by Roy Berndt

I have a La-Z-Boy recliner that I probably should have retired ten years ago. Yet even today, it’s one of the most comfortable chairs that I have ever sat in. Because I hate the thought of giving it up, my next move will be to put it in the garage, where I always have TV, tunes and a fridge for those times that I have to get out to the garage and tinker (that is “guy code” for those that didn’t get it).

Well, that time has come for an engine that is considered one of the best off-road engines ever made. The extreme low end torque is ideal for trailing and rock crawling but “no mas” for the 4.0L Jeep. 2006 is the end of U.S. application production.

The Wrangler TJ is being replaced with the new JK design with the 3.8L V6 Chrysler engine. It appears likely that the 4.0L engine may be made for many years to come in China, however, since there is still current production of a modified version of the XJ using both the 2.5L and 4.0L engines.

I can’t think of a better way to say good-bye to this old friend than with a recap of its five “C’s”: cylinder block, crankshaft, camshafts, cylinder head, and connecting rod.

Cylinder Blocks

1987-1990

C/N 8933002665, 53005535

Cast iron block, left side may have three 2″ or two 1″ cast plugs. Second bolt from pan rail on right side of timing cover is a threaded bolt hole. Oil filter mounting on left side of block is pointing downward.

1991-1995

C/N 53008405

Cast iron block, left side has five 2″ cast plugs. Second bolt from pan rail on right side of timing cover is a through hole. Oil filter mounting on left side of block is pointing downward. The upper (block side) bearing-locating tab was moved to the center of the bearing register. Two additional bolt bosses added to block where fuel pump would sit (lower right front) for coil mount.

1996-1998

C/N 3010341, 53010449

Cast iron block, left side has five 2″ cast plugs. Second bolt from pan rail on right side of timing cover is a through hole, coil mount bosses lower right front. Basically it is the same as the 1991-’95 blocks except for dowel pins in the deck for head and block alignment. Oil filter mounting on left side of block is pointing downward. Uses long main bolts and stud girdle. Has “NVH” on side to denote block strengthened for “noise, vibration and harshness” reductions (no visible differences).

1998

C/N 53020514, 53020515

Cast iron block, oil filter mounting surface is 90° to pan rail of engine instead of pointing downward. Uses long main bolts and stud girdle. Has 1/8? pipe thread oil tap into main oil line in rear of block. Will retro back with filter kit available from Daimler-Chrysler. Has “NVH” on side to denote block strengthened for “noise, vibration and harshness.” Grand Cherokee application.

1999-2006

C/N 53010327AB, 53010328AB

Cast iron block, oil filter mounting surface is 90° to pan rail of engine instead of pointing downward. All kinds of configuration and boss changes with long mounting boss protruding off the lower left of block. Uses long main bolts and stud girdle. Camshaft thrust plate block. Has “NVH” on side to denote block strengthened for “noise, vibration and harshness.” No coil pack mount bosses, now mounted on cylinder head.

1999-2001

C/N 53010449AA

Cast iron block, second bolt from pan rail on right side of timing cover is a through hole. Oil filter mounting on left side of block is pointing downward. Uses long main bolts and stud girdle. Basically the same as 1996-1998 except that it is a camshaft thrust plate block. Has “NVH” on side to denote block strengthened for “noise, vibration and harshness.”

Crankshafts

1987-1991

C/N 3003453
This application uses the old style AMC pilot bushing p/n 33004041. Hole for converter hub machined to .550″ depth. May also have hub hole depth of .850″ using bearing and sleeve assembly p/n 53009180. Caution: this crankshaft can have either .550″ or .850″ pilot hole. Standard transmission must have .550″ pilot hole, can interchange .850″ pilot hole crank for automatic transmission. Best information indicates that .550″ depth crank has knurled rear seal surface.

1992-1994

C/N 3003453

Cast iron crankshaft that has a .850″ rear pilot hole. Caution: this shaft can have either .550″ or .850″ pilot hole. For standard transmission applications a sleeve and bearing assembly p/n 53009180 is required. The pilot bushing is available separately as p/n 53009181. Can be used for 1987-1991 applications only if the pilot bushing housing bore is drilled out from 1.005″ to 1.055″. Best information is that .850″ depth crank has smooth rear seal surface

1995

C/N 53020767

Cast iron crankshaft which has a .850″ rear pilot hole. This shaft is the forerunner to the 1996-2006 shaft with a shorter casting lug at the outer most edge of the rod throw to clear the stud girdle used 1996 and later. Will interchange for 1992-1994.

1996-2006

C/N 53020767, 53020767

Cast iron crankshaft which has a .850″ rear pilot hole. This shaft has a shorter casting lug at the outer most edge of the rod throw to clear the stud girdle used 1996 and later. Will interchange back for 1992-1995.

Camshafts

1987-1995

C/N 8933002893

Cast iron hydraulic lifter camshaft for flat type lifter.

1996-1998

C/N 53020436

Cast iron hydraulic lifter camshaft for flat type lifter. Slightly different grind and used with light pressure springs. This cam will retro back for 1987-1995

1999-2006

C/N 53010397

Cast iron hydraulic lifter camshaft for flat type lifter. This is a thrust plate style camshaft.

Connecting Rods

1987-1995

C/N 205, 2670, 288, 296, 351, 544

Forged connecting rod, Center-to-Center length is 6.127″ with a .931″ diameter pin. Casting number 544 is the most common number seen.

1996-2001

C/N 691

Forged connecting rod, Center-to-Center length is 6.127″ with a .931″ diameter pin. It will retro back for 1987-1995.
1999-2006

C/N 548

Forged connecting rod, Center-to-Center length is 6.127? with a .931? diameter pin. It has a slightly different shaped beam but weighs the same as all the other rods. The assumption is that these rods will retro for all applications.

Cylinder Heads

1987-1990

C/N 2686

Cast iron cylinder head has half circle relief on top of each intake port toward the front of the engine for injector clearance. Has “D” shape exhaust ports that face back to back.

1991-1995

C/N 7120, 33007119

Cast iron cylinder head has a much shallower riser on the front of the intake port than 1987-1990. The exhaust ports are now rectangular shaped with rounded corners.

1996-1999

C/N 0630

Cast iron cylinder head that has two receiver holes on each end of the deck face for block that now uses dowel pins. The intake ports have been changed once again, and there is a new designed rocker cover and gasket that will not retro. This head also uses a lighter pressure valve spring that is beehive shaped.

1999-2006

C/N 0331

Cast iron cylinder head that has two receiver holes on each end of the deck face for the block dowel pins. Once again the intake and exhaust ports have changed and closely resemble 1996-1999. The interior of these ports is very rough almost semi-finished looking. There are now four bolt bosses for the coil pack bracket on the spark plug side of the cylinder head.

So there you have it: a tribute to what once was and will be no more, unless you’re a 4WD enthusiast in China. Also see the April 2003 edition of “Core Corner” (Engine Builder, page 19) for additional details. For greater detail and digital imagery of all the 4.0L changes, electronic Bill of Materials and building specifications, check out the resources available at

www.EngineDataSource.com.

For technical questions, contact the Production Engine Remanufacturers Association (PERA) at: [email protected]