Revised Cylinder Head Gasket & Retorque Procedure 
            on 1981-88 Saab 900 & 9000 Series Engines


Saab-Scania of America has released a new cylinder head gasket and installation procedure for all 1981-88 Saab 900 & 1986-88 Saab 9000 series engines.  This new procedure applies to 8 and 16 valve cylinder head engines produced after 1981.

The revised cylinder head gasket no longer requires retorquing of the cylinder head bolts after the engine has been started and warmed up for the first time.  Furthermore, retorquing of the cylinder head bolts after the first 1000 miles of service has also been eliminated.

Use the following chart to determine if the cylinder head needs to be retorqued:
 
        Engine Series                           Part Number *               Procedure

 1981-88 900 Series 8-Valve            75-85-037                   do not retorque
 1981-88 900 Series 16-Valve          75-61-301                   do not retorque
 1986-88 9000 Series 16-Valve        75-61-301                   do not retorque

  before 1981 900 Series 8-Valve    75-05-217                        retorque
  before 1981 900 Series 16-Valve  75-16-529                        retorque

* Saab-Scania cylinder head gasket part number

Engines manufactured before 1981, using head gasket part #75-05-217 or #75-16-529, must be retorqued as before.


                                     The AERA Technical Committee

                                              Abnormal Combustion On
                                       Saab 2.0L B201 & B202 Engines 

AERA members have reported engine damage from abnormal combustion in Saab automobiles equipped with the 2.0L B201 and B202 engines. The resulting damage has ranged from premature head gasket failure to piston damage shortly after remanufacture of the engine.

After machining the deck surface of the cylinder head, it is important to chamfer the combustion chamber edges.  If left unchamfered, the sharp edges may act as a heat sink during the normal combustion process and start to glow.  This glowing or hot spot may increase the possibility of abnormal combustion, in
particular premature ignition of the air/fuel mixture, leading to a component failure.

Removing burrs, nicks and sharp edges from the combustion chamber
will result in longer engine service.

                                                                        The AERA Technical Committee

                                    Excessive Oil Consumption On
                                 1986-94 Saab 2.0L DOHC Engines

AERA members have reported excessive oil consumption on 1986-94 Saab
2.0L DOHC engines.  The source of this oil consumption has been traced to the engine's positive crankcase ventilation system (PCV).  Apparently the original camshaft cover allows excessive amounts of oil to enter into the induction system.   

A modification was made to the camshaft cover Part #8788135 during the 1994 production year to reduce the amount of oil mist reaching the PCV system.  The part number for the cover, however, did not change.  The identification of the revised cover, requires removing it from the head and inspecting it for the additional tube shown in the illustration below.

                                                                    The AERA Technical Committee

                 Import Engine Bearing Problems

The addition of many aftermarket main bearing sets for import automotive engine applications has caused a frequent complaint that the thrust bearings cannot be installed.

The reason is that in most import engine applications, the flanged bearing length is increased with the undersize of the bearing.  This means those grinding the crankshaft must grind the thrust face of the crank to accommodate the increased bearing length and secure proper clearance of the crankshaft end thrust.

A typical example may be found with the 1.5L and 1.7L Saab engine utilizing a common aftermarket main bearing set:

The .010 undersize is .004 oversize length.  
The .020 and .030 undersize has a .010 oversize length and 
the .040 undersize has a .020 oversize length.

                                                                            The AERA Technical Committee

                            Flywheel Specifications for Case/IH Tractors

The following chart of new flywheel specifications may be used when surfacing or machining flywheels on Case/IH agricultural and industrial tractors.

Engine    Machine Application       Dim. A                 Dim. B

C-60      Cub, Lo-Boy                         1.625                 0.013
C-123     200, 230, 240 Tractors        1.182                 1.188
C-123     Flywheel #372436R11         1.375                 1.188
C-123     Flywheel #635094R11         1.425                 1.125
C-135     330, 340 Tractors                 1.115                 1.188
C-135     404 Tractor                           1.182                 1.188
C-135     T & TC5 w/CRPTCO             1.425                1.125
BC-144    B-414, 3414 Tractors          1.156                 1.334
BC-144    Flywheel #3047594             2.075                  N/A
BD-144    B-275 Tractor                      1.188                 1.313
C-146     660, 770, 780 Sprayer           0.872                0.800
C-146     424 Tractor                            1.293                1.344
C-146     500 Crawler, single plate     2.050                 N/A
C-146     500 Crawler, dual plate        1.425                 1.125
C-153     504, 2504, 3514 Tractors      1.115                 1.188
C-153     444, 2444, 4000 Forklift         1.293                 1.344
BD-154    B-414 Tractor                       1.156                 1.344
D-155     500C Crawler                        3.216                  N/A
C-157     454, 2400 Tractors               2.000                  1.443
D-166     330, 340 Tractors                 1.115                  1.188
C-169     300 Tractor                           1.187                  1.187
C-175     300, 350 Tractors                 1,187                  1.187
C-175     3514 Tractor                        2.719                   1.188
C-175     454, 464, 2400 Tractors      2.000                   1.443
D-179     454, 484 Tractors                2.494                   1.443
D-188     504, 2504, 3514 Tractors    1.115                   1.188
C-200     544, 2544, 8000 Forklift       2.719                   1.188
C-200     3500 Series A                      2.000                   1.443
          S/N 28344 & above
C-200     574, 674, 2500, 3500 Series A   2.808            1.443
          S/N 28343 & below
C-221     460, 606, 2606, 3616 Tractors   2.719            1.188

