This special lip seal is used on the end plate of certain Titan FF1600 and 2.0L oil pumps designed to accept a bolt-on tachometer drive gearbox.
It fits the Titan FF1600 Oil Pump Tach Drive Mount Cover (formerly Part No. 166-21) and the Titan Series 2 Pump Standard Rear Cover (Part No. 177-53). This seal is included in the Titan Series 2 O-Ring and Seal Kit (Part No. 177-55).
It is not used on FF1600 pumps with a plain cover, or any Series 1 pump for 2.0L engines. It is also not needed when the tach drive is mounted on the front (timing chain) cover on the FF1600 engine.