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Should Explorer clutch fan always be turning?

mgb0302

Sr. Member
Joined
Jun 29, 2002
Messages
424
I just finished the explorer serpentine swap on my 351 and I noticed the fan is always turning. I am unsure if it is just turing in due to minimal sympathetic force from the water pump. I let it sit for awhile and the engine got up to 210 and it seemed to be spinning at the same speed as it was when I first started it up. Anybody know what temp the clutch is designed for?

Thanks
 

Broncobowsher

Total hack
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Jun 4, 2002
Messages
35,628
It always spins. Just not with much force until warm.
It senses the air temperature coming off the radiator, not the water temperature. Once it gets warm it starts locking up and pulling a lot more air.
 

EPB72

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Jul 13, 2019
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Nope..BUT seen plenty of the plastic ones crack apart at the metal impregnated area,...ford ,gm, toyota,nissan seen them all even less then 10 years old ..
 

73azbronco

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From my research, the plastic fans only lock up to about 80%, the metal ones, which are heavy duty version, lock up to 100%.

They do not move same amount of air if one is slipping 20% of the force it is getting. The heavy duty is the truck version or tow package version, the plastic is a quieter soccer mom version.
 

toddz69

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From my research, the plastic fans only lock up to about 80%, the metal ones, which are heavy duty version, lock up to 100%.

They do not move same amount of air if one is slipping 20% of the force it is getting. The heavy duty is the truck version or tow package version, the plastic is a quieter soccer mom version.

In your research, did you find the different fan clutch PNs for the plastic vs. metal?

Todd Z.
 

56f100bbw

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Good question Todd I have a dodge diesel truck and the aftermarket fan clutch is junk compared to the Mopar factory fan clutch huge difference what brand-name would be a good one for the explorer serpentine metal fan
 

Broncobowsher

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Messages
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I am also questioning the 80% and 100% lockup. The fan clutches I have worked with never lock up 100%. They physically can't, there is no solid connection. I can see someone making that comparison off fan noise. The higher blade count on the plastic should make for a quieter fan.
 

sanndmann3

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From what I have seen, the metal fans were on the earlier explorers (96-98?) and plastic was on the later ones. Could be wrong but that is my recollection...
 

toddz69

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From what I have seen, the metal fans were on the earlier explorers (96-98?) and plastic was on the later ones. Could be wrong but that is my recollection...

You've seen more of these than anyone else! That was my recollection as well. I looked on Rockauto and they show the metal for 96-98 and the plastic overlapping a little bit (97 start, I think) and continuing through 2001.

I must be lucky with my plastic fan - I've had it installed since 2005 with no issues and I drive my truck a lot more than most people do. I can't recall if I used a new or used one when I did the swap - probably new. Maybe people have cracking issues if they re-use junkyard fans?

Todd Z.
 

Quick & Dirty

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Joined
Feb 15, 2004
Messages
845
From the Hayden catalog, thermal fan clutch section;

Standard Duty Thermal
Turns fan 60-70% of shaft speed when engaged.
Disengage to 20-30% of the shaft speed
Used with lighter pitch fans. (1-1/2” of pitch)
Flat plate impeller design with up to 11.4 Sq. In. of working surface.
Identified by a smooth steel faceplate & thermal spring assembly on the front side.

Heavy-Duty Thermal
Turns the fan 70-90% of the shaft speed when engaged for increased cooling.
Turns the fan 25-35% of the shaft speed when disengaged.
Used with deeper pitch fans. (2-1/2” of pitch).
Land and groove design with up to 27 Sq. In. of working surface.
Identified by finned aluminum faceplate and thermal spring on the front.

Severe Duty Thermal
Turns the fan 80-90% of the shaft speed when engaged.
Turns the fan 20-30% of the shaft speed when disengaged.
Used with deeper pitch fans. (2-1/2” of pitch).
Land and groove design with up to 72 Sq. In. of working area.
Larger working surface provides cooler running and longer life expectancy.
Thicker body and deep finned faceplate dissipate more heat.
Can be used in place of many heavy-duty clutches.
 

73azbronco

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In your research, did you find the different fan clutch PNs for the plastic vs. metal?

Todd Z.
Yes, they are different, the screw holes are what do not match up for the blades, search function is not finding thread i Had with part numbers and pics.
 

73azbronco

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I am also questioning the 80% and 100% lockup. The fan clutches I have worked with never lock up 100%. They physically can't, there is no solid connection. I can see someone making that comparison off fan noise. The higher blade count on the plastic should make for a quieter fan.

This is direct from clutch makers website tech info. Like I said I had a thread with all this and now can't find it.
 

73azbronco

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From Hayden website


Standard Duty Fan Clutches
 Standard Duty Fan clutches rotate 60-70% of the shaft speed
when engaged and 20-30% of shaft speed when disengaged
 Standard Duty Fan clutches are recommended for vehicle with
standard use and conditions.
Heavy Duty Fan Clutches
 Heavy Duty Fan Clutches Fan clutches rotate 70-90% of the shaft
speed when engaged and 25-35% of shaft speed when
disengaged
 Heavy Duty Fan clutches are recommended for vehicle with high
or heavy use and harsher conditions.
Severe Duty Fan Clutches
 Severe Duty Fan Clutches Fan clutches rotate 80-90% of the
shaft speed when engaged and 20-30% of shaft speed when
disengaged
 Severe Duty Fan clutches are recommended for vehicle with high
or heavy use and severe conditions.
 Vehicles left at idle for extended periods may fall into the severe
conditions category




So I was off 10% saying 100%:)

I use the severe duty metal blade clutch.
 
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