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INTERCHANGEABILITY OF CRANKS, CAMS & TIMING GEARS |
Caution On Interchangeability Of Crankshafts,
Camshafts & Timing Gears On
International DV-462, DV-550, DV-462, & DV-550B Engines
Note: The above engine models differ in designation only in that the later engines have a suffix B.
The suffix B engines are equipped with Holley fuel injection pumps and require Tufftrided gear trains.
In manufacture it was found that the tufftriding process increased the bore diameters of camshaft and crankshaft gears to the point that there were insufficient interference fits when installed. Therefore, camshafts and crankshafts intended to be used in suffix B engines had to be manufactured with larger gear receiving diameters. It is for this reason they are not interchangeable.
Crankshafts and camshafts removed from or intended for DV-462 and DV-550 engines must not be used in conjunction with Tufftrided gear trains in engines with suffix B.
It is suggested that interference fits should be verified by measurement before applying timing gears. If the use of new crankshafts and camshafts is prohibitive, rebuilding of the gear receiving diameters is required to ensure proper interference fits.
In addition to the above, on all suffix B engines the camshaft gear nut torque has been increased from 100 to 200 ft.lbs.
Crankshaft pulley nut torque has been increased from 150 to 325 ft.lbs.
The AERA Technical Committee |
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CYLINDER HEAD BOLT SPECIFICATIONS |
Torque Specifications For Detroit Diesel Allison
Series 92 Cylinder Head Bolts
Care must be taken that the correct torque specification is used
when torquing cylinder head bolts on the Series 92 engine. If
both the cylinder head bolts and the cylinder block are reused, a
torque of 200-210 ft lbs (271-285 N·m) should be used to allow
for adequate clamping of the cylinder head while minimizing
stress loads on the cylinder head and block.
If either the cylinder head bolts or the cylinder block are new,
use the torque specification of 230-240 ft lbs. (312-325 N·m).
The following chart will help illustrate correct torque usage:
Cyl Head Bolt Cyl Block Torque
New New 230-240 ft lb
New Reused 230-240 ft lb
Reused New 230-240 ft lb
Reused Reused 200-210 ft lb
A small amount of International Compound #2 or equivalent should
be applied to the threads and underside of all cylinder head
bolts before tightening them. Following the sequence shown
below, tighten the 11/16-11 bolts to the correct specification
in increments of 50 ft lbs (68 N·m) torque. Tighten close to but
not over the maximum specification.
The first bolts tightened in the sequence may lose clamp load
during tightening of the remaining bolts, therefore, repeat the
tightening sequence at least once. Apply steady pressure for two
or three seconds at the prescribed torque to allow the bolts to
turn while the gaskets yield to their designed thickness. Do not
attempt to tighten the bolts in one step since difficulties such
as compression leaks may result when the engine is put into
operation
PLEASE NOTE: Tightening the cylinder head bolts will not
correct a leaking compression gasket or seal. The
head must be removed and the damaged gasket or
seal replaced.
(insert illustrations)
CYLINDER HEAD BOLT TIGHTENING SEQUENCE
The AERA Technical Committee
November 1984 - TB 332
##END## |
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REV. MAIN BEARING BOLT TORQUE PROCEDURE ON 71 SER. |
Revised Main Bearing Cap Bolt Tightening Procedure For
Series 71 Detroit Diesel Allison Engines
Detroit Diesel Allison has revised the method of tightening
Series 71 man bearing cap bolts. Under certain conditions, the
original torque-turn method may apply a higher clamp load than is
actually required. This higher clamp load can lead to main
bearing bore distortion. For this reason, you should no longer
use the torque-turn method of tightening in-line and V-71 main
bearing cap bolts.
The following procedure has been released by DDA to tighten
Series 71 main bearing cap bolts:
1. Install the lower main bearing shells n the bearing
cap.
2. Apply a small quantity of International Compound No. 2
or equivalent to the threads of the bolt or stud and
nut and the contact area of the bolt head or nut.
3. Install the bearing caps and draw the bolts or nuts up
snug.
4. Rap the caps sharply with a soft hammer to properly
seat them.
