Mech fan

[Black Betty]

I finally got around to getting my yj on the road, and driving it around I noticed that the fan doesn't seem to disengage at all, no matter what rpm I hit.

Does the clutch assembly on these activate based on temp or rpm?  Is this a common problem with the 4 l?  I don't seem to notice the same thing on my 99 Cherokee.

Thanks in advance.

[hps4evr]

clutch fans are kinda like a viscous coupling. so the fan should pul more air when the engine is hot and not so much when its cool. the details on why are long forgotten by myself. im sure a search on the internet would find the details. they do wear out though. the fluid can leak and the fan seizes solid (kinda like what you're getting on yours). or they dont grab enough and spin freely and dont pull enough air. i havent seen them fail that often. but they do. they dont seem to be too pricey and pretty easy to change out. even a used one from the wrecker is probably fine.
or the other option is to go electric. less drag on engine but they are more complicated and will fail eventually.

[Black Betty]

Thanks man, kinda figured.  Did a search on the old interweb but didn't come up with much luck.  Probably will just replace the whole clutch, sound is getting annoying, sounds like a transport driving around.