Series 638 – Section 1.21 Rear Main Seal (Flywheel Housing Removed)

Section 1.21
Rear Main Seal (Flywheel Housing Removed)

The Turbotronic 638 rear main seal prevents the leaking of lubricating oil from the engine and is an integral part of the rear main bearing carrier assembly (see Figure "Location of Rear Main Seal" ).‪

1.Rear Main Bearing‪	5.Rear Oil Seal‪
2.Thrust Washer‪	6.Seal Ring‪
3.Rear Carrier Housing‪	7.Stud‪
4.Piston Jet Valve‪	8.Spring PIn‪

Figure 1. Location of Rear Main Seal

Section 1.21.1
Replacement of Rear Main Seal

To determine if replacement of the rear main seal carrier is necessary, perform the following procedure. See Figure "Flowchart for Replacement of Rear Main Seal" .‪

Figure 2. Flowchart for Replacement of Rear Main Seal

Section 1.21.2
Removal of Rear Main Seal

Remove the rear main seal as follows:‪

1. Remove flywheel housing. Refer to "1.17.2 Removal of Flywheel Housing" .
2. Remove rear crankshaft carrier assembly from the cylinder block.
3. Remove rear main seal from crankshaft carrier assembly. See Figure "Flowchart for Replacement of Rear Main Seal" .

Section 1.21.2.1
Inspection of Rear Main Seal

Inspect the rear main seal components as follows:‪

1. Visually check the spacer plate for nicks and burrs on the sealing surface.
   1. If the spacer plate has nicks or burrs, replace the component. Refer to "1.21.3 Installation of Rear Main Seal" .
   2. If the spacer plate has no nicks or burrs, proceed with step 2 of inspection.
2. Visually check the spacer plate inside thrust bearing wear surface for nicks or damage.
   1. If the spacer plate inside thrust bearing wear surface has been nicked or is damaged, replace the component. Refer to "1.21.3 Installation of Rear Main Seal" .
   2. If the spacer plate inside thrust bearing wear surface has not been nicked or damaged, reuse the component. Refer to "1.21.3 Installation of Rear Main Seal" .

Section 1.21.3
Installation of Rear Main Seal

Install the rear main seal as follows:‪

1. Install the rear main seal. See Figure "Rear Main Seal Location" .
   

   1.Rear Main Bearing‪	5.Rear Main Seal‪
   2.Thrust Washer‪	6.Seal Ring‪
   3.Rear Carrier Housing‪	7.Stud‪
   4.Piston Jet Valve‪	8.Spring PIn‪

   Figure 3. Rear Main Seal Location

2. Install the crankshaft carrier assembly.
3. Install the flywheel housing. Refer to "1.17.3 Installation of Flywheel Housing" .
4. Run the engine to verify repair.