PACCAR MX-13 Head Bolt Torque Specs & Torque-Turn Sequence
Factory OEM cylinder head bolt torque specifications, torque-turn angle degree stages & tightening patterns for PACCAR MX-13 diesel engines.
Step-by-Step Torquing Stages (Follow in Numbered Sequence)
Primary: Foot-Pounds⚠️ Master Technician Tip: Clean and blow out all cylinder block bolt blind holes with compressed air. Lightly lubricate bolt threads and under-head flanges with clean engine oil before installation.
OEM Specification Source: PACCAR Engine Service Manual MX-13 EPA17 (Valve Clearance & Cylinder Head Assembly)
PACCAR MX-13 (EPA10 / EPA13 / EPA17 / EPA21) 38-Bolt Cylinder Head Tightening Order
PACCAR MX-13 Cylinder Head Tightening Procedure & Angle Stages
Follow official factory numbered sequence tightening progressively from center bolts outward:
- Stage 1: Torque all M16 head bolts to 110 ft-lbs (150 N·m) in numbered spiral sequence.
- Stage 2: Torque all M16 head bolts to 185 ft-lbs (250 N·m) in numbered sequence.
- Stage 3 (Torque Angle 1): Turn all M16 head bolts 60 degrees clockwise in sequence.
- Stage 4 (Torque Angle 2): Turn all M16 head bolts an additional 60 degrees clockwise (120° total angular yield).
PACCAR MX-13 Critical Secondary Engine Fastener Torque Specifications
Overhaul and rebuild torque specifications for major rotating assembly and valvetrain fasteners:
| Component / Fastener Location | Thread Size | Imperial Torque (lb-ft) | Metric Torque (N·m) | Procedural Notes |
|---|---|---|---|---|
| Flywheel-to-Crankshaft Bolts | M16 | 185 lb-ft + 60° | 250 N·m + 60° | Torque-turn torx bolts |
| Connecting Rod Cap Bolts | M14 | 65 lb-ft + 60° | 88 N·m + 60° | Fractured-split rod caps |
| Camshaft Bearing Cap Bolts | M10 | 35 lb-ft + 45° | 47 N·m + 45° | Check cam journal clearance |
| Rocker Shaft Support Bolts | M12 | 70 lb-ft + 60° | 95 N·m + 60° | Lubricate shaft bores |
| Exhaust Manifold Stud Nuts | M10 | 40 lb-ft | 54 N·m | Spiral tightening order |
OEM Fastener Invariants, Thread Chasing & Reusability Standards
PACCAR MX-13 uses Compacted Graphite Iron (CGI) block casting. Ensure all fastener tap holes are clean and dry to prevent hydraulic block fracturing.
Always lubricate fastener threads and washer contact faces with clean SAE 15W-40 engine oil before tightening. Never torque cylinder head fasteners dry.
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
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