Usage:
3406, 3408 Truck Engine
- SUPPLEMENT: 11/07/84
TRUCK ENGINE NEWS, NOVEMBER 23, 1983, PAGE 8. The article "New Connecting Rod And Main Bearings Used" tells about the use of copper bonded bearings. The in effect serial numbers for these bearings in 3400 Series Engines are now available.
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Reference: The Truck Engine News, April 13, 1983 article "New Connecting Rod Bearings Used " told of the use of new connecting rod bearings for 3408 Truck Engines. This new article has some of the information from the earlier article plus some additional information. Make a reference in the earlier article to this new article.
Description of Change: New connecting rod and crankshaft main bearings are now used in the rod and piston groups and crankshaft groups on 3406 and 3408 Truck 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.
Adaptable As: The new bearings are a direct replacement for the former bearings as shown in the chart.