| The following technical bulletins were published by AERA. |
| | UPDATED CAMSHAFTS | Updated Camshafts On
Cummins L10 Diesel Engines
The Cummins Engine Company has recently updated the available camshafts for L10 diesel engines. The new camshaft surface finish has increased the durability of the camshaft itself and the cam follower assembly.
All previous camshafts have been superseded with new part numbers and previous parts are now obsolete. The new components are not interchangeable with the superseded parts. Cummins has introduced complete replacement kits to ensure proper installation of the new parts where appropriate.
Revised Valve Train Components
Engine Old New New
Desc. Cam P/N Kit P/N Cam P/N
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91 L10 CELECT 3820857 3803645 3895644
When replacing camshaft Part #3820857, order the kit part number.
91 L10 STC LP3 3079585 3803647 3895621
When replacing camshaft Part #3079585, order the kit part number.
91 L10 STC LP1/2 3882534 3803648 3895638
When replacing camshaft Part #3882534, order the kit part number.
88 L10 PT (HOBC) 3820013*
Camshaft Part #3820013, was previously superseded by camshaft, Part #3053006, with a timing change required (see New CPL chart).
88 L10 PT 3053006 3803649** 3895650
When replacing camshaft Part #3053006, order the kit part number.
Pre 88 L10 3037523 3803650 3895662
When replacing camshaft Part #3037523, order the kit part number.
Pre 88 L10 3036117 3803651 3895679
When replacing camshaft Part #3036117, order the new kit part number.
* New Static Timing and new CPL required, refer to chart on next page.
** No CPL change required, product improvement only.
If new camshaft Part #3895650 is installed, it is necessary to adjust the top- stop injector setting. If the stop limit of .198 (5.03mm) is not achieved, injector cup cracking and early camshaft failure may result. This camshaft has a smaller base circle dimension, which results in lower push tube loads than the previous camshaft.
Whenever older engines are updated to newer camshaft components, identify the field updated by stamping #FF-169 on the engine dateplate. Be sure to also stamp the new fuel pump code on the fuel pump data plate.
New CPL Timing Chart
Camshaft Timing Camshaft Key Amount of
Part No. Code Key P/N Config. Offset
---------------------------------------------------------------------------
3820013 3895650
3053006
CPL
Old New Old New New New New
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1223 1619 HK GT 3009948 Arrow Out .0087 (.220mm)
1224 1620 HJ GP 3030894 Arrow Out .0130 (.330mm)
1225 1621 HK GT 3009948 Arrow Out .0087 (.220mm)
1226 1622 HK GT 3009948 Arrow Out .0087 (.220mm)
1346 1623 HK GT 3009948 Arrow Out .0087 (.220mm)
1441 1624 HK GT 3009948 Arrow Out .0087 (.220mm)
1442 1625 HK GT 3009948 Arrow Out .0087 (.220mm)
Timing Code Static Timing Setting
Old New Old New
-------------------------------------------------------------------------
HK GT .082 (2.06mm) +/- .050 .076 (1.93mm) +/- .050
HJ GP .080 (2.03mm) +/- .050 .073 (1.86mm) +/- .050
The AERA Technical Committee | | CRANKSHAFT DAMPER & HUB INSTALLATION FOR GM LT1 | Crankshaft Damper & Hub Installation Caution For
1992-97 GM 5.7L VIN P LT1 Engines
The AERA Technical Committee offers the following information about crankshaft damper and hub installation caution for 1992-97 GM 5.7LVIN P LT1 engines. The following procedure is used on a factory assembled short block / long block assembly. If you are rebuilding the engine and are changing the weight of the pistons, rods or using a different crankshaft rebalancing is highly recommended.
1. Before removing damper place alignment marks on damper hub and front cover for use during installation.
2. After placing alignment marks on the hub and front cover do not rotate crankshaft, as an engine imbalance may result.
3. Remove damper to hub attaching bolts, then remove damper. (See figure1).
4. Remove crankshaft hub bolt and washer, then remove crankshaft hub using tool J39046 or equivalent.
Reverse procedure to install.
