Hummer H1 (1992-1998). Manual - part 1

CHAPTER 1

INTRODUCTION

Section I. GENERAL INFORMATION

This technical manual contains instructions for direct support and general support maintenance of
the 6.2 liter naturally aspirated, 6.5 liter naturally aspirated detuned, and 6.5 liter turbo V-8 diesel engines.

1-1. SCOPE

(Army) Department of the Army forms and procedures used for equipment maintenance will be those
prescribed by DA Pam 738-750, The Army Maintenance Management System (TAMMS). (Marine Corps)
Refer to MCO 4855-10.

1-2. MAINTENANCE FORMS, RECORDS, AND REPORTS

Procedures for destruction of Army tank-automotive equipment to prevent enemy use are found in
TM 750-244-6.

1-3. DESTRUCTION OF ARMY EQUIPMENT TO PREVENT ENEMY USE

(Army) Refer to TM 746-10, Marking, Packaging, and Shipment of Supplies and Equipment: General
Packaging Instructions for Field Use. (Marine Corps) Refer to MCO 4450-7.

1-4. PREPARATION FOR SHIPMENT

Calibration requirements in this manual cover the fuel injection pump and can be found in paras. 2-33, 
2-34, and 2-35 of this manual.

1-5. EQUIPMENT REQUIRING CALIBRATION

If your vehicle needs improvement, let us know. Send us an EIR. You, the user, are the only one who can
tell us what you don’t like about your equipment. Let us know why you don’t like the design or
performance. The preferred method for submitting QDRs is through the Army Electronic Product Support
(AEPS) website under the Electronic Deficiency Reporting System (EDRS). The web address is:
https://aeps.ria.army.mil. This is a secured site requiring a password that can be applied for on the front
page of the website. If the above method is not available to you, put it on an SF 368, Product Quality
Deficiency Report (PQDR), and mail it to us at: Department of the Army, U.S. Army Tank-automotive and
Armaments Command, ATTN: AMSTA-TR-E/PQDR MS 267, 6501 E. 11 Mile Road, Warren, MI 48397-500.
We’ll send you a reply. (Marine Corps) Submit QDR’s in accordance with MCO 4855-10.

1-6. REPORTING EQUIPMENT IMPROVEMENT RECOMMENDATIONS (EIRs)

Change 2        1-1

1.7. EQUIPMENT IMPROVEMENT REPORT AND MAINTENANCE DIGEST (EIR MD)

The quarterly Equipment Improvement Report and Maintenance Digest, TB 43-0001-62 series, contains
valuable field information on the equipment covered in this manual. The information in the TB 43-0001-62
series is compiled from some of the Equipment Improvement Reports that you prepared on the vehicles
covered in this manual. Many of these articles result from comments, suggestions, and improvement
recommendations that you submitted to the EIR program. The TB 43-0001-62 series contains information
on equipment improvements, minor alterations, proposed Modification Work Orders (MWOs), warranties (if
applicable), actions taken on some of your DA Form 2028s (Recommended Changes to Publications and
Blank Forms), and advance information on proposed changes that may affect this manual. The information
will help you in doing your job better and will help in keeping you advised of the latest changes to this
manual. Also refer to DA Pam 25-30, Consolidated Index of Army Publications and Blank Forms, and
appendix A, References, of this manual. (Marine Corps) Submit QDR’s in accordance with MCO 4855-10.
For those with access to the World Wide Web (WWW), the EIR MD can be viewed through the Army
Electronic Product Support. The site is http://aeps.ria.army.mil.

1-8. METRIC SYSTEM

The engines described herein contain metric components and require metric common and special tools;
therefore, metric units in addition to standard units will be used throughout this publication. In addition,
a metric conversion table is located on the inside back cover of this publication.

 1-9. MANDATORY REPLACEMENT PARTS 

The maintenance instructions contained herein make reference to removing and discarding piece parts such
as: gaskets, lockwashers, cotter pins, O-rings, seals, etc.; these items should be considered mandatory
replacement items and replaced with new parts during assembly/installation.

Section II. EQUIPMENT DESCRIPTION AND DATA

1-10. DESCRIPTION

The engine used in the M998 series vehicles is an eight-cylinder, four-cycle, liquid-cooled, naturally

aspirated diesel engine. The 6.2L engine has a compression ratio of 21.5:1 and develops approximately 150

horsepower (112 kW) at 3600 rpm. The 6.5L engine has a compression ratio of 21.5:1 and develops

approximately 160 horsepower (119 kW) at 3400 rpm. For proper orientation, the left and right sides of the

engine are as viewed from the rear.

1990 and above 6.2L and 1994 6.5L engines have the following new and revised parts:

*Cylinder Heads. The 1990 cylinder heads have been revised to meet 1990 emissions standards.
Precombustion Valves. The 1990 engine is equipped with reverse throat precombustion chambers.
Exhaust Valves. The 1990 exhaust valves are coated with chrome to prevent burning and to
increase durability.
*Exhaust Valve Stem Seal. The 1990 engine is equipped with a new exhaust valve stem seal that
is not available for previous model engines.
Cylinder Head Gaskets. The 1990 cylinder head gaskets have new circular combustion seals and
are made of a non-asbestos material.
Fuel Injection Pump. The 1994 fuel injection pump has a TP sensor and a revised calibration
procedure.

