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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 |
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REVISED CONNECTING ROD |
New Connecting Rod Assemblies On
Navistar (International) DT-466 &
DT/DTI-466B Diesel Engines
A new 45° split line connecting rod assembly with a revised piston pin oil reservoir has been released for DT-466 & DT/DTI-466B diesel engines. The new connecting rod assemblies, which are not shot-peened, replace the old 35° assemblies starting with serial #32813 for the DT-466 engine and serial #75957 for DT/DTI-466B. The thread length of the connecting rod bolts has been
increased from 1.12 (2.84cm) to 1.70 (4.32cm) to facilitate the new design.
Old and new rods can be intermixed for engines in the field. New con rod bolts (676679C2) can be used in old con rod bolts, but OLD BOLTS (676679C1) MUST NOT BE USED IN NEW CON ROD ASSEMBLIES.
The AERA Technical Committee |
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VIBRATION CAUSED BY IMPROPER FLYWHEEL INSTALLATION |
Vibration Problems On
Navistar (International) 2.5, 3.2, 4.4, 5.0, 5.6 & 6.4L
(152, 194, 266, 304, 345 & 392 CID) Engines
Serious vibration problems have been experienced with subject Navistar (International) engines. When a flywheel from these engines is resurfaced the dowel pin should be installed in the correct hole or the flywheel will be bolted in the wrong position.
The flywheel on these engines has an integral cast-in counterweight allowing it to be bolted to the crankshaft in ten different positions if the dowel pin is missing or is installed in the incorrect position. Since the dowel pin in the flywheel is
chamfered and the bolt holes are not, members are cautioned to properly identify it to eliminate the vibration problems.
The AERA Technical Committee |
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REVISED CYL. HEAD GASKET ON 9.0L DIESEL ENGINES |
Revised Cylinder Head Gasket On
Navistar 9.0L Diesel Engines
Navistar International has released a revised cylinder head gasket for the 9.0L diesel engine.
The new head gasket features pre-applied sealant around the water ports. This new technique of gasket making provides increased sealing capabilities.
The new head gasket available by itself or as part of the upper engine gasket set.
Description New Part # Old Part #
Cylinder Head Gasket 489253C3 489253C2
Upper Eng Gasket Set 1701548C96 1700548C95
The AERA Technical Committee |
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CYLINDER HEAD - ENGINE FRONT COVER INTERFERENCE |
Left Cylinder Head Interference With Engine Front Cover On
DV-462B & DV-550B Navistar (International) Engines
It has been reported that in some instances the left cylinder head interferes with the engine front cover upon torquing the cylinder head bolts.
It is advisable to inspect the area shown in the illustration below when head gaskets are replaced on these engines. Interference in this area could prevent proper sealing of the gasket when specified torque is applied to the bolt.
To correct this condition, it is recommended that the cylinder head be removed and only sufficient stock be removed form the cylinder head to eliminate the interference condition.
The AERA Technical Committee |
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CYLINDER HEAD SPECIFICATIONS FOR 6.9L DIESEL |
Cylinder Head Specifications On
Navistar International 6.9L Engines
Due to the extremely close running clearances between the pistons and valves and the pistons and cylinder head, it is extremely important to maintain the proper specifications on this engine when performing cylinder head rebuilding operations.
The cylinder head thickness should be maintained between 4.795 and 4.805. Figure 1 shows that this measurement is taken from the deck surface to the valve cover rail.
Figure 2 shows the valve angles for the Navistar 6.9L engine. Notice that the exhaust valve angle is 37 1/2° while the intake valve angle is 30°. The valve seats have the same angles as the valves.
Again, due to very close running clearances, proper valve recession must be maintained. There is only .009 running clearance between the exhaust valve and the piston when the exhaust valve is fully open. The recession specifications are as follows:
Intake: .042-.054 (1.06mm-1.37mm) A and B models
Exhaust: .043-.055 (1.09mm-1.40mm) A models *
Exhaust: .046-.058 (1.17mm-1.47mm) B models *
* All exhaust valves serviced through Navistar are the B valves only, Navistar part #1 805 917 C1. Use the B specification with all new exhaust valves and the A specification on reused valves where applicable.
When reassembling the Navistar 6.9L cylinder heads, you must snap the valve stem seal onto the bottom of the valve spring retainer. Failure to do so may create coil bind.
The AERA Technical Committee |
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CYLINDER HEAD THICKNESS SPECIFICATIONS |
Cylinder Head Thickness On
Navistar International 9.0 Diesel Engines
Because of very close tolerances between the pistons and valves on Navistar International 9.0L diesel engine cylinder heads, company engineers do not recommend resurfacing the cylinder heads. They do advise that new cylinder heads vary slightly in thickness, and that the minimum acceptable thickness is 4.622. New cylinder heads for the 9.0L diesel engine can be as thick as
4.628.
A number of AERA members report that they have removed up to .010 from the cylinder head without creating problems. The pistons and valves in this engine come very close to each other, and discretion must be used if you're contemplating resurfacing.
Before resurfacing this cylinder head, be sure to advise your customer if you will be reducing the thickness past the minimum acceptable dimension as determined by Navistar International engineers.
The AERA Technical Committee |
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EXCESSIVE OIL CONSUMPTION |
Excessive Oil Consumption On
Navistar (International) Model 2.5, 3.2, 4.4, 5.0, 5.6 & 6.4L
(4-152, 4-196, V-266, 304, 345 & 392) Engines
There are many causes of excessive oil consumption which are generally known to experienced automotive servicemen. In addition to the reasons common to most engines, there is a specific point to check on the subject engines which could be the reason for abnormal oil consumption. This involves the possible seepage or leakage of engine oil through the threaded rocker arm bracket retainer bolt holes, which are drilled and opened into the intake
ports in the cylinder heads of these engines.
The bolts used at these brackets have nylon pellets or patches of sealing material near the thread ends which serve as an oil seal as well as a bolt locking device. A pellet or seal patch missing form a bolt would, by itself, be the cause of oil consumption resulting in heavy oil smoke emission at the tail pipe and frequent necessity to add oil.
When a missing or leaking pellet is suspected, the cylinder at fault can generally be located by removing and examining each spark plug. A fouled or oil wet plug would indicate this problem. Remove the bracket retainer bolt over the intake port leading to the cylinder head showing excess oil and check to determine that a seal is in place. Note the location of the nylon pellet in the
drawing below. A sprayed-on patch of seal material is also used at this point. The bolt (IH 151 462-R2) should be used at each rocker arm bracket and tightened to 14-16 ft.lbs.
Caution: When these bolts are reused, apply a small amount of non-hardening sealing compound to the thread ends to further assure a seal against oil leakage.
The AERA Technical Committee |
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REVISED PISTON RUNNING CLEARANCE |
Increased Piston Running Clearance On
International 5.0, 5.6, 3.2 & 6.4L
(V-304, V-345, 4-196, & V-392) Emission and Non-Emission Engines
To eliminate the possibility of scuffing and scoring of the pistons and cylinder bores on the subject engines, the piston running clearance has been increased as follows:
Former Revised
Engine Models Clearance Clearance
V-304 .0025 .003
V-345 .0025 .003
4-196 .0025 .0035
V-392 .0025 .0035
When fitting pistons to cylinder bores, the bores should be checked with a dial bore gauge and the pistons measured at the bottom of the skirt as shown below with an outside micrometer.
The AERA Technical Committee |
