CTCI Authenticity Chairman
Over the last few months I observed several Thunderbird distributors installed with a gasket or “O” ring between the base and the engine block. All “Y” block distributors are designed to be installed without a seal, They will not leak oil, the distributor base outer tube is machined to fit into the block and seal metal to metal (Aluminum to cast iron).
Some of the engine rebuild kits contain a gasket that is almost the same diameter as the distributor housing lower tube. Inexperienced mechanics occasionally will use the gasket during distributor installation. If this occurs the distributor is held high and the lower distributor drive gear does not mesh properly to the cam shaft gear which drives the distributor. Due to the angle cut of the gears (helix) as the rpm increases the distributor gear is pulled down into the cam shaft drive gear.The downward pull of the distributor drive shaft is then restricted by the gasket. The drive shaft gear then pulls the upper internal parts of the distributor down into the base of the upper distributor housing. If this is allowed to continue the upper housing and internal rotating parts will be severely damaged. If a gasket is in place and the distributor has started to squeak the damage more than likely has occurred and a distributor replacement will be required, which is an expensive situation if it is a tach drive.
Photo # 1- Shows three types of seals that have been found installed on 1955 /56 & 57.
Photo # 2- Shows the seal surface of the distributor which goes into the engine block without a seal of any type..
Photo # 3- Shows the distributor properly installed without any type of seal.