Fan Clutch
#1
Racer
Thread Starter
Fan Clutch
My old fan clutch was worn. It had a little play in the hub, it leaked a little, and it continued to spin for a few seconds after I shut off the engine. The car never overheated, but the fan clutch was obviously worn.
Anyway, I changed it to a new one, and now the car sounds like a Cessna 152 when I rev it above 3000 rpm! I can definitely hear the fan roaring when I rev the motor. Is this normal? Can I change to a flatter pitch fan to quiet it down. Like I said, even with the worn clutch, the car ran very cool. Thanks, Fellas!
Temvette72
Anyway, I changed it to a new one, and now the car sounds like a Cessna 152 when I rev it above 3000 rpm! I can definitely hear the fan roaring when I rev the motor. Is this normal? Can I change to a flatter pitch fan to quiet it down. Like I said, even with the worn clutch, the car ran very cool. Thanks, Fellas!
Temvette72
#2
My old fan clutch was worn. It had a little play in the hub, it leaked a little, and it continued to spin for a few seconds after I shut off the engine. The car never overheated, but the fan clutch was obviously worn.
Anyway, I changed it to a new one, and now the car sounds like a Cessna 152 when I rev it above 3000 rpm! I can definitely hear the fan roaring when I rev the motor. Is this normal? Can I change to a flatter pitch fan to quiet it down. Like I said, even with the worn clutch, the car ran very cool. Thanks, Fellas!
Temvette72
Anyway, I changed it to a new one, and now the car sounds like a Cessna 152 when I rev it above 3000 rpm! I can definitely hear the fan roaring when I rev the motor. Is this normal? Can I change to a flatter pitch fan to quiet it down. Like I said, even with the worn clutch, the car ran very cool. Thanks, Fellas!
Temvette72
I have the same noise with mine. 74w/350. I think it just goes with being new. Only time will tell. glassman74
#3
Melting Slicks
Just replaced my fan clutch about 6 weeks ago. I don't hear any additional noises, even abouve 3500 rpms. When the engine is cold, the fan turns (after I turn the engine off) about 1 1/2 turns....when the engine is hot and I turn it off, the fan just stops turning. FYI
#4
Race Director
What kind of fan clutch did you buy,was it a thermostatic type ? It should not roar when its cold except for the first few seconds until the silicone heats up.
#5
Racer
Thread Starter
It's thermostatic. I installed it when the engine was quite warm and took it out for a test immediately. I will let the car cold soak and see how it behaves.
Thanks,
Temvette72
Thanks,
Temvette72
#6
Drifting
Very same thing happened to me, except on my 65 Buick Riviera. Replaced a bad fan clutch and I thought I was behind the stick of an F-16 !! drove it like that for a couple of months and yanked it off, sent the old one out to be rebuilt, put it back on and never heard a peep out of that ole nailhead again.
Never did figure out what made that new clutch sound so loud.
Never did figure out what made that new clutch sound so loud.
#7
Le Mans Master
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Check & see if the fan still spins a turn or two at shutoff. When my original fan clutch went south it locked up solid. I was on the interstate when it happened and the roar that started up really got my attention...
#8
Racer
Thread Starter
I was told that if it turned after the engine was shut off more than just a little bit that it had to be replaced. My old one spun down for 2 or three seconds after I shut it off. The new one stops spinning almost immediately. It doesn't matter if it's hot or cold.
Temvette72
Temvette72
#10
Racer
Thread Starter
It actually makes mine sound like a UPS truck....A nice sound when you're waiting for parts, but not so nice otherwise! I swapped back to my old one. I am going to see if they carry a non-thermostatic clutch at my parts house. Hopefully, that will be quieter.
Temvette72
Temvette72
#11
Race Director
It actually makes mine sound like a UPS truck....A nice sound when you're waiting for parts, but not so nice otherwise! I swapped back to my old one. I am going to see if they carry a non-thermostatic clutch at my parts house. Hopefully, that will be quieter.
Temvette72
Temvette72
#13
Race Director
The thermo type usually has a coiled spring on the front towards the radiator. The non therm doesnt have anything on the front side,its just plain/flat.
Here is some info on different clutches.
Non-Thermal Fan Clutch
• Low cost alternative for some standard thermal clutches.
• Always engaged, less fuel savings than a thermal clutch.
• Spins at about 30-60% of the water pump speed.
• Shorter life expectancy.
• Cannot replace a heavy-duty clutch.
• Identified by the smooth, steel faceplate, (without a thermal spring assembly), on the front.
Thermal Fan Clutch
• Varies the fan speed with temperature of the air behind the radiator.
• Engaged (high speed) operation provides maximum cooling.
• Disengaged (low speed) operation provides fuel savings and noise reduction.
• Greater life expectancy than a non-thermal clutch.
• Briefly engaged at cold start-up.
• Engages at about 170° radiator air temperature, (about 30° lower than coolant temperature).
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 11.4 Sq. In. of working surface.
• Identified by a smooth steel faceplate & thermal spring assembly on the front side.
Heavy-Duty Thermal ….. Corvette AZ GM # 372502
• Turns the fan 80-90% of the shaft speed when engaged for increased cooling.
• 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 26.0 Sq. In. of working area allows higher operating RPM’s.
• Identified by finned aluminum faceplate and thermal spring on the front.
Severe Duty Thermal …..Corvette AX old-GM # 343721 new-GM # 88961768
• 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 70 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.
Here is a link to the full page.
http://www.haydenauto.com/Featured%2...s/Content.aspx
Here is some info on different clutches.
Non-Thermal Fan Clutch
• Low cost alternative for some standard thermal clutches.
• Always engaged, less fuel savings than a thermal clutch.
• Spins at about 30-60% of the water pump speed.
• Shorter life expectancy.
• Cannot replace a heavy-duty clutch.
• Identified by the smooth, steel faceplate, (without a thermal spring assembly), on the front.
Thermal Fan Clutch
• Varies the fan speed with temperature of the air behind the radiator.
• Engaged (high speed) operation provides maximum cooling.
• Disengaged (low speed) operation provides fuel savings and noise reduction.
• Greater life expectancy than a non-thermal clutch.
• Briefly engaged at cold start-up.
• Engages at about 170° radiator air temperature, (about 30° lower than coolant temperature).
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 11.4 Sq. In. of working surface.
• Identified by a smooth steel faceplate & thermal spring assembly on the front side.
Heavy-Duty Thermal ….. Corvette AZ GM # 372502
• Turns the fan 80-90% of the shaft speed when engaged for increased cooling.
• 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 26.0 Sq. In. of working area allows higher operating RPM’s.
• Identified by finned aluminum faceplate and thermal spring on the front.
Severe Duty Thermal …..Corvette AX old-GM # 343721 new-GM # 88961768
• 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 70 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.
Here is a link to the full page.
http://www.haydenauto.com/Featured%2...s/Content.aspx
Last edited by ...Roger...; 08-09-2009 at 12:58 AM.