Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2002 Jeep TJ (CANADA) L6-4.0LFACTORY OEM SERVICE PROCEDURE
Service Specifications
CYLINDER HEAD
Combustion Chamber 55.22 to 58.22 cc (3.37 to 3.55 cu. inch)
Valve Guide I.D. (Integral) 7.95 to 7.97 mm (0.313 to 0.314 inch)
Valve Stem-to-Guide Clearance 0.025 to 0.076 mm (0.001 to 0.003 inch)
Valve Seat Angle
Intake 44.50
Exhaust 44.50
Valve Seat Width 1.02 to 1.52 mm (0.040 to 0.060 inch)
Valve Seat Runout 0.064 mm (0.0025 inch)
Flatness 0.03 mm per 25 mm (0.001 in. per 1 inch) 0.05 mm per 152 mm (0.002 in. per 6 inch)
Flatness Max. 0.20 mm - max. for total length (0.008 in. max. for total length)
VALVES
Valve Length (Overall)
Intake 122.479 to 122.860 mm (4.822 to 4.837 inch)
Exhaust 122.860 to 123.241 mm (4.837 to 4.852 inch)
Valve Stem Diameter 7.899 to 7.925 mm (0.311 to 0.312 inch)
Stem-to-Guide Clearance 0.025 to 0.076 mm (0.001 to 0.003 inch)
Valve Head Diameter
Intake 48.387 to 48.641 mm (1.905 to 1.915 inch)
Exhaust 37.973 to 38.227 mm (1.495 to 1.505 inch)
Valve Face Angle
Intake 46.50
Exhaust 46.50
Tip Refinishing (Max. Allowable) 0.25 mm (0.010 inch)
VALVE SPRINGS
Free Length (Approx.) 47.65 mm (1.876 inch)
Spring Load
Valve Closed 316 to 351 N @ 41.656 mm (71 to 79 lbs. @ 1.64 inch)
Valve Open 898.6 to 969.7 N @ 30.89 mm (202 to 218 lbs @ 1.216 inch)
Inside Diameter 21.0 mm to 21.51 mm (0.827 to 0.847 inch)
Installed Height 41.656 mm (1.64 inch)
Combustion Chamber 55.22 to 58.22 cc (3.37 to 3.55 cu. inch)
Valve Guide I.D. (Integral) 7.95 to 7.97 mm (0.313 to 0.314 inch)
Valve Stem-to-Guide Clearance 0.025 to 0.076 mm (0.001 to 0.003 inch)
Valve Seat Angle
Intake 44.50
Exhaust 44.50
Valve Seat Width 1.02 to 1.52 mm (0.040 to 0.060 inch)
Valve Seat Runout 0.064 mm (0.0025 inch)
Flatness 0.03 mm per 25 mm (0.001 in. per 1 inch) 0.05 mm per 152 mm (0.002 in. per 6 inch)
Flatness Max. 0.20 mm - max. for total length (0.008 in. max. for total length)
VALVES
Valve Length (Overall)
Intake 122.479 to 122.860 mm (4.822 to 4.837 inch)
Exhaust 122.860 to 123.241 mm (4.837 to 4.852 inch)
Valve Stem Diameter 7.899 to 7.925 mm (0.311 to 0.312 inch)
Stem-to-Guide Clearance 0.025 to 0.076 mm (0.001 to 0.003 inch)
Valve Head Diameter
Intake 48.387 to 48.641 mm (1.905 to 1.915 inch)
Exhaust 37.973 to 38.227 mm (1.495 to 1.505 inch)
Valve Face Angle
Intake 46.50
Exhaust 46.50
Tip Refinishing (Max. Allowable) 0.25 mm (0.010 inch)
VALVE SPRINGS
Free Length (Approx.) 47.65 mm (1.876 inch)
Spring Load
Valve Closed 316 to 351 N @ 41.656 mm (71 to 79 lbs. @ 1.64 inch)
Valve Open 898.6 to 969.7 N @ 30.89 mm (202 to 218 lbs @ 1.216 inch)
Inside Diameter 21.0 mm to 21.51 mm (0.827 to 0.847 inch)
Installed Height 41.656 mm (1.64 inch)
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.