Fan Clutch on 06 KJ with Tow Package?

[feetwet]

Noob owner of an 06 Sport 4x4 with the tow package. The fan noise from the Boeing 737 cooling fan makes me wonder how much power this fan might be sucking unnecessarily.

Does anyone know if the fan clutch on these is thermal activated, or just rpm based. What is the temp or RPM rating for it to start "slipping".

Fan reminds me of the old hot-rodder "flex" fans that mounted solid to the pulley and used no clutch.

 

[GoldBug]

I've never noticed the noise on mine.

 

[Marlon_JB2]

Believe me, the noise is there. It's a huge whooooooooshing noise. If you compare a Liberty with and without, you'll definitely notice it.

IMO, the Liberty sounds quite boring without the noise.

 

[GoldBug]

maybe the liby is just sooooooo much quieter than my TJ i don't notice.