Torque Specifications For Detroit Diesel 71 Series Inline (Not Including 2 Cylinder)

June 9, 2023

Torque Specifications for Detroit Diesel 71 Inline Engines (Excluding 271): A Complete Guide

Detroit Diesel’s 71 series inline engines have been a staple in various industries, known for their rugged performance and reliability. Whether used in marine, industrial, or commercial applications, ensuring proper torque specifications during maintenance and repairs is essential for optimal engine performance and longevity. In this guide, we provide the crucial torque specs for Detroit Diesel 71 inline engines (excluding the 271), helping you keep these workhorse engines running efficiently.

	Torque Specifications For Detroit Diesel Series 71 (Inline Except 2 Cylinder)
Thread Size (in.)	Description	Torque Specifications
Thread Size (in.)	Description	lb-ft	N-m
1/4-20	Standard Torque Specification	7-9	9-12
	Bolt-Injector Control Shaft Bracket	10-12	14-16
	Bolt-Cam Follower Guide	12-16	16-22
1/4-28	Standard Torque Specification	96-120	130-163
1/4-28	Screw-Inj. Rack Control Lever	24-36	33-49
5/16-18	Standard Torque Specification	156-204	212-277
	Bolt-Oil Pan (Cast) – Hard Gasket	13-21	18-28
	Bolt-Oil Pan (Low Pan or In Aluminum F/W Hsg. & Front Cover)	10-12	14-16
5/16-24	Standard Torque Specification	15-19	20-26
	Nut-Lock-Push Rod	15-19	20-26
	Bolt-Blower Drive Coupling Rotor Gear	20-25	27-34
	Bolt-Blower Rotor Gear Hub	25-30	34-41
	Nut-Lock Valve Bridge Adj. Screw	20-25	27-34
7/16-14	Standard Torque Specification	46-50	62-68
	Bolt-Tach. Drive	30-35	41-47
	Bolt-Lifter Bracket	55-60	75-81
	Bolt-Valve Bridge Guide (Nylon-Insert)	46-50	62-68
	Bolt-Flywheel Housing Large Hole Cover	30-35	41-47
	Bolt-Blower to Block	55-60	75-81
7/16-20	Standard Torque Specification	57-61	77-83
	Connector-Fuel (Steel Washer)	40-45	54-61
	Nut-Exhaust Manifold	30-35	41-47
	Nut-Connecting Rod	60-70	81-95
	Connector- Fuel (Nylon Insert)	30-35	41-47
	Nut-Connecting Rod	60-70	81-95
	Bolt-Connecting Rod to Pin	55-60	75-81
3/8-16	Standard Torque Specification	30-35	41-47
	Bolt-Camshaft & Seal End Bearing	35-40	47-54
	Bolt-Flywheel Hsg to Idler Gear & Dummy	40-45	54-61
	Bolt-Air Box Cover	10-15	14-20
	Bolt-Rocker Cover Hold-Down Special 12-Point	15-20	20-27
	Bolt-Injector Clamp	20-25	27-34
	Bolt-Oil Pan	10-20	14-27
3/8-24	Standard Torque Specification	35-39	47-53
	Bolt-Accessory Drive to Balance Gear (Steel Disc)	45-50	61-68
	Bolt-Lower Front Cover	25-30	34-41
	Nut-Water Manifold	20-25	27-34
	Bolt-Balance Weight to Hub	25-30	34-41
	Bolt-Balance Weight to Timing Gear	25-30	34-41
	Bolt & Nut-Blower Drive Gear	25-30	34-41
	Nut-Exhaust Outlet Manifold Flange	20-25	27-34
	Nut-Fuel Jumper Line O Ring	13-17	18-23
	Nut-Fuel Jumper Line Flared	11-13	15-18
	Nut-Injector Clamp	20-25	27-34
1/2-13	Standard Torque Specification	71-75	96-102
	Bolt-Flywheel Housing	90-100	122-136
	Bolt-Idler Gear Hub and Dummy Hub	80-90	108-122
	Bolt-Tach. Drive Cover	30-35	41-47
	Bolt-Engine Mtg Brkt to Frt Cover	90-100	122-136
	Bolt-Front Cover (Crankshaft)	80-90	108-122
	Bolt-Flywheel Housing Large Hole Cover	30-35	41-47
	Bolt-Rocker Shaft Bracket to Cyl Head	90-100	122-136
1/2-20	Standard Torque Specification	83-93	113-126
	Bolt-Blower Rotor Gear Retainer	55-65	75-88
	Nut-Oil Pump Drive Idler Gear Shaft	60-70	81-95
9/16-12	Standard Torque Specification	90-100	122-136
9/16-18	Standard Torque Specification	107-117	145-159
	Nut-Crankshaft Bearing Cap	140-150	190-203
	Bolt-Flywheel	180-190	244-258
	Bolt-Flywheel (V-53)	12-16	16-22
	Bolt-Cylinder Head	140-150	190-203
5/8-11	Standard Torque Specification	137-147	186-199
	Bolt-Starter to Aluminum Flywheel Housing	95-105	129-142
	Bolt-Main Bearing (Boring)	165-175	224-237
	Bolt-Main Bearing (Assembly)	180-190	244-258
	Bolt-Cylinder Head	190-200	258-271
5/8-18	Standard Torque Specification	168-178	228-241
	Bolt-Lube Oil Filter Center	50-60	68-81
	Nut-Alternator Pulley	70-80	95-108
	Nut-Special Self Locking Nut (10SI Alternator)	40-60	54-81
	Bolt-Main Bearing (Boring)	140-155	190-210
	Bolt-Main Bearing (Assembly)	155-185	210-251
	Nut-Cylinder Head	190-200	258-271
3/4-10	Bolt-Crankshaft Main Bearing	280-290	380-393
3/4-16	Standard Torque Specification	290-300	393-407
3/4-16	Nut-Accessory Drive Pulley	120-140	163-190
3/4-18	Nut Standard, Dipstick Tube	30-35	41-47
3/4-24	Bolt-Balance Weight Cover	25-30	34-41
7/8-14	Standard Torque Specification	475-485	644-658
7/8-18	Bolt-Oil Pump Relief Valve Cover	25-35	34-47
1-14	Bolt Crankshaft End	440-460	597-624
1 1/8-18	Nut-Cam and Balance Shaft	300-325	407-441
1 3/4-16	Nut-Transfer Drive Gear (Marsden)	375-400	508-542

