IDLER GP-TRACK 2061895 - Caterpillar

All 3304 And 3306 EnginesSUPPLEMENT: 09/00/85ENGINE NEWS, APRIL 11, 1984, PAGE 5.The article "New Connecting Rod And Main Bearings Used" contains a wrong conversion. In the chart, in the Size column under the heading Main Bearings, put a mark through the last two 0.51 mm (.030") O.S. conversions. The correct conversion should read 0.51 mm (.020") O.S.
--------------- END SUPPLEMENT ---------------Description of Change: New connecting rods and main bearings (Standard Sizes Only) are now used in the rod and piston groups and the crankshaft groups on 3304 and 3306 Engines. The new bearings have a different design, which uses a copper material to bond (fasten) the lead-tin overlay to the aluminum bearing material. After the lead-tin overlay is worn away, this copper bond will decrease scuffing during lack of lubrication conditions. Cold starts, failure to prelube after oil changes, and low oil levels will all result in a lack of lubrication condition. Remember that during normal engine operation the lead-tin overlay will be worn away in some areas before the overhaul time.
Formerly, a nickel material was used to bond the overlay to the aluminum bearing material.
In the future, the undersize and oversize bearings will be of the copper bond design, but their part numbers will not change. Currently, these bearings are the nickel bond design.
Adaptable As: The new and former bearings are shown in the chart. Only the part numbers for the standard sizes have changed.