Things that go shift in the night

[hull 433]

After running just fine, freely cranking, etc., the Ghost has shifted gear slightly, with all the usual signs - resistance and movement forward while cranking, etc.

Are Fords given to shifts in the night? What might have caused this?

[Norman Kling]

One thing which could cause it would be parking brake needs to be adjusted. Another could be colder weather which could cause oil to get thicker and stick in the high gear clutch. The oil would also cause harder cranking with a cold engine. I like to park with the parking brake forward on a level surface. Then pull it back before starting. You could also jack up one rear wheel to keep it from creeping.
Norm

[TXGOAT2]

One likely cause is cooler weather, which brings thicker oil. If the problem goes away when the engine is warm, it is almost certainly due to seasonal cooler weather. Model Ts do not like thick oil, and for cool and cold weather driving, a 10W20 or even a 5W20 oil will give good results. In an engine in good condition, full synthetic 5W20 or 0W20 will do a good job. Thicker oil or dirty oil will cause the clutch to drag when the engine is cold, making starting more difficult. Model Ts are more sensitive to this effect than most other cars due to their having a multi-disc wet clutch and the flywheel and magnets running in the crankcase oil. Also, the clutch is located behind the transmission rather than ahead of it.

[Jerry VanOoteghem]

Could also be worn lugs in your high speed clutch drum, (a.k.a. brake drum), not allowing clutch discs to release completely. This problem can be intermittent, depending on whether or not the clutch discs get caught up in the lug grooves, or to what extent they do. It might be interesting, and a good test, to rock the car back and forth, to see if any hung up discs can be made to release... if that's indeed the issue.