5. Bolts are tightened to 190-200 ft lbs (258-272 N.m).
Studs and nuts are tightened to 155-185 ft lbs (211-251
N.m) for cast iron blocks and 120-140 ft lbs (163-190
N.m) for aluminum blocks. Do not exceed the specified
torque.
DDA advises that if the bearings have been installed properly,
the crankshaft will turn freely with all of the main bearing cap
bolts drawn to the specified torque.
The AERA Technical Committee
March 1987 - SPB 141
##END## |
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PISTON RING END GAP SPECIFICATIONS |
Piston Ring End Gap
Navistar 6.9L & 7.3L Diesel Engine
Navistar International has been using an increased piston ring gap on the second compression ring. Both the 6.9L & 7.3L engines have a minimum second ring end gap of .060 (1.52 mm) (see chart and illustration). That figure seems larger than what is commonly found for piston ring end gap. Navistar uses the wider end gap to aid in oil control, and to lower engine emissions. Using a wider
end gap in the second ring land evens out the pressures in the ring land area of the piston.
AERA cautions members to use the following piston ring gap specifications when rebuilding the 6.9L and 7.3L Navistar Diesel engines.
6.9L Piston Ring Gap
Top Ring .014-.024 (.05-.61 mm)
2nd Ring .060-.070 (1.52-1.78 mm)
Oil Control Ring .010-.024 (.25-.61 mm)
7.3L Piston Ring Gap
Top Ring .013-.045 (.33-1.14 mm)
2nd Ring .060-.085 (1.52-2.16 mm)
Oil Control Ring .008-.030 (.20-.76 mm)
The AERA Technical Committee |
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TESTING ENGINE BLOCKS AND CYLINDER HEADS |
Heated Water Recommended For Test Tank
When pressure testing engine blocks, cylinder heads, oil cooler
cores, etc., it is recommended that the water temperature in the
test tank be brought up to 180^ - 200^ to simulate actual
operating conditions.
A part which leaks may do so only when expanded by heat. If
unheated water is used and no expansion occurs, the component may
not leak during the pressure test. As a result, a defective part
could escape detection in the tank, only to show up again on the
engine.
The AERA Technical Committee
August 1974 - SPB 23
##END## |
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INSTALLATION OF ALUMINUM GEARS |
Caution On Press Fitting Of Aluminum Timing Gears
When heating aluminum timing gears prior to press fitting on camshafts, caution should be exercised that the gears are not heated above 200^ Fahrenheit. When subjected to extreme temperatures, aluminum gears do not return to their original dimensions after cooling. The result is a loose fit between gears and camshaft. Under no circumstances should aluminum gears be heated with a torch.
The AERA Technical Committee |
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REVISED CYLINDER HEAD GASKET ON 3406B ENGINES |
Revised Cylinder Head Gasket On
Caterpillar 3406B Diesel Engines
Caterpillar Tractor has released an improved cylinder head gasket for all 3406B truck engines.
The revised cylinder head gasket carries part #7E6000 and replaces part #2W7983, 9Y7786 and 7E3240. Several improvements have been made to the gasket in the armor (fire ring) and front and rear edges of the gasket. A thicker stainless steel armor compensates for the non-asbestos facing material. This should ensure better crush when the cylinder head is torqued in place.
Reducing the armor overlap increases loading of the gasket body while reducing the possibility of fluid leaks. The front and rear edges of the gasket body are filled in between the bolt holes.
This provides increased support for the armor.
The revised gasket is coated with single layer of black Teflon (PTFE) on the spacer plate side. The Teflon prevents sticking of the gasket to the aluminum spacer plate. There is no coating on the opposite side.
Torque the cylinder head bolts in several steps using the torque sequence diagram show below.
Step 1 Tighten bolts 1 through 20 in sequence to 200 +/- 20
lbs.ft.
Step 2 Tighten bolts 1 through 20 in sequence to 330 +/- 15
lbs.ft.
Step 3 Retighten bolts 1 through 20 in sequence to 330 +/- 15
lbs.ft.
Step 4 Install the rocker arm shaft assembly.
Step 5 Tighten bolts 21 through 26 in sequence to 200 +/- 20
lbs.ft.
