Jeep Head Bolt Torque Specs
by William Boyce
Each Jeep engine has unique head bolt torque specifications. Head bolts hold the engine head onto the engine block and resist the force of engine compression. There are two key pieces of information with each torque specification: the sequential order for tightening the set of bolts and the amount to tighten the bolts at each tightening step. There may be eight, 10 or 14 head bolts on a Jeep engine depending on the number of cylinders and the displacement.
2.5 L Four Cylinder Engine
There are two rows of five head bolts on the 2.5-liter four-cylinder engine. From the front to the back, the driver side bolts are numbered 8, 5, 1, 4, 7, while the passenger side bolts are numbered 10, 6, 2, 3, 9.
From 1984 to 1987, the bolts are tightened in these steps: first to 25 ft.-lb., second to 50 ft.-lb., third (bolt 8) is tightened to 75 ft.-lb., and fourth, all other bolts are tightened to 85 ft.-lb. From 1988 and on, the bolts are tightened in these steps: first to 22 ft.-lb., second to 45 ft.-lb., third, bolt 8 is tightened to 100 ft.-lb., and all other bolts to 110 ft.-lb.
Inline Six-Cylinder Engines
There are two rows of seven head bolts on the inline six-cylinder engine. From front to back on the driver's side, they are numbered 11, 7, 3, 2, 6, 10, 14, and on the passenger side, they are numbered 12, 8, 4, 1, 5, 9, 13. Bolts are tightened in these steps: first to 22 ft.-lb., second to 45 ft.-lb., third to 45 ft-lb. again, fourth (bolt 11) to 100 ft.-lb., and fifth, all other bolts to 110 ft.-lb.
V6 Engine
There are two rows of four head bolts on each bank of the V6 engine. Each bank is tightened using the same steps and specifications. From front to back on the driver's side. they are numbered 7, 3, 2, 6, and on the passenger side they are numbered 8, 4, 1, 5. Bolts are tightened in one step: first to 70 ft.-lb.
2.4-liter Four-Cylinder Engine
There are two rows of five head bolts on the 2.4-liter four-cylinder engine. From the front to the back, the driver side bolts are numbered 9, 5, 1, 5, 8 and the passenger side is numbered 10, 6, 2, 3, 7. The bolts are tightened in these steps: first to 25 ft.-lb., second to 50 ft.-lb., third to 50 ft.-lb. again, and fourth, tighten all bolts an additional 90 degrees.
References
- "Jeep Wrangler Automotive Repair Manual"; Mike Stubblefield and John H Haynes; 2004
- "Jeep Cherokee and Comanche Automotive Repair Manual"; Bob Henderson and John H Haynes; 1991
Writer Bio
William Boyce started writing professionally in 2009. His work has appeared on FreePress.net and his own blog. Boyce was a registered professional forester in central British Columbia for 24 years. He has a Bachelor of Science in forestry from the University of British Columbia.
