About the CAT 3116 Engine
The Caterpillar 3116 is a 6-cylinder, 6.6-liter turbocharged diesel engine that powered a wide range of mid-size Caterpillar equipment from the late 1980s through the early 2000s, including 315, 320, and 322 series excavators, 950F and 960F wheel loaders, and numerous on-highway trucks. It remains a common engine in the field due to the sheer number of units produced and the longevity of the equipment it powered.
Common Failure Points
The 3116 is generally a reliable engine, but several wear points are well-known. The cylinder sleeves tend to be the first major wear item — the 3116 uses wet sleeves that can develop cavitation erosion on the outside surface over high hours. The fuel injection pump is another common failure point after 10,000+ hours. Valve train components, particularly the rocker arms and camshaft lobes, also wear more quickly than in some competitive engines of the era.
In-Frame vs. Complete Rebuild
An in-frame rebuild replaces the rings, bearings, cylinder sleeves, and gaskets without removing the engine from the machine or splitting the block. This is appropriate when the crankshaft and camshaft are within tolerance and the block is not cracked. A complete out-of-frame rebuild is required when the crank needs grinding, the block needs boring, or there is structural damage to the block or main bearing saddles.
Parts Required for a Standard In-Frame
A typical 3116 in-frame rebuild requires: a complete overhaul gasket set, 6 cylinder sleeve and piston assemblies, connecting rod bearings, main bearings, a thrust washer set, a complete valve train kit, and timing chain and gear set. We stock all of these components individually and as complete rebuild kits — see our 3116 parts category for current pricing and availability.