pilot studs as shown in Fig. 2. Push the cover forward until the inner rotor of the oil pump