RING-SNAP 8I4306 - Caterpillar

3400 Series Engines In All ApplicationsSUPPLEMENT: 04/30/90SERVICE MAGAZINE; MARCH 8, 1982; PAGE 4; "Reconditioning of Bridge Wear Seat Is Permitted; Will Prevent Bridge Replacement When Not Necessary." Disregard this article. Make reference to the article with the same title in this issue.--------------- END SUPPLEMENT ---------------During engine reconditioning or when the rocker shaft is removed, the serviceman must inspect the bridge wear seat to find if bridge can be used again. Use a dial indicator to measure the amount of wear on bridge wear seats. Make sure the contact point on the dial indicator is small enough in diameter to get an accurate measurement. See Illustration 1 for typical wear.
Use the bridge again if the wear is 0.13 mm (0.005") or less. See Illustration 2. When the wear seat is worn more than 0.13 mm (0.005") the worn surface of the seat can be ground flat. The maximum amount material that can be removed is 0.38 mm (0.015"). If the seat can not be made flat, make replacement of the bridge. Reconditioning of the wear can only be done once.
Illustration 1. Typical wear on bridge wear seat.
Illustration 2. Dimensions for reconditioning.