Method To Restore Worn Cam Gear Thrust Area On
                       Some Engine Blocks

Many late model engines (Chevrolet small block and 6.5L (396
CID), Dodge & Plymouth 3.4L (225 CID), Oldsmobile 4.0 & 4.3L (425
& 455 CID), Buick 4.1L (401 CID) and others) do not have camshaft
thrust washers, but depend upon the mesh of the distributor drive
gear to retain the camshaft.  Often the cam gear or sprocket
causes the front of the block to wear to such an extent that
repair is needed to return the block to service.

A relatively easy yet effective repair is suggested:

     (1) Make a metal brush (similar to a cam bearing drive plug)
     approximately 2 long with the outside diameter to fit the
     cam bearing housing bore.  Provide a slight taper on the
     O.D. to prevent the bushing from going all the way through. 
     Drill an inner hole in the bushing to accept a valve seat
     installation pilot.  Modify a valve seat cutter shank to be
     turned by 1/2 electric drill and attach a cutter head
     proper diameter to match the O.D. of the worn circle.

     (2) Cut the front of the block the depth of a Y91
     Continental main bearing thrust washer.  The O.D. of the
     thrust washer should be machined to press fit in the
     machined counterbore.  The I.D. of the thrust washer should
     be machined to fit freely over the cam bushing.  The Y91
     thrust washer should then be installed.

After tooling up for this operation, the entire procedure should
take no more then five minutes and the only cost is that of the
thrust washer.

NOTE: Depending upon your valve seat equipment, it may be
necessary to change the above tooling to accommodate your
equipment.

                                     The AERA Technical Committee


April 1973 - SPB 18

##END##

                             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

                    Oil Pump Installation On
              1962-81 Chrysler (Plymouth Dodge) V-8
    4.5L, 5.2L, 5.5L & 5.9L (273, 318, 340 & 360 CID) Engines


Improper oil pump installations in the subject engine shave
resulted in serious problems and damage.  When installing the oil
pump, make sure the mounting neck is fully inserted in the
mounting hole in the block and remains fully inserted while
mounting bolts are being installed and fully tightened down.

This is particularly true of the outboard mounting bolt, as the
tendency is to let the pump slide out of position while the bolt
is being installed.  This error causes the pump to be misaligned
in the block and results in fracture of the mounting neck.  this,
in turn, can lead to other serious difficulties such as breakage
of the oil pump hex drive and may eventually cause complete oil
pump failure.

CAUTION:  Be sure that the main cap bolt head next to the oil
pump housing is square with the side of the cap as shown in the
diagram below.

                      (Insert Illustration)


                                     The AERA Technical Committee


April 1984 - SPB 112 

##END##

                          Caution On Crankshaft & Bearing Identification On
                                    Chrysler, Dodge & Plymouth Engines

It has been reported that many of the subject crankshafts are being improperly identified as .020 undersize due to bearings having a marking of AT20.  This marking does not indicate that the bearing or crankshaft is .020 undersize.

The correct bearing sizes other than standard are indicated by markings such as:  .001, .002, etc.  The marking AT20 does indicate the composition of the bearing (aluminum with 20% tin).

Chrysler Corporation will revise the AT20 marking to AT in the future to eliminate this source of misidentification.

                                                                      The AERA Technical Committee

                                                Bearing Knock On
                        Chrysler Products Engines with Air Conditioning

Chrysler, Dodge and Plymouth vehicles equipped with air conditioning may develop a slight bearing knock due to the additional load placed on the front crankshaft main bearing by the drive belts.

The noise is most pronounced at idle, or slightly above idle, with the transmission in gear.  The intensity can be increased or decreased by tightening or loosening the drive belts.  This noise will not cause a bearing failure.  However, should it be necessary to reduce the noise to satisfy a complaint, the condition can be minimized by select fitting of the No. 1 main bearing.  Bearing clearance may be checked with plastigage (range .001 to .003) following the instructions included in the plastigage package.

CAUTION: Plastigage readings are only accurate within the .001 - .003 range specified.

	(Insert Illustrations)

To avoid the noise associated with high belt loads, the No. 1 main bearing clearance should be .001 to .0015.  The clearance can be checked with plastigage in the lower shell if the drive belts remain tight.  (Plastigage instructions mention the weight of the crank will give an erroneous reading if the crank is not supported.)

Fitting The Main Bearing With Plastigage

If the No. 1 main bearing clearance is:

1. Over .0015:  Replace with new standard upper and lower shells.  (Loosen the drive belts to roll out the upper bearing shell.)

2. With new shells; still over .0015 but less than .0018:  Install one .001 undersize shell (upper or lower) and recheck clearance.

3. Over .0018 but less than .0025:  Install .001 undersize upper and lower shells and recheck.


	The AERA Technical Committee

                           Valve Crosshead To Rocker Lever Clearance On
                              NH, NT & V-1710 Series Cummins Engines

Valve crosshead nose to rocker lever clearance on the subject engines must be checked during engine rebuild and at any time valve crossheads are replaced on engines using crossheads No. 123416 & 3000326. A minimum of .020 (.51 mm) clearance must be present as illustrated in Fig. 1, on the cylinder being checked with valves completely closed and crosshead in the upmost position. After installing rocker lever assemblies, check crosshead to rocker lever clearance as follows:

1. Turn crankshaft slowly in direction of rotation until the valves are closed on the cylinder being checked. With rocker lever held firmly against the stellite pad of the crosshead, a .020 (.51 mm) wire type feeler gauge must pass between the crosshead nose and the lower beam section of the rocker lever.

2. If the feeler gauge does not pass through:

a. Remove the rocker lever and/or crosshead and grind the nose of the crosshead or 	rocker lever beam in the area circled in Fig. 1 until enough clearance is obtained.

b. If the rocker is ground, grinding should cover the complete area illustrated in Fig. 2 in a continuous arc. Do NOT grind just the contact area.

Caution: A sharp depression in this area will cause a stress riser and eventual failure of the lever. Grind only enough material to achieve the required clearance. If grinding enters the oil passage, the rocker lever must be junked.

c. Grind sharp edges smooth.




                                                                   The AERA Technical Committee