Belt Squeal at higher RPM after clutch fan install

Gents,

I recently replaced the stock fan with a FlexALite standard duty thermal clutch and 18" fan assembly. As the specs on the clutch say not to exceed 4,000 rpm, I figured that under normal driving conditions and a typical shift point of 3000 rpm, we should be fine. Well, each time we approach 3000, the belt starts to sing, and as we get towards 3500 its howling. What's the fun of having a Clev-O if ya can't rev 'er up?

Anyone have any thoughts before I chuck this thing back in the box and return to Summit?

Thanks

Butch

Return it, I picked up a clutch fan off of an 80's lincoln that works great and it has handled rpms in excess of 4000 quite regularly. I go it at pull a part for 10 bucks lol.

I went to an electric fan years ago-I've never regretted it, plus when it is time to work on anything in the engine compartment it tends to allow easier access.

I would be sending that one back right away.

seriously 4000 isn't much if you have low gearing.

on the highway at 70mph i'm doing 3000 with a 3.00:1 rear.

with a 3.5:1 ratio in the back at 70 you would be just a touch under 4000rpms. if you had a 4speed or AOD then it would drop to 2,500 rpms at that speed.

the 4000rpms is just too close to the modern highway speeds we all need to go at today.

With the 5 speed and the 3:50 rear, it runs around 1800 at 60 and 2200 at 70. Its climbing through the gears when things get noisy under the hood. I think I'm gonna swap the old fan back in and see if the squeal goes away.




Thanks, Jeff- I was looking at electrical, but was talked out of it as this was supposed to be a simple swap. I think I'll try Mikes approach and hit the Pick a Part. Maybe while I'm there I'll see if they have a Crown Vic electric fan, too - just in case!!

:thankyouyellow:

Sure enough, back to the old fan and no belt squeal. Any ideas as to why the noise with the clutch system?

well if you google fan clutch it goes hand and hand with belt squealing.

some people tightened the belt as much as possible and say it stopped.

some say its the inertia of the fan kicking in that causes it.

some say if the belt is too tight it squeals.

another one said roughen up the pulley with sand paper so the belt has more traction.

If it's the fan you want, try installing an underdrive crank pulley. I had an issue throwing belts after installing taller gears. That big stock crank pulley can be an issue st high rpms, or in this case a higher drag fan.

I believe the '80s Lincoln fan, and some other cars, have both thermal and speed sensing, so the fan also disengages above 3,000 RPM. Most truck fan clutches just have the thermal coupling.

interesting thing i didn't know was the fan clutch degrades over time, it loses about 200rpms a year with it's settings so after a couple of years you need to replace it to maintain the same performance.

All,

While investigating further, I went back to the Flex-A-Lite website and found that the clutch I ordered was a reverse rotation unit. I contacted their tech line to confirm this, and yep! I ordered the wrong clutch for the car. lollerz

Here's an interesting point I found following up on Mike's suggestion of pulling a clutch off of an '80s Lincoln- if you look up fan clutches on Rock Auto for that make/model/generation, it shows that they are offered in both clockwise and counterclockwise rotations- so ya gotta know what you're looking for when ya play in the yard!

Thanks for all the help and input!!

::thumb::

cool glad you figured it out and we all learned something too.

Glad we could help.