C-221     3616 Tractor S/N 49943 & above 2.470        1.437
D-236     460, 606, 2606,                      2.719                 1.188
          3616 S/N 1772 & below
D-236     3616 S/N 1773 & above       2.470                 1.437
D-239     574, 2544, 3544 Tractors      2.460                 1.181
D-239     574, 674, 2500, 3500 Tractors 2.494              1.443
D-239     Flywheel #3144211R91        2.204                  1.437
C-248     M, 6 Series Tractors            1.374                  1.406
C-263     506, 560, 606 Tractors          3.032                  1.406
C-263     706, 2706 Tractors                1.624                  1.406
C-263     656 Tractor                            2.470                  1.437
C-264     Super M, 400 Tractors          1.374                  1.406
D-264     Super MD, 400 Tractors       1.374                  1.406
C-281     400, 450, Super M, Super 6  1.374                  1.406
D-282     560 Tractor                            3.031                  1.406
D-282     660, 706, 2706 Tractors        1.729                  1.406
D-282     656 Tractor                            2.470                  1.437
C-291     666 Tractor                            2.470                  1.437
C-291     9000 Forklift                           1.694                  0.120
C-301     806, 826, 856 Tractors          1.624                  1.406
D-310     706, 756 Tractors                  2.362                  1.406
D-312     666 Gradall                           3.063                   1.437
C-335     W-9, WR-9, WR-9S               1.625                   .500 above
          S/N 501-1439                                                   backplate mounting
C-335     W-9, WR-9, WR-9S               1.625                   1.438
          S/N 1440 & up                       
D-335     WD-9                                      1.625                  .500 above
          S/N 501-1439                                                   backplate mounting
D-335     WD-9                                     1.655                    1.438
          S/N 1440 & up 
C-350     W-9, WR-9, WR-9S,              1.655                    1.438
          600, 650 Tractors
D-350     Super WD9, 600, 650 Tractors 1.655               1.438
D-358     826, 2826 Tractors             2.362                       1.406
D-360     766 Tractor                         1.594                       1.406
D-361     806, 2806 Tractors             1.594                       1.406
DT-361    1206, 21206 Tractors       1.562                        1.938
DT-407    1256, 456, Tractors          1.562                        1.938
                 21256, 21456
DT-407    856, 2856 Tractors           1.594                       1.406
DT-414    966 Tractor                        1.594                      1.406
DT-414    1096 Tractor                      1.562                      1.938
DT-414    815, 915 Tractors              1.562                      1.406
DT-429    4100, 4156                         1.562                       1.938
DT-436    1466 Tractor                      1.562                      1.938                                   
DT-466    4366 Tractor                      1.627                       1.938
DV-550    1468, 1568 Tractors          1.792                       1.938
DV-800    4568, max. stock removal .063 1.437             2.938

Specification `A' is measured from the crankshaft mounting flange surface to the clutch friction surface.  Specification `B' is measured from the pressure plate mounting surface to the clutch friction surface.

                                                                      The AERA Technical Committee

                                            Revised Cylinder Head On
                                             Saab 2.0L DOHC Engines

The AERA Technical Committee advises members of a design change on
Saab 2.0L DOHC engines.  Previously this engine used an external oil system feed to the cylinder head.  This design changed to an internal function beginning with engine #J0825B6 in mid 1988.  The affects of this change have reduced the number of locations for possible external oil leaks as well as shortening repair times.

This new head design can be retrofit on all previous engines and is available under Part #7586142, without valves.  All cylinder head specifications and mounting parts are still shared, excluding the external oiling tubes and fittings.  There are three external pipe plugs (Part #8123143) that also need to be installed on the new head.

Saab recommends pressurizing the oiling system before the first engine start-up when this new head is used.
                                         
                                                                         The AERA Technical Committee

                                      New Cylinder Liner O-Ring Seals On
                                      Cummins NH/NT 6 Cylinder Engines

Cummins Engine Company has released new O-ring seals for the cylinder liners in NH/NT 6 cylinder engines.  The new seals are made of an EP material and have a smaller diameter cross-section.

The new seal replaces both the old center seal #3008998 and the old lower seal #183049.  The new seal carries Cummins part #3032874 and is black in color with one blue dot.

The new O-ring seals are not to be intermixed with the former seals on the same liner.  Cylinder liner deformation will result.  You can use the former seals and new seals in the same engine as long as they are used in the correct combinations on each liner.  The illustration below shows the correct combinations.

                                                                       The AERA Technical Committee

                                               Oil in Cooling System on
                                         VW 1.5L & 1.6L Diesel Engines

AERA members have reported instances of engine oil in the cooling system on VW 1.5L diesel engines.  According to AERA sources, the problem is related to a crack in the cylinder head bolt hole located near the oil gallery feeding the cylinder head.

The oil feed gallery in the block is located on one side of the center head bolt hole and a coolant jacket is on the opposite side of the bolt hole.  Pressurized engine oil is diverted through a slot in the head gasket and is feed up the side of the head bolt to the cylinder head.  The oil also follows the bolt back down to the bottom of the bolt hole.  Should the crack in the head bolt hole extend to the coolant jacket, oil can mix with engine coolant.

This problem is generally found on engines equipped with 11mm head bolt holes.  Later design engines utilize 12mm head bolts and do not exhibit this defect.  At the time of this writing no successful repair procedure is available.

                                                                       The AERA Technical Committee