Oil Pump

REMOVAL & INSTALLATION

1978–80 GLC and 1979–82 626

1. Drain the crankcase and remove the oil pan, as previously described in this section.
2. Remove the nut and lockwasher, then disengage the oil pump sprocket and chain.
3. Unfasten the bolts attaching the oil pump to the block and remove the pump assembly.

   To install:

4. Fit the O-ring to the outlet hole on the oil pump and align the dowel pins. Attach the oil pump to the engine block.
5. Wrap the oil pump drive chain around the sprocket, then slide the sprocket onto the shaft. Be sure to align the key on the oil pump shaft with the keyway of the pump sprocket.
6. Tighten the nut and lockwasher to secure the sprocket.
7. Install the oil pan, as previously described in this section.
8. Fill the crankcase to the proper level. Start the engine and check for leaks.

Front Wheel Drive GLC

1. Drain the crankcase and remove the oil pan, as previously described in this section.
2. Remove the oil pump mounting bolts, disengage the drive chain, and remove the pump.

   NOTE: If the sprocket must be separated after the pump has been removed, it will have to be pressed off the pump shaft using a suitable support and a press that can develop as much as 3,000 lbs. pressure. Reinstall the sprocket using 1,540–2,860 lbs. of pressure until the sprocket's outer edge is flush with the outer end of the shaft.

   To install:

3. Wrap the oil pump drive chain around the sprocket, then position the oil pump to the engine block. Fasten the oil pump mounting bolts.
4. Install the oil pan, as previously described in this section.
5. Fill the crankcase to the proper level. Start the engine and check for leaks.

GLC Wagon

1. Position a suitable drain pan beneath the engine's front cover.
2. Remove the crankshaft pulley, front cover and oil slinger, as described later in this section.
3. Remove the oil pump drive sprocket retaining nut and lockwasher. Slide both oil pump drive chain sprockets and the chain off the crankshaft and oil pump shaft. Be careful not to lose the sprocket keys.
4. Remove the oil pump cover, then withdraw the pump shaft and rotor assembly.

   To install:

5. Position the oil pump shaft and rotor assembly in the engine block.
6. Attach the oil pump cover, then insert the key into the oil pump shaft.
7. Wrap the oil pump drive chain around both sprockets, then align and slide the sprockets onto the crankshaft and oil pump shaft.
8. Hand-start the oil pump drive sprocket lockwasher and retaining nut, then torque the nut to 22–25 ft. lbs. (30–34 Nm).
9. Position the oil slinger, so that its keyway is aligned with those of the crankshaft sprockets, then insert the key.
10. Install the front cover with new gaskets. (Don't forget to remove the drain pan.)
11. Install the crankshaft pulley.

1983–87 626

1. Rotate the engine so that the No. 1 cylinder is at TDC. Remove the timing belt cover and timing belt, as described later in this section.
2. Remove the retaining bolt and, using a puller, remove the lower timing belt sprocket.
3. Raise and safely support the front of the vehicle.
4. Drain the crankcase and remove the oil pan, as described earlier in this section.
5. Unfasten the bolts which secure the oil strainer's pickup tube and brace, then remove the oil strainer.
6. Remove the pump mounting bolts and pump body from the front of the engine.

   NOTE: The inner and outer gears may be removed and inspected after unfastening the pump cover plate.

   To install:

7. If disassembled after removal, coat a new oil seal lip with engine oil, then install the seal, taking care not to damage the lip.
8. Coat the O-ring with grease and install it over the oil hole at the top right of the pump, viewed from the rear. Coat all sealing surfaces that contact the front of the block with sealer. Keep sealant out of the oil passages.
9. Position the pump body and torque the mounting bolts to 14–19 ft. lbs. (19–26 Nm).
10. Position and fasten the oil strainer, using a new gasket.
11. Install the oil pan, as described earlier in this section.
12. Lower the vehicle, then install the timing belt sprocket.
13. Install the timing belt and timing belt cover, as described later in this section.
14. Fill the crankcase to the proper level. Start the engine and check for leaks.

