B5.9G, B5.9LPG – Troubleshooting and Repair Manual – 001-033   Gear Housing, Front

Troubleshooting the front gear housing and gear train consists of checking for leaks at the gaskets (front cover) and the front crankshaft lubricating oil seal, inspecting the gears, and measuring backlash when required.

Replace the front crankshaft oil seal. Refer to Procedure 001-023.

Gear noise emitted from the cover can indicate worn gear teeth.

NOTE: Excessive backlash can affect engine timing and engine performance.

The gear train consists of the crankshaft gear (1), the lubricating oil pump gear (2), the idler gear (3), the camshaft gear (4), and the accessory drive gear (6), if used.

The gear housing provides a support for the fuel housing and the accessory drive gear, if used.

Replacement of the gear housing or the timing pin assembly necessitates a realignment of the pin assembly on the housing to correspond to top dead center for cylinder number 1. Refer to Procedure 001-013.

• Remove the rocker lever covers. Refer to Procedure 003-011.
• Remove the rocker levers. Refer to Procedure 003-008.
• Remove the push tubes. Refer to Procedure 004-014.
• Remove the vibration damper. Refer to Procedure 001-052.
• Remove the camshaft. Refer to Procedure 001-008.
• Remove the fuel control housing. Refer to Procedure 001-008.

Remove the six front oil pan capscrews.

Remove the gear housing capscrews.

Using a metal scraper, attempt to separate the lubricating oil pan gasket from the gear housing.

Remove the gear housing by slightly tapping on the housing with a plastic hammer.

Clean the gasket material from the cylinder block.

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

Use solvent and a nylon brush to clean the oil drillings.

Dry the front gear housing with compressed air.

Inspect the front gear housing for cracks or damaged sealing surfaces.

NOTE: If the front gear housing is cracked at the accessory drive hole, double-check the accessory/air compressor installation practices.

If the fuel housing studs are damaged or are being installed in a new housing, coat the threads with a thread lock such as Loctite 242. Use two nuts locked together to remove and install the studs.

If the gear housing is being replaced, remove the engine dataplate and install it on the new gear housing. Refer to Procedure 001-057.

If the pan gasket is torn, it can be repaired. Cut the torn gasket off so that it is even with the front of the cylinder block.

Using the old gasket as a pattern, cut the front section of a new gasket to the same size.

Three-Bond™ Sealant, Part Number 3823494

Clean the sealing surfaces and coat the new gasket on both sides with Three-Bond™ 1207-C sealant, Part Number 3823494, or equivalent.

Mark and trim 1.59 mm [1/16 in] off the new gear housing gasket.

NOTE: When properly trimmed, the gear housing gasket should be even with the lubricating oil pan gasket when installed.

Position the gasket on the alignment dowels.

Use guide pins (M8 x 1.25 x 50) to assist in aligning the gasket and gear housing. Be sure to remove the guide pins after alignment.

Carefully install the gear housing, making sure both gaskets are in place.

Start the oil pan capscrews in the holes not being used to tie the gasket in place.

Install the remaining two capscrews and tighten.