If the crankshaft was accidentally rotated after placing alignment marks, position # 1 cylinder at top dead center, then install hub with arrow casting at 12 O?clock position.
Note; If the engine rotating assembly is not going to be balanced and a replacement damper is being installed, balance weights of the same size as used on the original damper must be installed in the same locations on the new damper.
Figure 1. Crankshaft Damper & Hub
The AERA Technical Committee | | VALVE STEM SEAL INSTALLATION | Caution On Installing Valve Stem Seals On
Chrysler, Dodge, Plymouth 5.2, 5.5, 5.8, 6.6 & 7.2L Engines
When installing intake valve stem seals in the subject engines, often the seals are crushed if the valve springs are excessively compressed during installation of valve keepers. Using the valve stem as a guide, the intake valve stem seals should be pressed firmly and squarely over the valve guides.
CAUTION: When installing valve retainer locks, compress the springs just enough to complete the operation. Do not force the seals against the top of the guides.
The AERA Technical Committee | | PISTON AND CONNECTING ROD ASSEMBLY CAUTION | Piston and Connecting Rod Assembly Caution For
1994-2001 GM 2.8, 3.1 & 3.4L VIN J, M, & E Engines
The AERA Technical Committee has received many inquires on the proper piston to connecting rod assembly orientation for 1994-2001 GM 2.8L & 3.1L VIN J, M, & E engines. This topic was not addressed by OE or in aftermarket service manuals. Previous information presented in AERA Technical Bulletin TB 997 is included below along with the most current new information from GM.
Important: Prior to piston /rod removal, mark or identify the piston/connecting rod assembly, and its orientation to the front of the engine, before removal.
Caution: A rod kiln or rod heater must be used during the assembly of the connecting rod to the piston pin. Under NO circumstances should an acetylene torch or other uncontrolled heating device be used on connecting rods, as permanent damage to the connecting rod may result.
Appling excessive heat to the connecting rod may damage or distort the connecting rod or piston. Connecting rod temperature should not exceed 320°C (612°F). Like wise when using a press to assembly rods and pistons, using pressures of more than 5000 psi (35,000 kPa) could damage the connecting rod.
According to sources, most pistons are marked with an arrow or notch that should be pointed toward the front of the engine. Determining the orientation of the connecting rod by disassembling several engines has been inconclusive. In some engines the connecting rod bearing tangs faced toward one side, in others toward the opposite side, or even a combination of the two.
If the connecting rods were not marked for location before disassembly, consider the following information. Since the connecting rod is not offset, for customer satisfaction, mount the pistons so that the bearing tangs point toward the outside of the engine. The arrow or notch on the piston should point toward the front of the engine.
The AERA Technical Committee | | PISTON & CONNECTING ROD ASSEMBLY | Piston and Connecting Rod Assembly On
GM 2.8 & 3.1L Engines
The AERA Technical Committee has received many inquires on the proper piston to connecting rod assembly orientation on GM 2.8L and 3.1L engines. This topic is not addressed by OE or in aftermarket service manuals.
According to sources, most pistons are marked with an arrow or notch that should be pointed toward the front of the engine. Determining the orientation of the connecting rod by disassembling several engines has been inconclusive. In some engines the connecting rod bearing tangs faced toward one side, in others toward the opposite side, or even a combination of the two.
Since the connecting rod is not offset, for customer satisfaction, mount the pistons so that the bearing tangs point toward the outside of the engine. The arrow or notch on the piston should point toward the front of the engine.
