Valve Lash & Overhead PACCAR MX-13 Verified Factory Specs

PACCAR MX-13 Valve Lash & Engine Brake Decompression Specs

Factory OEM cold valve lash adjustment specifications, feeler gauge sizes, and TDC cylinder firing order steps for PACCAR MX-13 commercial diesel engines.

Selected Heavy Diesel Engine

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)

Cylinder Adjustment Stepper (Firing Order: 1-5-3-6-2-4)

Click Step 1 or Step 2 to highlight which valves to set based on crankshaft timing mark.

Step 1 of 2: Cylinder 1 at Top Dead Center (TDC)

Rotate crankshaft until timing pin locates TDC Compression Cylinder 1

Valves to Adjust in this Position:Cylinder 1 Intake & Exhaust, Cylinder 2 Intake, Cylinder 3 Exhaust, Cylinder 4 Intake

Engine Brake (Jake) & Injector Settings:Cylinder 1 & Cylinder 3 Engine Brake Decompression Valves (.055 in / 1.40 mm)

Rocker Arm Lock Nut Torque: 30 ft-lbs (41 N·m)

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

PACCAR MX-13 Valve & Decompression Brake Adjustment

The PACCAR MX-13 compacted graphite iron (CGI) engine uses a pushrod-activated valve train with overhead camshaft. Clearance must be verified cold:

Timing Pin at TDC Compression Cylinder 1

Intake Valves: Cylinder 1, Cylinder 2, Cylinder 4 (.016 in / 0.40 mm)
Exhaust Valves: Cylinder 1, Cylinder 3 (.028 in / 0.70 mm)
Decompression Brake: Cylinder 1 & Cylinder 3 (.055 in / 1.40 mm)

Timing Pin at TDC Compression Cylinder 6 (Rotate 360°)

Intake Valves: Cylinder 6, Cylinder 5, Cylinder 3 (.016 in / 0.40 mm)
Exhaust Valves: Cylinder 6, Cylinder 4, Cylinder 2 (.028 in / 0.70 mm)
Decompression Brake: Cylinder 6 & Cylinder 4 (.055 in / 1.40 mm)

Locknut Torque: Torque valve adjustment locknuts to 30 ft-lbs (40 N·m). Re-check feeler blade drag after locking.

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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