Cummins NH, NT, NTA, NTC-475 1981 Workshop Manual – 390 Pages

Description

If you’ve ever tried rebuilding a Cummins 855 with a generic online PDF, you know the problem: wrong torque values, missing steps, no worn limit tables. That’s why I keep a 1981 OEM print of the Cummins NH, NT, NTA, NTC-475 1981 Workshop Manual in my toolbox. 390 pages of factory-sourced rebuild procedures for the NH, NT, NTA, and NTC-475 engine families. Aftermarket guesswork has no place in a rebuild – this is the original Cummins documentation.

Cummins NH, NT, NTA, NTC-475 1981 Workshop Manual: The Only Source for OEM Torque Values

Torque values are the backbone of any rebuild. Get them wrong and you either strip threads or blow a head gasket. This manual puts torque specs at the end of each group, right next to the worn limits table. Page 1 of the foreword lists torque values as part of the manual content. For example, the cylinder head bolt torque sequence is given in Group 1 with a specific final torque in ft-lbs. You also get bearing cap and connecting rod torque. These are numbers from the Cummins engineering department, not some third-party translation.

Engine Disassembly and Component Groups

The manual is split into 22 groups. Group 0 covers complete engine disassembly. Group 7 covers the lubricating system including oil pump disassembly, inspection, and assembly. Each group starts with an exploded view and a list of required tools. If you are rebuilding an NTA-855 Big Cam II (MVT), the procedures are in there. The manual explicitly states that fuel pump, air compressor, injectors, and turbochargers are not included – you need separate manuals for those.

Does This Manual Cover Turbochargers and Fuel Pumps?

On page 1 the manual says these components are not included. That means you cannot use this book to rebuild a Holset or PT pump. You need the specific Cummins service manual for those parts. For the engine block, cylinder head, pistons, liners, crankshaft, lubrication, cooling – this book has it all.

Identify Your Engine Model Before You Open the Manual

Page 2 shows the model number breakdown. Example: NTA-855-C360 – NH series, Turbocharged, Aftercooled, 855 CID, Construction application, 360 HP. If you don’t check the dataplate, you might grab the wrong group. Safety first – always verify.

Tools Required for Each Group

Each group lists special tools designed by Cummins for specific procedures. You will see things like “Cummins Injector Puller” or “Crankshaft Turning Tool”. Standard tools like torque wrenches and sockets are also listed. Not having the right tool can damage parts – do not improvise.

For other Cummins engines, see Cummins X1.7, X2.5 2010 Workshop Manual – Factory OEM PDF or Cummins X 1.3 Series 2010 Workshop Manual – OEM Specs & Procedures. The N14 family is covered in Cummins N14 1991 Workshop Manual – OEM Factory Rebuild Specs.

This engine mates to various Manual Transmission units. For transmission service, refer to the appropriate OEM manual. Also, if you need Manual Transmission rebuild specs, they are not in this engine manual.

Frequently Asked Questions

Is this a reprint or a copy?

Original factory print from 1981. Not a reprint.

What specific torque values are listed for the NH head bolts?

Each group ends with a worn limits and dimensions table that includes torque values for that assembly. For example, the cylinder head torque sequence and final torque are specified in Group 1 (Cylinder Head). You also get torque values for main bearing caps, connecting rod bolts, and flywheel mounting. These are OEM numbers, not aftermarket approximations. If you follow the manual exactly, you won’t have head gasket leaks or stretched bolts. I’ve seen too many shops skip the torque sequence and pay for it later.

Forget third-party data. Access the Factory Manual and rebuild with the same specs Cummins engineers wrote in 1981. It’s the only way to be sure your torque wrench settings are right.