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REVISED CYL HEAD & BLOCK ON 1987-UP ENGINES |
Revised Cylinder Head & Block On
1987-Up Nissan 3.0L (VG30) Engines
Beginning with April, 1987 production, the cylinder heads and
block have been changed on Nissan 3.0L (VG30) engines.
Improvements were made to increase power output and decrease
noise levels of the engine.
Revised production engines can be identified by an engine serial
number that ends in W, such as XXXXXX W. Former engine serial
numbers end in either A or B. However, factory service
cylinder blocks will not carry the W identification even though
they feature the improvements listed below. A visual check is
necessary for proper identification.
Six new water galleries were added to the cylinder block (Figure
1) and the cylinder heads (Figure 2). This change required a
modification of the cylinder head gasket, where the original 6
water holes were downsized and 3 new holes added on the exhaust
side of the gasket (Figure 3). The revised cylinder head gasket
can also be identified by its differing identification tab.
Figure 4 best illustrates the former and revised head gaskets.
Additional changes were made throughout the engine. The pistons
now use full floating, larger diameter wrist pins. The small end
bore of the connecting rod was increased to accept the larger
wrist pin. The revised rod is also heavier than the former part.
Again, components are identified by a W stamp.
Nissan advises against the use of former parts when servicing
vehicles with engines manufactured as of April 1987. Refer to
the chart to determine the proper component combination when
servicing engines manufactured prior to April 1987 (Figure 5).
For additional information see AERA Technical Bulletins: TB 601,
653 & 752
The AERA Technical Committee
Cylinder Head Cylinder Short Acceptable
Head Gasket Block Block Combination
Revised Former Former N/A Yes
Former Former Revised N/A Yes
Former Former Former N/A Yes
Revised Revised Revised N/A Yes
Revised Former Revised N/A Yes
Revised Revised Former N/A No
Former Revised Revised N/A No
Former Revised Former N/A No
Former Former N/A Revised Yes
Revised Revised N/A Revised Yes
Revised Former N/A Revised Yes
Former Revised N/A Revised No
April 1991 - TB 761
##END## |
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REVISED CRANKSHAFT |
Revised Crankshaft On
1984-87 Nissan VG30 Engines
Nissan has revised the snout of the crankshaft and related
service parts for VG30 engines manufactured after April 1987.
Since only the revised crankshaft is being serviced by Nissan,
should it become necessary to use this crankshaft in 1984-1987
engines, several associated parts also need to be changed.
Engines manufactured prior to April 1987 carry a serial number
that ends in either 'A' or 'B'.
Component Prior to As of
Description April 1987 April 1987
Crankshaft 12201-02P80 1 12201-02P81 2
Bolt Spacer Not Required 12308-V5321
Crank Pulley Bolt Washer 12308-V5000 3 12308-77A00
12308-V5001 3
12308-V5010 3
Crank Pulley Bolt 12309-V5000 12309-16V00
1 Does not include crankshaft pulley bolt washer or
crankshaft pulley bolt.
2 Includes crankshaft bolt spacer, crankshaft pulley bolt and
crankshaft pulley bolt washer.
3 Complete application information available on parts
microfiche
The front pulley assembly is the same for either crankshaft.
The AERA Technical Committee
March 1991 - TB 752
##END## |
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REVISED TIMING COMPONENTS |
Revised Timing Components On
1988 Nissan Z24I Engines
Nissan has revised the timing components used in 1988 and later Z24I engines. The actual production change was instituted in January of 1988.
The chain assembly was updated from a single roller to a double roller type. This update requires a new crankshaft and camshaft sprocket as well as the new double roller chain. The tensioner assembly and chain guides have not been changed. Engines manufactured prior to January 1988 may be serviced with the new components as long as all three pieces are used.
The AERA Technical Committee |
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SEIZED CAMSHAFTS |
Seized Camshafts On
Nissan SOHC VG30 3.0L Engines
AERA has received reports of sudden camshaft seizures on Nissan SOHC VG30 3.0L engines. This seizure is uncommon because the cause of the failure is a broken cylinder head bolt. The head of the bolt breaks off and then becomes lodged under one of the cam lobes, resulting in the timing belt either breaking or stripping.
If this type of failure occurs, removal of valve covers will reveal that the bolt head is lodged underneath the camshaft. Further engine disassembly is now necessary as this is a non-freewheeling engine. Bent valves can be encountered on both cylinder banks, even if only one camshaft as seized.
For additional information see AERA Technical Bulletin: TB 601 &
TB 653
The AERA Technical Committee |
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TIMING CHAIN GUIDE ELIMINATION |
Timing Chain Guide Elimination On
1991-93 1.6L DOHC Nissan Engines
The AERA Technical Committee has received information concerning the elimination of two timing chain guides on 1991-93 1.6L DOHC engines. Beginning with engines produced in March 1993, the top and left side timing chain guides were eliminated.
All replacement cylinder heads Part #11040-57Y01, will not have the drilled holes to attach the chain guides. Those guides are not necessary and may cause an undesirable rattling noise when the timing chain contacts the guide. To prevent a possible noise complaint, Nissan suggests removing the two guides shown in the illustrations below anytime cylinder head repair is done.
The AERA Technical Committee |
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NISSAN L24E CRANKSHAFT DIMENSION CHANGES |
Dimension Changes On
Nissan L24E Crankshafts
The Nissan Motor Corporation made a production change in the size of the connecting rod journal diameter on the crankshafts in its L24E engines beginning in July, 1982. Prior to this date the connecting rod journal diameter was 1.967 - 1.9675 (49.961mm - 49.974mm). The company's later engines have a manufactured connecting rod journal diameter of 1.7701 - 1.7706 (44.960mm -
44.973mm).
