STEM AS-VALVE 6L7148 - Caterpillar

D343 Industrial and Marine Engines;
1693 Truck Engines;
G343 Gas EnginesSUPPLEMENT: 08/21/78SERVICE MAGAZINE, JULY 10, 1978, PAGE 5.Two corrections must be made to the article "New Flange-Type Seal Used At Rear Of Crankshaft". First, change the subtitle to read: "D343 Industrial and Marine Engines; 1693 Truck Engines; G343 Gas Engines". The new seal is not adaptable to the engines used in machine models. Second, a wrong part number is given in the installation procedure. Change Step 1 to read: 1. Remove the 5S3899 Baffle and the old seal.
--------------- END SUPPLEMENT ---------------Description of Change: A new crankshaft rear seal for the above models has a flange with holes so it can be fastened with bolts to the engine. With this design, the former baffle is not needed and it is not necessary to use a press to install the seal in the baffle. This makes seal installation easier, and will prevent damage which was possible during assembly and installation of the former seal and baffle. A back-up ring is used between the bolt heads and the seal flange for good flange support. Also, a new gasket is used under the seal flange. The new gasket has better sealing characteristics than the former gasket.
Location of parts.With the new rear seal, a wear ring is now used on the crankshaft gear hub. This permits the repair of a worn seal surface without installation of a new gear.
Adaptable As: The new parts, used together, are a direct replacement for the former parts. INSTALLATION: Use the procedure that follows to install the new parts: 1. Remove the 5S3899 Baffle and the old seal.2. Clean the sealing surface of the crankshaft gear.3. Put Loctite on this surface before the sleeve is installed. If grooves of .005" (1.27 mm) or deeper are present in the gear surface, use RTV Sealing Compound.
Install the 9N3776 Sleeve (see the Illustration) with a 5P7294 Installer, 9S8870 Locator, 9S8858 Nut and three 618718 Bolts.
If the installer is not available, heat the sleeve to 400°F (204°C) in oil. Then install the sleeve. Tighten the bolts opposite each other, in sequence, one half turn at a time.5. Remove the flywheel.6. Check the sleeve for burrs and remove if necessary. Put engine oil on the sleeve and seal lip.7. Install the 9N3281 Gasket between the flywheel housing and seal flange. Install the 9N3775 Seal.8. Install the 9N1398 Ring with six 1T720 Bolts. It is important that you use these bolts so the bolt heads do not interfere (make contact) with the flywheel. Tighten the bolts to 32 3 lb ft (43 4 N m).9. Install the flywheel.10. Run the engine for 20 minutes at low idle and check for leaks.