RACE 3S8021 - Caterpillar

Engine C27 Engines C32 EnginesDescription Of Change: New O-ring seal is now used on certain Cat® Machine Engines. The new o-ring seal is larger than the existing seal, creating more compression to help prevent oil leaks.Adaptable To: New O-ring seal is adaptable to the products within the listed serial numbers, and is effective with all products after the listed serial numbers.To identify the oil leakage, refer to the below information:
Illustration 1 g06258587
Image shows oil leaking through crankshaft gear bolt holes
Leaks of the existing o-ring are commonly misdiagnosed as crankshaft seal leaks. Leaks of the crankshaft gear o-ring seal can be identified by visual inspection of the crankshaft gear after the removal of the flywheel.
The presence of oil inside the flywheel through bolt holes of the crankshaft gear is indicative of a leak of the crankshaft gear o-ring seal or crankshaft wear sleeve. Refer to Illustration 1 for oil leaking through crankshaft gear bolt holes.
The presence of oil in the through bolt holes requires that the flywheel housing is removed to access the crankshaft gear o-ring seal and crankshaft wear sleeve.
If the gear is removed, replace existing 6V-3319 O-Ring Seal with the new 502-4034 O-Ring Seal. Also replace 4N-0848 Wear Sleeve with the same part number ( 4N-0848 Wear Sleeve) on the rear end of the crankshaft.Note: Loctite 620 sealant is required between the crankshaft and crankshaft wear sleeve interface.
Illustration 2 g06258589
crankshaft wear sleeve installed on the rear end of the crankshaft
Ensure that excess sealant is removed after the wear sleeve is installed. Refer to Illustration 2 shows the crankshaft wear sleeve installed on rear end of the crankshaft.