My 308 leaks oil and now I know why

If you read my previous threads you can see I have been chasing my tail on a phantom oil leak. I have had my bell housing off three times and I guess the third time’s the charm.

What I found is there is an oil seal in the bell housing itself. The part is item #21 (part number 116314) on Ferraris parts page #TAV 23.

What it appears had happened is that someone changed out the clutch and did not properly tighten the locking nut that is on the end of the clutch output shaft. Since the nut did not have proper torque to hold the bearings together, the shaft was allowed to play in and out causing the shaft to rub against the flange/bearing housing located on the inside of the bell housing causing metal filings to damage the oil seal that’s located in the same area.

The flange that houses this seal has a small weep hole, so when the seal leaks, gear oil will flow out and drain out of the same hole as the engines real seal would drain out of (which causes the confusion that the engine is leaking the oil) that is located at the bottom of the bell housing. This bell housing oil seal is under some positive oil pressure, since the bearing has a gernal that feeds gear oil into the two bearings located in that top area of the bell housing. So a large amount of gear oil will collect in the bottom of the bell housing very quickly allowing the flywheel to catch it and fling it out of all the bell housing vent holes and quickly making a mess of the engine compartment. I noticed everything from upper cam seals, distributors seals, rear axle and the exhaust header gets oil soaked (the oil burns off the header making more of a mess and smell under the hood).

Concerning Gear oil level: Remember it is very important to top up the gear oil from the rear of the car and put the plug back in the trans axle and then to add the remainder few ounces into the top of the bell housing plug (the cover that has the three gears has a plug on top). Without this little added oil it is possible that oil will not reach and lubricate the top two bearings. These instructions are mentioned in the cars owner’s manual with the amounts and locations of the plugs.

I hope this has been helpful and not confusing. Shoot me an email if you need more help.