Re: 1941 Packard 110 - Fan Wobble and Belt Tension

Posted by Lex On 2016/8/12 10:27:57

From what I've seen on a number of old-school trucks, belt-driven fans can handle a remarkable degree of wobble before they get problematic. That said, there's potential for a broken-off blade to punch through the radiator or dent the hood, so the stakes are high. If it's a case of bent blades (versus poorly-distributed weight), you can attach something to the back of the radiator as a distance marker to see how far off each fan blade is. Set the marker to a blade of your choice, then rotate each blade to it and see how far off they are. Blades can then be carefully hand-bent to match the marker. Not as good as professional balancing, but it should reduce the wobble.

According to 26th-series Packard manuals, the belt should be tight enough to rotate the engine when rotating the generator or water pump. To my mind, that seems aggressive, especially with a dry or partially-glazed belt. With a brand-new belt, sure, but realistically, V-belts are not especially sensitive to tension. If you're at the limit of the tensioner arm, I would definitely grab a shorter belt (1-2in shorter should do it), just so you have room to add tension as the belt stretches. Hard to gauge if that 1in of deflection is "about right" without knowing more about the level of force applied.