My 93 AED was running a bit hot, w/ 138K I had the radiator rodded-out and previously had replaced thermostat. It runs cooler during most operation but when towing and a/c on gets pretty warm (up to the L on the gauge). I am suspecting the fan clutch but not sure how to test these. If the motor gets warm, don't they lock up and stay locked up even with the engine off until it cools down? Mine never seems to engage and I can't hear the thing kick on (am I supposed to?).

Appreciate any advice as to this issue or anything else it could be.

Mark

 

This may not be much help but I ran into the same problem of not being able to determine if the clutch was working or not. The engine temp started to creep upwards, especially during stop and go driving. I finally bought a new one and after getting the old one off, I still wasn't convinced the old one was bad. The old old actually had greater resistance to turning than the new one (at room temp). I put the new one on and problem solved. (As an aside, some fan nuts are right hand thread, others left. Correct removal direction is stamped on the radiator fan shroud for the 4.0 engine)

 

Thanks Aero, I can almost always count on words of wisdom from you. If anyone knows for sure how to test these things, I'll take any advice.

Thanks
Mark

 

Well, according to the factory service manual, here's how you test it. With the engine off, rotate the fan by hand. The pass/fail criteria is smooth rotation with slight resistance. The only problem is defining "slight".

Like aerocolorado, I too have noticed the temperature on my Ranger (the Aerostar is not doing this yet) creep up. I "tested" the fan and I would say it passes but I have my doubts. Since the fan blades are cracked, I will probably just put an electric fan in so I won't have to worry about fan clutches any longer.

 

[updated:LAST EDITED ON 30-Aug-02 AT 10:24 AM (EST)]The fan clutches do wear out over time.
Test methods include:
1) watch the fan as you turn off the engine from idle. The fan should stop turning almost immediately. If it spins on... replace it
2) if it is leaking the silicone fluid.. replace it
3) if you can move the fan forward and backward(front to rear on the fan axis).. replace it
4) if you can spin the fan by hand, and it turns more than 1/4 of a turn.. guess what? replace it.
5) you *should* be able to hear the fan 'lock-up' by running the engine at idle for a while... it should suddenly start to blow a significantly increased amount of air... if not...

I have heard that the non-factory (pep-boys/autozone/kragen/etc) are not as good as the OEM. Just an observation. Experience too. Bought a brand new fan clutch at Advance Auto Parts. Had oil on the packing material, but was told 'thats the only one we have in stock'... Installed, worked just about the same as the one that I took out.. except that it spun easier. Took it back...

tom

 

>I have heard that the non-factory
>(pep-boys/autozone/kragen/etc) are not as good as the OEM.
>Just an observation. Experience too. Bought a brand new
>fan clutch at Advance Auto Parts. Had oil on the packing
>material, but was told 'thats the only one we have in
>stock'... Installed, worked just about the same as the one
>that I took out.. except that it spun easier. Took it
>back...
>
Tomw, this closely mirrors what I was referring to earlier. The new fan clutch actually turned easier by hand than the old one. There was a note in the box stating that since the clutch sits on its 'nose' while shelved, the viscous fluid may need time to settle into the proper position after installation. I went ahead and installed it and it did solve the overheating problem, indicating the old clutch was indeed bad. So, I can only infer that unless the fluid is actually leaking out of the clutch, all other testing methods are suspect.