I'm reassembling my motor after a full rebuild (spun bearing) and am trying to determine if my fan clutch is bad. It takes about as much torque as opening a new jar of spaghetti sauce to turn the drive plate while holding the fan still. Is this normal, or is the fan clutch frozen. It's about 55 degrees here. Thanks.

Sounds about normal. The real test is while it is running.

Does it dis-engage when cold?
Does it engage when hot?

Does the bearing have any play in it? If so, replace it.

If it's bad, might I direct you to the classifieds here.... SOMEONE has a fan and clutch for sale...

A clutch fan is supposed to have some resistance when you try to turn it by hand. If its too smooth and easy to push than it too hard. But i guess temperature can also take its toll. Only way is just to turn it on and find out.

It Depends on its position, but yes, a jar of spahgetti sounds right. When its face down that thick silicon will be resistant to turning. Its not the same as it heats up & spun.......

When I replaced my dead one two summers ago, I had the new one and the old one on the garden wall next to each other. The resistance to turning was identical--spaghetti jar is too stiff a description, but it was 90°F then. So yours could still be bad--or good. The roar on start-up that goes away is the best indicator, in my opinion, of a healthy clutch. I agree there is no way to be sure off the truck.