In a similar fashion, the housing bore diameter of the connecting rods was reduced to accommodate the smaller connecting rod bearings. The earlier style L24E engine connecting rods had a housing bore of 2.0866 - 2.0870 (53.00mm - 53.01mm). The late style connecting rod produced by Nissan after July, 1982 has a housing bore diameter of 1.8894 - 1.9989 (47.99mm - 48.00mm).
The main bearing journal diameter remains the same at a specification of 2.1630 - 2.1636 (54.942mm - 54.955mm) for both the early and late crankshafts.
The AERA Technical Committee |
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CRANKSHAFT CHANGES IN DDA SERIES 92 ENGINES |
Crankshaft Changes On
DDA Series 92 Engines
Detroit Diesel Allison has released new crankshafts and
crankshaft timing gears for all Series 92 engines. These changes
began with the following engine serial numbers: 6VF0123940,
8VF098671, 12VF002032 and 16VF006468.
The new crankshafts have greatly increased journal and main
bearing life by providing up to a 50% thicker oil film on the
main bearing journals during engine operation. The thicker oil
film has been achieved by offsetting the oil holes approximately
90 degrees from the former crankshafts. The oil holes now
intersect at an angle instead of being drilled straight through
(see Figure 1).
(Insert Illustration)
The newly designed crankshafts are unidirectional. Do not
intermix right-hand and left-hand rotation crankshafts. Right-
hand rotation crankshafts must be used in right-hand rotation
engines and left-hand rotation crankshafts must be used in left-
hand rotation engines.
The new crankshaft timing gears have a hole drilled in their bolt
flanges to accept a 1/4 x 3/4 long roll pin (see Figure 2).
The location of this roll pin prevents installing left-hand
rotation gears on right-hand crankshafts and vice versa.
(Insert Illustration)
A seven-digit forging number on one of the counterweights
followed by the letter R or L distinguishes a new design
crankshaft from an old one. In addition, the 12V and 16V-92
crankshaft halves also include FRH (Front Right-Hand), RRH
(Rear Right-Hand), FLH (Front Left-Hand), and RLH (Rear Left-
Hand). These marks designate the position of each crankshaft
half and the marks must be lined up when the halves are
assembled.
The oil pump drive gear area on the 8V-92 crankshaft has been
increased in diameter to provide a press-fit for the oil pump
drive hub. This requires the use of a new drive hub, DDA part
#8927135.
The new crankshafts with their respective timing gears are
completely interchangeable with the former crankshafts and timing
gears for the same engine rotation. DDA will be servicing these
engines with the new parts only.
The AERA Technical Committee
December 1986 - TB 413
##END## |
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TWO PIECE PISTON ASSEMBLY CAUTION |
Two Piece Piston Assembly Caution For
1993-2000 Navistar 530 and 530E Diesel Engines
The AERA Technical Committee offers the following information regarding a two piece piston assembly caution for 1993-2000 Navistar 530 & 530E diesel engines. This information applies to engines with a horsepower rating of 300 and higher.
Engines with a horsepower rating of 300 and higher are equipped with two-piece (articulated) pistons. The top portion of the piston is referred to as the piston crown, while the lower portion is referred to as the piston skirt. A revised articulated piston with an offset pinhole was introduced starting with engine serial #1034668 for the 530 engines and serial #1027887 for the 530E engine.
When assembling the revised offset pinhole pistons together, it is important that it is orientated correctly. For correct assembly alignment of the piston, identification marks have been implemented. The piston crown has a nib (obstruction block) on one of the piston pin bosses and the piston skirt has a raised triangle as part of the skirt casting as shown in Figure 1. When assembling the piston, the raised-formed triangle on the skirt must be lined up with the nib on the piston crown located on the piston pin boss. If the piston is not assembled as described above, an audible piston slapping noise will occur during engine operation.
It is acceptable to use the new piston crown and skirt in place of the old crown and skirt, but the new crown cannot be used with the old skirt or vice versa. The new crown and skirt must be used together. Refer to the chart below for ordering piston crowns and piston skirts for the 530 & the 530E engines.
New Part # Description Old Part # Engine
1829847C1 Piston Crown 1819196C2 530
1826414C1 Piston Skirt 1822501C1 530
1826412C1 Piston Crown 1825587C1 530E
1826414C1 Piston Skirt 1822501C1 530E
The AERA Technical Committee |
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CRANKSHAFT CAUTION |
Crankshaft Caution For
1995 GM 3.8L VIN K, L & 1 Engines
The AERA Technical Committee offers the following information on a crankshaft caution for 1995 GM 3.8L VIN K, L & 1 engines. The crankshaft used in these engines is lighter in weight and has smaller counterweights than previous year?s crankshafts. Therefore using the lighter crankshaft in an earlier engine may produce an undesirable engine vibration (or vice versa).
Beginning in 1995, GM redesigned the 3800 engine and assigned VIN code K (RPO L36) to it. That design is also referred to as the Series II engine. The engine manufacturer also applied this revised design crankshaft (and other components) to its other 3.8L engines with VIN codes of L and 1. This crankshaft is available from GM with Part # 24502168 and it is identified with a raised casting number 2170. The crankshaft also has a six-inch (approximately) diameter front counterweight as shown in Figure 1 below. Earlier crankshafts had a six and ? inch (approximately) diameter front counterweight.
Interchanging an earlier VIN L & 1 crankshaft with a 2170 crankshaft is not recommended, even though it fits into the block. AERA members are cautioned to verify casting numbers before ordering replacement crankshafts.
Years VIN CODE Casting Number
1991-94 L & 1 4737 or 737
1995 L 2170
1995-2000 K 2170
1995-2000 1 2170
The AERA Technical Committee |
