Usage:
3406 And 3408 Truck Engines So Equipped
Reference: Service Magazine, September 14, 1981, Pages 6 and 7. The article "Changes To BrakeSaver Groups Give Longer Service Life," told about the use of several new parts in the BrakeSaver group on 3406 and 3408 Truck Engines. At that time, a new sleeve and dowel were released. The new dowel was larger in diameter to decrease the wear between it and the sleeve. The sleeve that was released at that time was machined with two holes, one each for the small and large dowels.
Description of Change: Reports now show that the dowel hole which is not used (in either application) permits enough oil leakage into the area between the high pressure seal ring and the lip seal to cause a small pressure increase in that area. This can increase the wear on the lip seal.
For this reason, a new sleeve is now used, which has a hole for the larger dowel only. The original sleeve, which has a hole for the small dowel only, is again available for parts service.
Adaptable As: The new 2W4838 Sleeve is a direct replacement for the former 9N6490 Sleeve in applications where the 7F8817 Dowel (large) is used. The original 9N1850 Sleeve can be used for parts service in applications where the 5B582 Dowel (small) was used. The 9N6490 Sleeve has been canceled.
Location of sleeve and dowel in BrakeSaver group.