ROD AS-CONNECTING 2239150 - Caterpillar

3406 (92U),
3406B (7FB, 8TC, 4MG, 5YG, 3ZJ1-15181, 5KJ1-7799, 2EK),
3406C (3ZJ16182-Up, 5KJ7800-Up, 4CK),
3406E (5EK) Truck EnginesReference: Truck Engine News, October 1991, Page 5, "No Gaskets Used With Aluminum Flywheel Housings" on 3406B and 3408 Truck Engines.Truck Engine News, September 1992, Page 1, "New Plug And O-Ring Can Prevent Oil Leakage At The Flywheel Housing Gasket" on 3406B, 3406C And 3408 Truck Engines.
Description of Change: The flywheel housing to cylinder block joint uses a gasket to improve the integrity of the joint. Additional mounting bolts, clip attachment holes, oil baffles and spotfacing under mounting bolts improve the joint reliability. A part service gasket is also available for engines without the extra mounting bolts. Flywheel Housing Gasket
This gasket is a steel core composite design with beading between the upper bolt holes to increase gasket loading in the tongue area of the housing. The 108-5891 Gasket has 5 more (24 total bolts) 3/8 inch mounting bolt holes and requires a cylinder block and flywheel housing with comparable mounting holes. A 105-5082 Gasket (19 total bolts) is for part service to replace the 7N-9335 Gasket or the 1U-8846 Liquid Gasket on engines without the 5 additional holes in the cylinder block and flywheel housing.
Flywheel Housing
The 108-4749, 108-4750, 108-4753, and 108-4754 Flywheel Housings have: * 5 more (24 total bolts) 3/8 inch mounting bolts to provide additional clamping load on the gasket.* 5 tapped 3/8 inch holes for attaching clips or brackets to prevent disturbing the initial tightening torque of the mounting bolts.* Cast oil baffles around the camshaft and the rear main bearing area to reduce the splash oil to the upper housing area.* Spotfacing under all mounting bolts to assure more consistent transfer of bolt torque into bolt clamping load.
Cylinder Block
The new 108-3912 Cylinder Block in 108-3916 Field Replacement Block Group for 3406B and 3406C Truck Engines and the 108-3918 Cylinder Block in 108-2111 Field Replacement Block Group for 3406E Truck Engines has 5 more (24 total bolts) 3/8 inch mounting bolt holes. These 5 mounting holes provide additional clamping load on the gasket. These cylinder blocks also have cast oil baffles around the camshaft and the rear main bearing area to reduce the splash oil to the upper housing area.
Adaptable To: 3406B and 3406C Truck Engines 2EK901-UP, 3ZJ6200-49090, 4CK168-24018, 5KJ7584-8008 and 3406E Truck Engines 5EK1-1384 were built with 1U-8846 sealant and may be serviced with the 105-5082 Flywheel Housing Gasket. Truck Engines built with 108-5891 Flywheel Housing Gasket between the flywheel housing and cylinder block should be serviced with that gasket.
These improvements were phased in over several months. Engines are built with castings changed but bosses not machined. Therefore, engines may have bosses machined or not machined on the cylinder block and a flywheel housing with no bosses or bosses not machined. Conversely, there may be engines with no cylinder block bosses but the flywheel housing with bosses not machined.
The 108-3912 Cylinder Block is effective with 3406C Truck Engines 3ZJ48667, 4CK23678, 5KJ8009. The 108-3918 Cylinder Block is effective with 3406E Truck