Overhaul (Top End) - Perkins 4016-61 TRG Operation And Maintenance Manual

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Maintenance Section

Overhaul (Top End)

• An increase of oil consumption
• An increase of crankcase blowby
• A decrease and variation of cylinder compression
Other factors should be considered for determining a
major overhaul:
• The service hours of the engine
• The wear metal analysis of the lube oil
• An increase in the levels of noise and vibration
An increase of wear metals in the lube oil indicates
that the bearings and the surfaces that wear may
need to be serviced. An increase in the levels of
noise and vibration indicates that rotating parts
require service.
Note: It is possible for oil analysis to indicate a
decrease of wear metals in the lube oil. The cylinder
liners may be worn so that polishing of the bore
occurs. Also, the increased use of lube oil will dilute
the wear metals.
Monitor the engine as the engine accumulates
service hours. Consult Perkins Engines Stafford
about scheduling a major overhaul.
Perkins recommends that at 7500 hours for prime
power and base load applications or 5 years for
standby applications, the following components
should be removed from the engine:
• Piston assembly
• Piston rings
• Cylinder liner
• Connecting rod bearings
Note: One cylinder from "A Bank" should be selected
to have the components removed. Another cylinder
from "B Bank" should be selected to have the
components removed.
Contact your Perkins distributor or Perkins dealer for
more information. An inspection of the components
by the Perkins distributor or Perkins dealer can help
to determine when a major overhaul is required as
well as the other factors.
Note: The driven equipment may also require service
when the engine is overhauled. Refer to the literature
that is provided by the OEM of the driven equipment.
Major Overhaul Information
During a major overhaul, all the bearings, seals,
joints, and components that wear should be
disassembled. The parts should be cleaned. The
parts should then be inspected. If necessary, the
parts should be replaced. The crankshaft should be
inspected and measured for wear. The crankshaft
may require regrinding. Alternatively, the crankshaft
may be replaced.
Inspecting Components
Inspect the following components during a major
overhaul.
• Engine-mounted aftercoolers
• Camshafts
• Camshaft followers
• Connecting rods and bearings
• Crankshaft and bearings
• Gear train
• Inlet air piping
• Oil cooler
• Pistons and rings
• Cylinder liners
Replace the crankshaft vibration damper.
Overhaul (Top End)
Scheduling a Top End Overhaul
Top end overhauls should be scheduled depending
on valve recession. Record the valve depth at each
service and then calculate the valve recession. This
measurement provides an accurate indication of the
rate of valve wear. This measurement can be used to
predict when a cylinder head must be replaced.
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