30U trans gears

[GWR]

Thanks everyone. Yes according to my parts book the Q, U, and 30U had the original Sliding Gear type - spur gears transmission. The PA had a "Easy shift or Silent Second" spur gear - free wheeling. Maybe your right, there doesn't appear to be any metal fibers in the oil, maybe I just drive it.

Happy Motoring,  Gary

[Doug]

Hey, It's a 70 year old car, Drive it and injoy it.

[12905]

The early transmissions - at least until the early 'Thirties - used spur cut gears (teeth parallel to the gear axial centre line). These are always noisy even when brand new. Helical cut gears were developed - depending on the source of the opinion - either specifically to cut out the whine with the side benefit of being able to transmit much more torque - or vice versa. The design is so successful that helical gears remain basically unchanged today.

There is no whine in 3rd gear because it is direct drive with no torque transmitted from the input shaft (driver) to the countershaft (driven) or any other gearset.

[TodFitch]

I'm not 110% sure but didn't those old transmissions have square cut gears throughout and didn't they whine because of it? They didn't start to bevel the tops of the gears in second until maybe the middle of the 30s. They called it 'Silent Second'. Third gear always was beveled to stop whining and I think 1st was quieted down by the end of the 30s.

The 1933 Plymouths had spiral cut gears with a "silent second". It has sliding "dog clutches" to engage second and third but no synchronizers. In general I agree with your chronology but think you should rephrase that "middle of the 30s" to a bit earlier.

I'd have to check my reference information to see if the PA and PB transmissions had spiral cut gears but I think they might. I'd be a little surprised if the Q, U or 30-U had it though.

[FourDoor]

I'm not 110% sure but didn't those old transmissions have square cut gears throughout and didn't they whine because of it? They didn't start to bevel the tops of the gears in second until maybe the middle of the 30s. They called it 'Silent Second'. Third gear always was beveled to stop whining and I think 1st was quieted down by the end of the 30s.

[GWR]

I have three transmissions and they all whine the same in first and second gears. "Anyone have any ideas where I could find good gears, or how to uiet these down some.
Sure would be nice to drive through the shows without everyone looking at you (because of the noise).

Gary