Vespa GTS Super 300 ie - Service manual > Crankshaft oil seals

Removal

• Remove the transmission cover and the complete drive pulley beforehand

• Install the base of the appropriate tool on the oil seal using the screws provided.

Specific tooling
  020622Y Transmission-side oil seal punch

• Screw the threaded bar onto the base of the tool and extract the oil seal.

Specific tooling
  020622Y Transmission-side oil seal punch

Refitting

• Always use a new oil seal upon refitting
• Prepare the new oil guard by lubricating the sealing lip.
• Preassemble the oil seal with the appropriate tool by positioning the screws.
• Insert the sheath over the crankshaft.
• Insert the tool with the oil seal on the crankshaft until it comes into contact with the crankcase.
• Insert the adaptor bushing of the tool in the hole on the crankcase.

• Orientate the oil seal by inserting the bracket which is part of the appropriate tool.
• Tighten the threaded bar onto the crankshaft as far as it will go.
• Use the nut to move the base of the tool until you can see the end of the oil seal driving stroke
• Remove all the tool components following the procedure but in reverse order

CAUTION

DO NOT LUBRICATE THE KEYING SURFACE ONTO THE ENGINE CRANKCASE.

CAUTION

ORIENT THE OIL SEAL BY POSITIONING THE CHAIN HOUSING CHANNEL FACING DOWNWARDS. WHEN THE POSITION IS REACHED, DO NOT RETRACT THE OIL SEAL. FAILURE TO COMPLY WITH THIS RULE CAN CAUSE A WRONG POSITIONING OF THE OIL SEAL SHEATH.

CAUTION

FAILURE TO COMPLY WITH THIS ASSEMBLY PROCEDURE CAN SERIOUSLY DAMAGE THE ENGINE DUE TO THE WRONG TENSIONING OF THE OIL PUMP CONTROL CHAIN.

Specific tooling
  020622Y Transmission-side oil seal punch

Removal

• Undo the two clamping screws in the figure and remove the cover over the pump control sprocket.

• Block the rotation of the oil pump control pulley with a screwdriver inserted through one of its two holes.
• Remove the central screw with Belleville washer, as shown in the diagram.
• Remove the chain with the crown.
• Remove the control sprocket wheel with relative O-ring.
• Remove the oil pump by undoing the two screws in the figure.
• Remove the oil pump seal.

N.B.

IT IS ADVISABLE TO MARK THE CHAIN IN ORDER TO ENSURE THAT THE INITIAL DIRECTION OF ROTATION IS MAINTAINED.

Inspection

• Remove the two screws and the oil pump cover.
• Remove the circlip retaining the innermost rotor.
• Remove and wash the rotors thoroughly with petrol and compressed air.
• Reassemble the rotors in the pump body, keeping the two reference marks visible Replace the retainer ring.

• Check the clearance between the rotors in the position shown in the diagram using a feeler gauge.

  Measure the distance between the outer rotor and the pump body (see figure).

• Check the axial clearance of the rotors using a trued bar as shown in the figure.

Characteristic

Axial rotor clearance
Limit values admitted: 0.09 mm
Distance between the outer rotor and the pump body
Admissible limit clearance: 0.20 mm
Distance between the rotors
Admissible limit clearance: 0.12 mm

Refitting

• Check there are no signs of wear on the oil pump shaft or body.
• Check there are no signs of scoring or wear on the oil pump cover.
• If you detect non-conforming measurements or scoring, replace the faulty parts or the unit.
• Fit the pump cover in the position that permits the crankcase clamping screws to be aligned.
• Make sure the gasket is positioned properly and refit the pump on the engine crankcase. The pump can only be fitted in one position. - Tighten the screws to the prescribed torque.

• Fit the sprocket wheel with a new O-ring.
• Fit the chain.
• Fit the central screw and the cup washer. Tighten to the prescribed torque.
• Fit the oil pump cover, by tightening the two screws to the prescribed torque.

N.B.

FIT THE CUP WASHER SO THAT ITS OUTER RIM TOUCHES THE PULLEY. MAKE SURE THAT THE PUMP TURNS FREELY.

Locking torques (N*m)
Screws fixing oil pump to the crankcase 5 ÷ 6
Oil pump command sprocket screw 10 to 14
Oil pump cover screws 0.7 - 0.9

Removing the oil sump

• Remove the oil filler plug, the transmission cover, the complete driving pulley assembly with belt and the sprocket wheel, as described in the "Transmission" chapter.
• Drain the oil as described above.
• Remove the 7 screws, shown in the diagram, and the 2 rear brake fluid pipe fixing brackets.
• Remove the screw, the by-pass piston, the gasket and the centring dowels shown in the figure.

Inspecting the by-pass valve

• Check the unloaded spring length.
• Check that the small piston is not scored.
• Ensure that it slides freely on the crankcase and that it guarantees a good seal.
• If not, eliminate any impurities or replace defective parts.

Characteristic

By-pass check up: Standard length
54.2 mm

Refitting the oil sump

• Refit the by-pass piston in its housing.
• Insert the pressure-regulating spring.
• Fit a new sump seal.
• Refit the two centring dowels.
• Refit the sump, taking care to locate the spring in the appropriate recess machined into the inside of the sump.
• Refit the rear brake cable brackets and the screws in the reverse order from which they were removed.
• Tighten the screws to the prescribed torque.
• Refit the driving pulley assembly, the drive belt, the sprocket wheel and the transmission cover, as described in the "Transmission" chapter.
• When testing the lubrication system, refer to chapter "Crankcase and Crankshaft", regarding lubrication of the crankshaft and connecting rod

Locking torques (N*m)
Oil sump screws 10 to 14

See also: