BEARING 9S8951 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified.Problem
Illustration 1 g06287624
Typical view of seal misalignment failure
(A) Bore
(B) Seal
Illustration 2 g06287625
Typical view of sleeve misalignment failure
(A) Bore
(C) Sleeve 436-1478 Crankshaft Seal and 436-1479 Crankshaft Seal may fail due to axial misalignment between the seal and sleeve, or due to seal cocking during installation.Solution
Caterpillar is aware of this problem and is recommending the following interim corrective solution.
Illustration 3 g06287629
Typical view of seal installed using 447-6483 Driver Assembly
Illustration 4 g06287626
Typical view of seal installed using FT-3549 Driver Assembly
(D) 0.18 mm (0.007 inch)A new seal driver is used with 436-1478 Crankshaft Seal and 436-1479 Crankshaft Seal. FT-3549 driver replaces 447-6483 Driver Assembly in 484-7863 Tool As during installation of 436-1478 Crankshaft Seal and 436-1479 Crankshaft Seal only. This increases the installed clearance between dust exclusion feature inside the seal, and the vertical portion of the sleeve which eliminates fouling of seal during operation in certain environments.Refer to Table 1 for seal and sleeve cocking limits for installed seals.
Table 1
Maximum Target
Seal to bore radial limit 0.5 mm (0.02 inch) Less than 0.20 mm (0.007 inch)
Sleeve to shaft radial limit 0.5 mm (0.02 inch) Less than 0.20 mm (0.007 inch) Note: Engineering drawing print for FT-3549 driver can be found in the following website:https://dealer.cat.com/en/ps/service-tools.html
Note: If crankshaft seal failures are experienced by dealers, contact Dealer Solution Network (DSN) to provide details of the failure, and Send it Back information if requested.