	Torque Specs For Detroit Diesel Series 71 (Inline Except 2 Cylinder) Pipe Plug

Plug Size in.	Description	Torque Specifications
Plug Size in.	Description	lb-ft	N-m
1/8-27	Plug-Pipe (3/4 Taper)	10-12	14-16
1/4-18	Plug-Pipe (3/4 Taper)	14-16	19-22
1/4-18	Plug-Pipe (3/4 Taper)	38-42	52-57
1/4-18	Plug-Pipe (7/8 Taper)	14-16	19-22
3/8-18	Plug-Pipe (3/4 Taper)	18-22	24-30
3/8-18	Plug-Pipe (7/8 Taper)	18-22	24-30
1/2-14	Plug-Pipe (3/4 Taper)	23-27	31-37
1/2-14	Plug-Pipe (7/8 Taper)	23-27	31-37
3/4-14	Plug-Pipe (3/4 Taper)	33-37	45-50
3/4-14	Plug-Pipe (7/8 Taper)	33-37	45-50
1-11 1/2	Plug-Pipe (3/4 Taper)	75-85	102-115
1-11 1/2	Plug-Pipe (7/8 Taper)	75-85	102-115
1 1/4-11 1/2	Plug-Pipe (3/4 Taper)	95-105	129-142
1 1/4-11 1/2	Plug-Pipe (7/8 Taper)	95-105	129-142
1 1/2-11 1/2	Plug-Pipe (3/4 Taper)	110-130	149-176
1 1/2-11 1/2	Plug-Pipe (7/8 Taper)	110-130	149-176
1/2-20	Plug-Fuel Pump Relief Valve	18-22	24-30
1 1/4-16	Plug-Oil Filter Bypass valve	95-105	129-142

	Torque Specs For Detroit Diesel Series 71 (Inline Except 2 Cylinder) Stud

Thread Size (in.)	Description	Torque Specifications
Thread Size (in.)	Description	lb-ft	N-m
7/16-20	Stud Standard	30-35	41-47