Overspeed Guidance for 3500 and C175 Machine Engines{1000, 1915, 7410, 7427, 7490} Caterpillar

Overspeed Guidance for 3500 and C175 Machine Engines{1000, 1915, 7410, 7427, 7490}

Usage:

793B 1HL

Engine: All 3500 Engines All C175 Engines

Introduction

"Overspeed" is a condition where the engine speed reaches an RPM higher than the intended operating range.

Although systems are in place to prevent "Overspeed" events, in some scenarios "Overspeed" events can occur and can have detrimental impact on engine life, depending on frequency and severity.

The engine-specific charts suggest the actions to take for your product. Refer to engine-specific publications for details on each inspection.

This publication serves only as a general guide. Technicians should use their best judgment to evaluate each scenario.

3500 Overspeed Chart

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Table 1
RPM Range	2200 to 2399	2400 to 2599		2600 to 2799	2800 to 2999	3000 or More
Event Count	255 or More	1 to 24	25 or More	1 or More	1 or More	1 or More
Cams and Lifters	Investigate cause and change operations	Investigate cause and change operations	Inspect			Inspect all components or remove engine If removing engine, notify dealer CRC of the "Overspeed" event to prompt additional component inspection
Valves and Pistons			Investigate cause and change operations		Inspect
Rod Eye Bushings			Investigate cause and change operations		Investigate cause and change operations
Rod Bearings			Inspect rod bearings

C175 Overspeed Chart

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Table 2
RPM Range	2200 to 2399	2400 to 2599		2600 to 2699	2700 or More
Event Count	1 or More	1 to 25	25 or More	1 or More	1 or More
Cams and Lifters	Investigate cause and change operations	Investigate cause and change operations	Inspect	Inspect all components or remove engine If removing engine, notify dealer CRC of the "Overspeed" event to prompt additional component inspection	Remove and replace engine Notify dealer CRC of the "Overspeed" event to prompt additional component inspection
Valves and Pistons
Rod Eye Bushings
Rod Bearings

3500 Engine Reference Publications

Reuse And Salvage Guidelines, SEBF8002, "Visual Inspection of Valves, Valve Springs, and Valve Bridges"
Reuse And Salvage Guidelines, SEBF8009, "Visual Inspection of Main Bearings and Connecting Rod Bearings"
Reuse And Salvage Guidelines, SEBF8049, "Visual Inspection of the Piston"
Reuse And Salvage Guidelines, SEBF8063, "Visual Inspection of Connecting Rods"
Reuse And Salvage Guidelines, SEBF8067, "Inspection of Slipper Followers and Roller Lifters"
Reuse And Salvage Guidelines, SEBF8146, "Visual Inspection of Camshafts"

C175 Engine Reference Publications

Reuse And Salvage Guidelines, SEBF8009, "Visual Inspection of Main Bearings and Connecting Rod Bearings"
Reuse And Salvage Guidelines, SEBF8049, "Visual Inspection of the Piston"
Reuse And Salvage Guidelines, SEBF8063, "Visual Inspection of Connecting Rods"
Reuse And Salvage Guidelines, SEBF8146, "Visual Inspection of Camshafts"
Reuse And Salvage Guidelines, SEBF9186, "Specifications and Visual Inspection of Rocker Arms, Rocker Arm Shafts, Bridge Assemblies, and Lifters for C175 Engines"