323 and 1988–89 626/MX-6

1. Remove the front cover and timing belt, as described later in this section.
2. Remove the bolt at the center of the lower timing belt sprocket, then remove the sprocket and key.
3. Drain the crankcase and remove the oil pan, as described earlier in this section.
4. Unbolt and remove the oil strainer and its gasket.
5. Unfasten the bolts from the oil pump housing (lower front of the block), then remove the pump.

   To install:

6. Position the oil pump and install the retaining bolts. On 323s, torque the bolts to 14–19 ft. lbs. (19–26 Nm). On 1988–89 626/MX-6s, torque the M8 (smaller) bolts to 14–19 ft. lbs. (19–26 Nm) and the M10 (larger) bolts to 27–38 ft. lbs. (37–51 Nm).
7. Position and fasten the oil strainer, using a new gasket.
8. Install the oil pan, as described earlier in this section. On 323s, torque the retaining bolts to 6–7 ft. lbs. (8–9 Nm). On 1988–89 626/MX-6s, torque the retaining bolts to 5–9 ft. lbs. (7–12 Nm).
9. Align the timing belt sprocket and keyway, then install the timing belt sprocket and key.
10. Install the timing belt and front belt cover, as described later in this section.
11. Fill the crankcase to the proper level. Start the engine and check for leaks.

1988–89 929 With Positive Displacement Gear Pump

NOTE: Models which have a positive displacement gear-type oil pump are identifiable by the absence of a pressure regulator cover in front of the automatic timing belt tensioner. Please refer to the accompanying illustration.

1. Disconnect the negative battery cable.
2. Raise and safely support the front of the vehicle.
3. Drain the engine oil. Remove the engine under cover.
4. Unfasten the oil pan retaining bolts, then remove the oil pan, as described earlier in this section.
5. Remove the oil pump and strainer assembly retaining bolts. Remove the oil pump assembly from its mounting.
6. Remove the oil pump driveshaft and O-ring.

   To install:

7. Install a new O-ring on the oil pump body.
8. Insert the pump driveshaft into the engine, and manually rotate to check for smooth operation.
9. Insert the other end of the driveshaft into the oil pump, then mount the pump/strainer assembly to the engine block. Torque the oil pump retaining bolts to 6–8 ft. lbs. (8–11 Nm).
10. Install the oil pan, as described earlier in this section. Be sure to use new gaskets or RTV sealant, as required.
11. Install the engine under cover, then lower the vehicle.
12. Fill the crankcase to the proper level.
13. Connect the negative battery cable. Start the engine and check for leaks.

    Fig. 1: The trochoid gear oil pump is identifiable by a pressure regulator cover in front of the automatic timing belt tensioner; the positive displacement gear oil pump has no such cover

1989 929 With Trochoid Gear Pump

NOTE: The trochoid gear-type oil pump is not used on 1988 models. All 1989 models which are equipped with this type of pump are identifiable by a pressure regulator cover in front of the automatic timing belt tensioner. Please refer to the accompanying illustration.

1. Disconnect the negative battery cable.
2. Raise and safely support the vehicle.
3. Drain the engine oil and the cooling system.
4. Remove the associated pulleys and the timing belt, as described later in this section.
5. Remove the thermostat and gasket.
6. Remove the oil pan, as described earlier in this section. Remove the oil strainer and O-ring.
7. Unbolt and remove the oil pump and gasket.

   To install:

8. Position the oil pump with a new gasket. Install and torque the oil pump retaining bolts to 14–19 ft. lbs. (19–26 Nm).
9. Install the oil strainer, using a new O-ring.
10. Install the oil pan, as described earlier in this section.
11. Install the thermostat with a new gasket.
12. Install the timing belt and associated pulleys, as described later in this section.
13. Lower the vehicle. Fill the crankcase and cooling systems to their proper levels.
14. Connect the negative battery cable. Start the engine and check for leaks.