Fan and clutch problems

[berfinroy]

I am getting what I think is excess fan noise from my 72 4.5, most pronounced around 60 mph. Clutch is relatively new. I don't know how much clutch resistance is the "right" amount when engine is at full tempreture. Mine's pretty stiff and appears to run awfully fast when I rev it up at a standstill. Do I have a clutch problem?
Has anyone simply done away with this system and replaced it with an electric thermostatically activated fan?

[Takernz_30]

Originally Posted by berfinroy

I am getting what I think is excess fan noise from my 72 4.5, most pronounced around 60 mph. Clutch is relatively new. I don't know how much clutch resistance is the "right" amount when engine is at full tempreture. Mine's pretty stiff and appears to run awfully fast when I rev it up at a standstill. Do I have a clutch problem?
Has anyone simply done away with this system and replaced it with an electric thermostatically activated fan?

these fans runs on visco-clutch it works similar to the ones on LSDs(limited slip differentials), at idle, the fan spins slower than the crankshaft, as you rev, the liquid inside the visco-clutch fan heats up quickly and expands and locks the clutches inside to match the crankshaft speed, back in idle, the liquid cools and contracts and disengage the clutch and the fan is spinning slower again, that how the visco-clutch fan works.

check it with engine off, rotate the fan with your hand if it spins freely,that's ok. if it's stiff, replace the visco-clutch fan if you want it that way. If you want the electric fan set-up, 16-inch fan is ok install a fan relay and thermo-switch at the thermostat housing cover, 80-100C depending on your location(if hot climate use 80C thermo switch, if cold use 100C).

Connect those 3 components (relay,switch and fan) in series with the source, that's it.

[berfinroy]

Does anyone know of a 16" electric fan set up that will work? It looks to me like I will have no more than 3" clearance from the radiator to the pulley nose after removing the stock fan. I haven't seen an electric fan with less than 3 1/2" depth.

[sjefke]

Are you sure it is the fan that is making the noise? If you hear a fan over 60 mph wind noise, it may be a bearing or interference issue.

Bert

[bwostosh]

or motor mounts, or subframe mounts or flexcoupling, or center support bearings, or muffler to body , or, or on and on.... even the tires.... so many things are possible which effect the noises you hear (besides wind).

Believe this or not.
I sand the fan blades smooth because I can get these cars so perfect that ugly fans are heard. (over 70-100mph)

[Mike D]

Try this link

Fan Clutch question