Step 6 Tighten bolts 21 through 26 in sequence to 330 +/- 15
lbs.ft.
Step 7 Retighten bolts 21 through 26 in sequence to 330 +/- 15
lbs.ft.
Step 8 Tighten the twelve 3/8 bolts to 32 +/- 5 lbs.ft.
Installing the revised headgasket eliminates retorqueing of the head bolts as part of the first service completely. Only the new gasket is being service by Caterpillar. All former designs have been discontinued.
The AERA Technical Committee |
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FLYWHEEL SPECIFICATIONS |
Flywheel Specifications For Allis Chalmers Tractors
The following chart of flywheel specifications may be referred to when surfacing or machining flywheels on Allis Chalmers agricultural tractors.
Casting Tractor Cup (A) (B) Dimension,
Number Model Dimension (New) Minimum Height
-----------------------------------------------------------------
249869 175D 1.437+/-.005 1.938
257542 175G, 170G 1.437+/-.005 1.085
D17G
4006698 190XT 1.437+/-.005 0.617
4513397 D19 G & D 1.437+/-.005 0.617
4024119 185 G & D 1.437+/-.005 0.617
200,7000
7010 & 7020 PS
4029209 210,220,D21 2.042+/-.005 0.682
4029522 7030, 7050 0.178+/-.005 0.858
4007689 7010 & 7020PD 0.178+/-.005 0.908
4035711 7040,7060 0.178+/-.005 0.858
7080,7580
4035834 7040,7060,7080 0.178+/-.005 0.858
7045 PS & PD
4028150 7040 & 7060 PS 1.437+/-.005 1.472
4396100 8550 1.100+/-.010 1.148
All new flywheels have the capablility of .062 stock removal from the friction pad surface at time of manufacture. If a flywheel is measuring at or less than the minimum height, it should be replaced.
The AERA Technical Committee |
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NEW GASOLINE ENGINE OIL CLASSIFICATION SH |
New Gasoline Engine Oil Classification SH
The American Petroleum Institute (API) has released a new gasoline engine oil category SH. Engine oils meeting this classification should be used in all 1994 and later gasoline engines. This oil may also be used in gasoline engines
manufactured before the 1994 model year.
As EPA emission laws continue to evolve, manufacturers of gasoline engines have been forced to follow tougher standards with lower total emissions. As those demands continue, engine oils have also required improvements. The oil classification SH, provides better protection against rust, oxidation, sludge,
varnish and extended component life expectancy.
Oils branded with the SH moniker are tested under the tougher Engine Oil Licensing and Certification System (EOLCS). This new system requires oil to pass either the first time tested, or pass on an average score of multiple samples tested. Previously oils could continue to be tested until passing results were generated.
Oils that pass the SH test and meet Energy Conserving II (ECII) requirements may use a new starburst logo indicating certification from the International Lubrication Standardization & Approval Committee (ILSAC). This new symbol is designed to allow consumers to readily identify oils that conform to the latest engine oil standards. Along with the starburst logo, the familiar API donut will display the oil's viscosity and SH classification. Oils not conforming to the ECII requirements may display the SH rating without the new starburst symbol.
The AERA Technical Committee |
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NEW ROCKER ARM SHAFTS |
New Rocker Arm Shaft Assembly Released On
Navistar (International) 3.2, 5.0, 5.6 & 6.4L
(196, V-304, V-345 & V-392 CID) Engines
A new rocker arm shaft assembly is now available for the 196 and small V-8 engines. The new shaft assembly has 4 less rocker arm shaft support brackets per cylinder head than the previous shaft assembly.
The four support brackets and their mounting bolts are replaced by springs, new shorter nylon patch bolts and hardened flat washers to seal the previous support bracket mounting bolt holes.
This change was incorporated into production starting with the following engine serial numbers:
Engine Model Starting Engine S/N
V-304, 345, 392 1492201
V-304A, 345A 280934
4-196 59231
The new rocker arm shaft assembly is serviced in a kit. The .312- 18 UNC x .500 bolts with nylon patches which are included should be torqued to 155-190 in.lbs. (18-20Nm).
The AERA Technical Committee |
