FORD TYPE 9 GEARBOX REAR OIL SEAL
TYPE 9 GEARBOX REAR OIL SEAL
This seal fits at the rear of the gearbox tail housing where the propshaft fits. It is a proper "rotational" oil seal with oil thrower pattern.
Leaking can be caused by a worn seal, also check your propshaft UJ for wear and nose of propshaft for wear.
The bush / bearing inside the rear tail housing can aslo be worn.