how to replace oil pump in 96 chevy s-10 6 cly 4.3l

OIL PAN REPLACEMENT

NOTICE: If the clearance between the rear of the oil pan and the transmission Is more than 0.254 mm (0.010 in.) powertrain durability may be impacted.

Important

Any time the transmission and oil pan are off of the engine at the same time, the transmission must be installed before the oil pan. This will allow the for proper measurement of the oil pan tolerance.
A one-piece type oil pan gasket is used.
Tools Required:

J 29107 Pittman Arm Puller
J 6632-01 Pittman Arm Remover

Remove or Disconnect

Negative battery cable.
Oil level indicator tube.
Raise the vehicle and support with safety stands.
Front axle shield.
Front under body shield.
Drain engine oil.
Wiring harness bracket at right side of the oil pan.
Left engine mount through bolts.
Right engine mount through bolts.
Raise the engine. Block in position.
Oil cooler line.
Oil filter adapter.
Pitman arm bolt.
Pitman arm.
Idler arm bolts.
Idler arm.
Front drive axle through bolts.
Front propeller shaft.
Roll differential forward.
Starter motor.
Oil pan bolts, nuts, and reinforcements.
Oil pan and gasket.
Rubber bell housing plugs.
Clean

Gasket surfaces on the engine and oil pan.
Inspect

Oil pan gasket for damage. Replace if necessary.

Oil Pan Clearance Alignment

Install or Connect

Apply sealant GM P/N 12346141 or equivalent to the front cover to block joint and to the rear crankshaft seal to block joint. Apply the sealant for 25 mm (1 inch) in both directions from each of the four corners.
Oil pan gasket to the oil pan.
Rubber bell housing plugs.
Oil pan to the engine.
Oil pan bolts and studs in sequence.
Important

The alignment between the rear of the oil pan and the rear of the block is critical. The two surfaces must be flush to allow for proper alignment with the transmission housing.
Measure

Use a feeler gage to check the clearance between the three oil pan-to-transmission contact points. If the clearance exceeds 0.0254 mm (0.010 in.) at any of the three points repeat the installation steps until the clearance is within specification.
Tighten

Oil pan bolts and studs to 25 N.m (18 lb. ft.) .
Install rubber bellhousing plugs as installing the oil pan.
Starter motor.
Align the differential into position.
Align the engine into position.
Front propeller shaft.
Front differential through bolts.
Idler arm.
Idler arm bolts.
Pitman arm.
Pitman arm bolt.
Oil cooler lines.
Oil cooler filter adapter.
Left engine mount through bolts.
Right engine mount through bolts.
Wiring harness bracket at right side of oil pan.
Front skid plate.
Front axle shield.
Drive belt splash shield.
Lower the vehicle.
Oil level indicator tube.
Proper quantity and grade of crankcase oil.
Negative battery cable.

OIL PUMP REPLACEMENT

REMOVAL

Remove oil pan.
Remove oil pump-to-main bearing cap attaching bolt.
Remove oil pump.
DISASSEMBLE

Remove pump cover attaching bolts and pump cover, Fig. 18 .
Mark drive and idler gear teeth so they can be installed in same position, then remove drive and idler gears and shaft from pump body.
Remove pin, spring and pressure regulator valve from pump cover.
If pickup tube and screen are to be replaced, mount pump cover in soft jawed vise and remove pickup tube from cover. Do not remove screen from pickup tube, as these components are serviced as an assembly.
INSPECTION

Inspect pump body and cover for excessive wear and cracks.
Inspect pump gears for damage or excessive wear. If pump gears are damaged or worn, the entire pump assembly must be replaced.
Check drive gear shaft for looseness in pump body.
Inspect pump cover for wear that would allow oil to leak past teeth.
Inspect pickup tube and screen for damage.
Check pressure regulator valve for fit in pump cover.
ASSEMBLE

If pickup tube and screen were removed, apply sealer to end of pickup tube, then mount pump cover in a soft jawed vise and using pickup screen and tube installer tool No. J-21882, or equivalent, tap pickup tube into place with a hammer. Whenever the pickup tube and screen have been removed, a new pickup tube and screen assembly should be installed. Ensure tube does not twist, shear or collapse when installing pickup tube and screen. Loss of a press fit condition could result in an air leak and loss of oil pressure.
Install pressure regulator valve, spring and pin, Fig. 18 .
Install drive gear and shaft in body.
Align marks made during disassembly, then install idler gear.
Install pump cover gasket, cover and attaching bolts. Torque bolts to specification.
Rotate pump driveshaft by hand and ensure smooth operation.
INSTALLATION

Align oil pump shaft with oil pump driveshaft.
Install oil pump attaching bolts and torque to specification.
Install oil pan.

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