Modify Fan Clutch

[Sedition]

Recently my belt driven fan has been letting me down on the beach. I have found some information on the internet talking about tightening the bi-metal spring to make it kick in earlier. I'm going to attempt to do this after my engine is cool enough to work on without burning myself.

During a cold start in the morning the fan will engage then disengage soon after, sometimes it cuts in and out repeatedly during a cold start. As my engine and transmission heat up the fan clutch will not engage fully like it used to. This is never a problem on the road but can be deadly on the sand.

I just want to do a quick fix for now untill I can get my hands on a set of electric fans that can take a beating.

I already had the fan off last night and polished it up like new, including the Bi-metal spring. It seems to pull a little more air now but nothing like it used to.

Has anyone else on here tried to remedy thier fan by tightening the coil of the bi metal spring? By "tightening up" I mean loading more tension into the coil spring.

 

[Sedition]

OK, so it appears the bi-metal spring turns a pin in the center of the coil from right to left as it heats up. I can't get my spring to move the center pin just by using a cigarette lighter, so I guess I'll remove the outer part of the spring from its mount then reattach the fan to my engine and see if I can get it to kick in manually.

As I move the center pin from far right the left, the nut doesn't appear to become any harder to turn by hand but I guess it's a different story when attached to the engine.

 

[Sedition]

Clutch not busted!

Well, turning the center pin all the way to the left has pretty much locked the fan to operate 1:1 with the water pump pulley. With it at this setting I'm too scared to rev it over 4000rpm, the fan is screaming. Fortunately I can just reach in there and turn it up or down at any time as I have left the cowling off. I'll have to be careful not to burn the hell out of my hand while reaching in there...:fire:

I might set it some where down low, towards the right, for on road operation and when I pull over to air down my tires for beach running I'll have to reach in there and crank it up to the left. Now if only I can do this remotely, while driving along.

This is a pic of the spring before I popped it out. It looks very clean but still did not want to operate.

 

[Runnin'OnEmpty]

Hi Sedition; I tinkered with the fan clutch on my
(cough)Jeep last Fall. I didn't
have any luck so I just bought a new aftermarket
clutch. After driving it during a hot spell this Spring,
the results are amazing. The Jeep runs much cooler
and at a constant temperature during all driving
conditions.

What this tells me is that these fan clutches DO
wear out. The old one didn't have any signs of
leaking or damage, and it still worked somewhat.
But the new one worked much better. IIRC, it
was a Hayden brand...