OK so i was reading a post the other day and someone said you know your fan clutch is bad if your fan doesn't stop immediately after your motor stops.
so i looked at mine and after the motor stooped the fan went around
like 1 to 2 times. is it bad?

 

That sounds about right. With the engine off, try to turn it by hand, you should have resisitance. I just replaced mine because it wasn't turning at all when the engine was running.

 

That was me who said that...just my way of testing it because the turning it by hand method wasn't definitive for me. Sounds like yours might be on it's way out, but not completely bad yet. Let me ask a question, though. Was your engine completely up to operating temp when you shut it off to watch the fan? The reason I ask is that the fan clutch itself needs to be hot for this test to work. The clutch has some kind of silicone-like fluid inside that gradually engages the fan as it gets hotter.

My bad fan clutch would spin probably 3-5 times after engine shutoff and my new one would not even spin 1/2 of a rotation (again, when hot, this is key ). I would replace it if I were you and not wait for it to be completely non-functioning. These 4.0s need all the help they can get when it comes to cooling. Feel the air flow before and after...for mine, it was the difference between a breeze and hurricane force wind!

 

if it doesnt roar like a jet plane when you first start the motor and drive (when the motor is cold from sitting overnight) the clutch is bad.

 

thanks guys. the motor was cold, but i too think its on its way out. it gets parody hot here in summer, so I'm just going to replace it.

 

The fan clutch should slip more when cold than when hot (it never becomes a direct mechanical connection.) I've noted a service life of about five years for the fan clutch, in the XJ.

Once the engine is good and warm, turn it off and try to turn the fan by hand - there should be significant resistance. Alternatively, heat the fan clutch up at the hub with a heat gun or a hair dryer, and then try to spin.

While you should get some resistance when it's cold, it won't be much - and it's not what you're looking to find out.

 

hey there, so I was going through reading reasons my jeep overheats just idling. Going down road even at 25 is fine but not at idle. I seen this post and let my jeep warm up.. when I turned it off I was able to walk around to the front and the fan was STILL spinning for another 4 seconds.. soooooo fan clutch is bad??

 

See my reply to the other thread you started.

 

Buy the OEM MOPAR unit. The Chinese aftermarket stuff does not last from what I have read