Engine Stay Cable

What is the purpose of that strange cable that connects the bellhousing to the frame at the transmission crossmember? The Parts List calls it a "Cable, engine stay, assembly" and it is found in the Engine Mountings Group. There are all kinds of theories about it's purpose but the name is a clue. Engine Stay Cable - sounds like it makes the engine stay in place.

A 1950 CJ-3A Engine stay cable, transmission crossmember and skid plate.

On page 34 of the Maintenance Manual for Willys Model MC-38 (a military sibling of the CJ-3A) it is explained. Here is what the manual has to say...
"The engine is prevented from moving forward on the rubber mounting, when a sudden stop is made, by the engine stay cable which is attached to the left side of the flywheel bellhousing in the front and to the frame cross member at the rear. The length of the cable is adjustable to provide correct tension through a threaded end mounting. Do not overtighten the cable. It should be adjusted to provide 1/2" up and down movement by thumb pressure."

Engine mounts like this can make you appreciate the purpose of the Stay Cable. One sudden stop and the cooling fan would probably hit the radiator if it wasn't for the cable holding it back.