Valve Lash & Overhead PACCAR MX-13 Verified Factory Specs

PACCAR MX-13 Valve Lash Specs & Overhead Adjustment (Cold Engine)

Factory OEM valve lash clearances, feeler gauge sizes, Jake brake slave setting, and overhead adjustment procedure for PACCAR MX-13 diesel engines.

Selected Heavy Diesel Engine

Engine:PACCAR MX-13 (EPA10 / EPA13 / EPA17 / EPA21)

Displacement:12.9L

Firing Order:1-5-3-6-2-4

Locknut Torque:30 ft-lbs

Intake Valve Lash (Cold)

0.016 in

Feeler Blade: .016 in (0.40 mm)

Exhaust Valve Lash (Cold)

0.028 in

Feeler Blade: .028 in (0.70 mm)

Engine Brake (Jake) Lash

0.055 in

Feeler Blade: .055 in (1.40 mm)

2-Turn Crankshaft Adjustment Protocol

Firing Order: 1-5-3-6-2-4

Select engine stroke position below to highlight exact cylinders, valves, and injectors ready for adjustment:

Crankshaft Timing Pin Position

Rotate crankshaft until timing pin locates TDC Compression Cylinder 1

Intake Valves Ready

Cylinders: N/A

Exhaust Valves Ready

Cylinders: N/A

Engine Brakes / Injectors Ready

Cylinders: N/A

Locknut Torque: 30 ft-lbs (41 N·m)

Source: PACCAR Engine Service Manual MX-13 EPA17 (Valve Clearance & Cylinder Head Assembly)

PACCAR MX-13 Cold Valve Clearance Standards

Overhead adjustment must strictly be performed with coolant temperature below 140°F (60°C):

INTAKE VALVES (COLD):

0.016 in (0.40 mm)

Feeler gauge: Smooth sliding friction drag.

EXHAUST VALVES (COLD):

0.028 in (0.70 mm)

Feeler gauge: Smooth sliding friction drag.

Engine Brake (Jake) Slave Lash & Injector Preload Dimensions

Engine Brake Slave Clearance: 0.047 in (1.20 mm)

Injector Preload / Height: Unit pump electronic control

2-Turn Setting Order: Crankshaft timing pin into flywheel; check cylinder 1 overlap vs firing.

Locknut Torque & Maintenance Precautions

Always hold the valve adjustment screw stationary with a screwdriver or hex key while torquing the jam locknut to factory specification. Re-check clearance with feeler blade after final tightening to ensure screw did not turn.

Frequently Asked Questions & OEM Service Guidelines

Verified answers according to official factory service literature and heavy-duty maintenance procedures:

Q: What is the cold valve lash setting on a PACCAR MX13?

Intake valve clearance is 0.016 inches (0.40 mm) and exhaust valve clearance is 0.031 inches (0.80 mm), set using official PACCAR engine barring tool 1453158.

Q: What is the engine oil capacity of a PACCAR MX13 EPA17 engine?

The oil capacity with filter is 42.0 US quarts (10.5 gallons / 39.7 liters) for composite oil pans, and 44.0 quarts (11.0 gallons) for cast aluminum pans.

Related Heavy Diesel Engineering Tools

Cross-reference other factory specifications and diagnostic tools for commercial diesel engines:

Pillar 3 →

Valve Lash & Overhead

Intake, exhaust, & Jake brake clearances.

Pillar 1 →

Oil & Coolant Sump

Standard vs deep pan fill volumes.

Pillar 4 →

Head Bolt Torque

Torque-to-yield angle stages & sequences.

Pillar 2 →

SPN Fault Code Lookup

J1939 fault diagnostics & sensor pins.

Technical Reference Citation: PACCAR Engine Service Manual MX-13 EPA17 (Valve Clearance & Cylinder Head Assembly)

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