The AERA Technical Committee | | CYLINDER HEAD INSTALLATION PROCEDURE FOR 3.8L GM | Updated Cylinder Head Installation Procedure For
1995-2002 GM 3.8L VIN 1 & K Engines
The AERA Technical Committee offers the following information regarding cylinder head installation for 1995-2002 GM 3.8L VIN 1 & K engines. This bulletin should be used and AERA TB 1952 should be discarded. Various other published service information has been incomplete and this bulletin provides the most up to date information.
The cylinder head bolts used for these engines were designed for a one time use and should be replaced anytime the heads are re-installed. Failure to replace the bolts during head installation will yield an improper assembled torque.
Follow the procedure listed below to install new head bolts on these engines. It is suggested a torque angle meter J36660 (or equivalent) be used.
1. Thoroughly clean the threads in the block using a 7/16?14 tap.
2. Install the head gasket with the arrow pointing to the front of the engine.
Figure 1. Cylinder Head Torque Sequence
3. Install the new cylinder head bolts dry. NOTICE: This bolt is designed to permanently stretch when tightened. The correct part number fastener must be used to replace this type of fastener. Do not use a bolt that is stronger in this application. If the correct bolt is not used, the parts will not be tightened correctly. The system or the components may be damaged.
Step 1. Tighten all bolts in sequence to 35-37 ft/lbs (49-50 Nm).
Step 2. Rotate each bolt 130° in sequence. Use the J36660.
Step 3. Rotate the center four bolts 1,2, 3 & 4 an additional 30°. Use the J36660.
The AERA Technical Committee | | INTAKE MANIFOLD REMOVAL & INSTALLATION CAUTION | Intake Manifold Removal & Installation Caution For
1995-2001 GM 3.8L VIN K Engines
The AERA Technical Committee offers the following cautions regarding intake manifold removal and installation for 1995-2001 GM 3.8L VIN K engines. This engine uses an upper and lower intake manifold assembly. It is necessary to remove the upper intake manifold to service the lower intake, as two mounting bolts are located under the upper manifold.
Those two bolts are located in the right front and left rear corners of the lower intake manifold and illustrated below in Figure 1 with numbers 5 and 7. Attempting to remove the two manifolds as an assembly will fracture the mounting location of lower unit.
Figure 1. Lower Manifold Torque Sequence
The caution expressed for installing the lower intake manifold is to make sure and use a locking compound on the bolt threads and to adhere to the minimal torque value used.
1. Clean the cylinder block, heads and the intake manifold sealing surface of all oil with a suitable solvent.
2. Clean the intake manifold bolts and bolt holes of adhesive compound.
3. Apply GM P/N 12345493 approved thread locking compound to the intake manifold bolt threads before assembly.
4. Tighten the mounting bolts in sequence to 11 ft/lbs (15 Nm).
Figure 2. Upper Intake Manifold Torque Sequence.
The upper intake manifold also requires only a minimal torque value of 89 Inch/lbs (10 Nm). Be sure to follow the sequence shown in Figure 2 while tightening each bolt.
NOTE: Lower Intake manifolds used from 1995-98 originally used lower intake manifold Part # 24505728. That manifold should be replaced with the improved manifold Part #24508923 when degrading is observed in the composite material around the EGR stove pipe as shown by the arrow in Figure 3. Replacement of the upper intake with Part #17113136 is also necessary when the improved manifold is used
Figure 3. Possible Degrading of Composite Material
The AERA Technical Committee | | CAUTION ON CONNECTING RODS | Connecting Rod Inspection on
Chevrolet Truck 4.8L (292 CID) Engines
It has been reported that magnetic particle inspections have revealed fatigue cracks in connecting rods on Chevrolet Truck 4.8L (292 CID) engines. Rejection of 15% of the rods was experienced during rod reconditioning. The cracks usually originate behind the bolt head and in the corner radius of the rod.
To avoid costly problems, all members are urged to use magnetic particle inspection on all these rods (forging no. 9420) and to check carefully for fatigue cracks especially in the area indicated by the arrow in the diagram.
The AERA Technical Committee |
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