How to tell if a fan clutch is defective
Check for oil streaks (or dust collected on oil streaks) on the fan clutch. It's a sure sign that the internal fluid that provides the clutch action is leaking.
To check for a worn bearing, with the engine off, grasp the fan blade on either end and check for lateral movement. If there's more than 1/4" of side-to-side movement, the bearing is worn and the unit needs replacement.
In checking for proper fan clutch operation, first run the engine until operating temperature is reached. Next, with the engine off, give the fan blade a gentle spin. If it rotates more than twice the clutch is worn and needs replacing. If fan rotation is rough or noisy, or the fan fails to turn, the unit is worn out and needs replacement.
Article from Four Seasons.
2 turns is a bit excessive I think... 1 turn is a general rule of thumb. Or if you feel resistance while turning.
The tough part of checking these things is temperature. If you shut the vehicle off and the fan is engaged it will stop immediatly, if you stop it when the fan is coasting, it will freewheel for a few revolutions and give you the impression its bad.
------------------
Pictures and more...
piston@zkast.com
'71 LWB
350/350T, PS/PB
Special options? Yes, RUST... Need some?
------------------------------------------
Webmaster/Team owner
www.zkast.com
Garrett - Olathe, Kansas
[This message has been edited by Zkast (edited May 20, 2002).]