CTCI Authenticity Chairman
I will quote a statement that I have heard from several 1955/56/57 Thunderbird owners.
“I have a squealing noise coming from the front of my engine. I have checked the belts and they are ok.”
In most cases it turns out to be the balancer on the crankshaft pulley. Over time the rubber sleeve between the balance weight and the crankshaft pulley assembly has slipped allowing the balance weight to slide back toward the engine. Once it slides rearward approximately 3/4″, it contacts the front motor mount, that’s when the squeak starts. If left unattended the balance weight will wear into the front engine mount and the outer rear edge of the balance weight will wear down.
Image 1 shows a normal balance weight properly positioned on the left, the balance weight on the right has slipped rearward approximately one inch and has worn into the front motor mount.
Image 2 shows the wear on the front motor mount after the balance weight slides to the rear and makes contact.
Image 3 shows the wear on the back edge of the balance weight after it wears into the front motor mount.
All Thunderbird parts dealers have an exchange service for worn crank pulleys or check with the DamperDoctor at damperdoctor.com.
Image 4 shows different wear on the crank pulley shaft. After years of use with the timing cover seal contacting the shaft it will wear a groove. This condition is not related to the slippage of the balance weight. It should be addressed when the crank pulley is removed for any reason. Repair instructions and the part number for a stainless repair sleeve can be found on page 390 of the restoration manual.