Fan Clutch Testing

[raunch]

I've got my hands on a heavy-duty fan and clutch that I would like to install. I noticed a little seepage out the backside of the clutch and would like to test it before I buy it. Short of heating up in an oven, any other suggestions?
Thanks.

[DmaxMaverick]

As a general rule, ANY leakage spells a bad clutch. However, if it's been sitting for a couple years in a cool environment, you could luck out once it's placed back into service. Unless it's really cheap or free, I wouldn't touch it. There's really no way to reliably test the clutch off the vehicle, outside of an operating environment.

[raunch]

Good to know. It has been out of the vehicle for awhile. But in order to get it into mine would take more doing than I care for and then find out the clutch is no good. Too bad though, it 's the Eaton clutch and 9 blade fan (I haven't actually counted) off of a 1 ton truck, and I sure could use the extra cooling that would offer. The 1 ton had the serp belt, and the bolt pattern on the flange is different than mine with the v-belts. I could have the flange machined to match my bolt pattern, but I don't want to go to that expense only to find the clutch is shot.
Thanks for the info.

[DmaxMaverick]

You're out of luck, in any case. Clutches are not "backward compatible", and neither is the fan. Serpentine driven water pumps/fans turn opposite of V-belt driven. You'd have to convert yours to serpentine to use the parts.

[raunch]

I noticed the fan blades were opposite of my v-belt set up...thought I could just remove the four bolts that attach the fan to the clutch and turn the fan around. Didn't know the clutch was directional, though. Again, good to know.
Thanks again.

[DmaxMaverick]

Funny thing about those fans.....Install them forward, or backward, they still blow the same direction. The output direction is built into the angle of the blades, and the angle is exactly the same, regardless of the direction it is installed. (sorry...strike 3) And, if by some strange chance (defying laws of science), it did work "backwards", the fan would be operating far outside its efficiency, because the blades are engineered to work in one direction, with the blades effecting the air on that side of them. They are asymmetric. Even boat propellers, computer fans and stand-fans (like you'd have in your house) operate on this principal. If rotated in reverse, they will move air (or whatever media), but will usually be inefficient, noisy(er), and consume more energy for a given output.

Still, I think you are right to pass on the deal, with the idea of getting a good fan clutch. If in the future you want to upgrade to a serpentine belt setup, it may be a good deal just to get your hands on the fan (if the price is right, they are expensive retail). Consider the clutch a gamble, so don't pay any more than it's worth in salvage (not much, if any). If you do a serp. conversion, you'll also have to convert the rest of the belt-driven components (fortunately, all but the water pump/fan rotate in the same direction).

[raunch]

Strike three and I'm out...out of options that is. I don't plan on a serp upgrade (is it really an upgrade? That's another post I suppose), but I do have another motor sitting around that I may save it for.

Interesting info on the fan stuff. Thanks for the help.

[DmaxMaverick]

You're welcome.

In my opinion, a serpentine conversion is an upgrade. V-belts are a centuries old technology. Even under the best of conditions, the belts wear relatively fast, slip, loosen, and place a lot of stress on the bearings/mounts of the components to keep them tight. The serpentine setup is self-tensioning and calibrated, retain constant tension, and will accommodate variances within the system (like a pulley slightly out of round, but not bad enough to replace). They last a very long time, compared to V-belts. Not to mention the ease of installation and maintenance, and a more simple diagnostic process when something does go wrong. Belt driven accessories also last longer because of lower levels of overall stress.

A worthwhile upgrade, if you happen to be in the neighborhood (already facing replacement of one or more failing components). Complete conversion kits can be had for a price, but it can be done relatively inexpensive if you scrounge up the parts over time.

[Yukon6.2]

I remember reading about tweeking the bi-metal spring to make the clutch engage sooner.Does anyone remember how to do this?
Thanks Thomas

[DmaxMaverick]

I remember reading about tweeking the bi-metal spring to make the clutch engage sooner.Does anyone remember how to do this?
Thanks Thomas

.....by tweaking the bi-metal spring to force it to engage sooner.

I've done this a couple times, and found it didn't really help. It actually caused the clutch to be very inconsistent. The adjustment is VERY sensitive. If you want a lower ECT, and sooner fan engagement, change your thermostat(s). Works every time.