Fuel Injection Pump. The 1990 fuel injection pump has a new governor and a revised calibration
procedure.
*Fuel Injection Nozzles. The 1990 fuel injection nozzles are shorter and are orientated ten degrees
from the vertical.
*Fuel Injection Lines. The 1990 engine is equipped with high pressure fuel injection lines.
Fuel Injection Line Brackets. The 1990 fuel injection line brackets have been revised to provide
clearance for the injection nozzles.
*RPM Sensors.  The 1994 engine is equipped with two rpm sensors. One is for STE-ICE-R and one is
for the engine.
*Fan Cut-Off Switch.  The 1994 engine is equipped with a fan cut-off switch which replaced the
kick-down switch.

*These 1990 parts are not interchangeable with parts for previous model engines. Differences in
maintenance procedures are identified where applicable. Refer to engine decal number on left rocker
arm cover before ordering replacement parts.

1-2

The 1990 6.2L engine is identified by a decal which is adhered to the left rocker arm cover. The 6.5L

engine is identified by a serial number bar code decal.

 1-11. COMPONENT LOCATION 

The locations of components described below are common to all engines in the M998 series vehicles.

Special differences are described in para. 1-10.

FAN CLUTCH

ROCKER ARM COVERS (2)

FUEL INJECTORS (8)

OIL FILTER

EXHAUST MANIFOLDS (2)

OIL PAN

TIMING GEAR COVER 

CRANKSHAFT PULLEY

INTAKE MANIFOLD

FUEL INJECTION PUMP

WATER CROSSOVER

WATER PUMP

FUEL PUMP

GLOW PLUGS (8)

1-3

1 - 1 2 . TA B U L ATED DATA

Engine tabulated data is listed in tables 1-1 and 1-2. This information includes only those data applicable to
direct support and general support maintenance. Information not covered can be found in TM 9-2320-280-20
and TM 9-2320-280-10.

1-4

Change 1

MEASUREMENT

ABBREVIATION

MEASUREMENT

ABBREVIATION

Quart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . qt

Celsius . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C

Kilogram . . . . . . . . . . . . . . . . . . . . . . . . . . . . kg

Liter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L

Inch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . in.

Centimeter . . . . . . . . . . . . . . . . . . . . . . . . . . cm

Pound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . lb

Millimeter . . . . . . . . . . . . . . . . . . . . . . . . . . mm

Pounds Per Square Inch . . . . . . . . . . . . . . . . psi

Kilopascal . . . . . . . . . . . . . . . . . . . . . . . . . . kPa

Revolutions Per Minute . . . . . . . . . . . . . . . . rpm

Newton Meter . . . . . . . . . . . . . . . . . . . . . . . N

•

m

Pound-Feet . . . . . . . . . . . . . . . . . . . . . . . . . lb-ft

Horsepower . . . . . . . . . . . . . . . . . . . . . . . . . . hp

Cubic Inch . . . . . . . . . . . . . . . . . . . . . . . . . cu-in.

Kilowatt . . . . . . . . . . . . . . . . . . . . . . . . . . . . kW

Fahrenheit . . . . . . . . . . . . . . . . . . . . . . . . . . . F

Manufacturer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Detroit Diesel Allison

Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2 L

Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Four-cycle, liquid-cooled, naturally aspirated

STANDARD

METRIC

Dimensions:

Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35 in.

89 cm

Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

28 in.

71 cm

Height

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

28 in.

71 cm

New weight, dry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

650 lbs

295 kg

Cylinders:

Number

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Eight

Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

90° V

Firing order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-8-7-2-6-5-4-3 (clockwise)

Bore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.98 in.

10.1 cm

Stroke (nominal) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.82 in.

9.7 cm

Displacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

392 cu-in.

6.2 L

Compression ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21.5:1

Maximum Torque (gross) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

260 lb-ft @ 2000 rpm

353 N

•

m @

2000 rpm

Governed Speed:

Full load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3600 rpm

No load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4000 rpm

Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

650±25 rpm

Lubrication System:

Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Pressure feed

Operating pressure (normal)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

40-50 psi

276-345 kPa

Operating pressure (at idle)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10 psi

69 kPa

System capacity (including filter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8 qts

7.6 L

Operating temperature (normal) . . . . . . . . . . . . . . . . . . . . . . . . . . . .

180°-260°F

82°-126°C

Oil pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gear-driven

Cooling system:

Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Liquid with fan and radiator

Operating temperature (normal) . . . . . . . . . . . . . . . . . . . . . . . . . . . .

190°-230°F

88°-110°C

TA B U L ATED DATA ABBREVIAT I O N S

Table 1-1. Tabulated Data  (6.2 L)

NOTE

Standard and metric measurements will be used in this table. 
A list of their abbreviations is provided above.