340 FAN CLUTCH QUESTION

[CFD244]

Hi Folks

I've got a couple of fan clutches with the bi-metal spring mounted on the front. Is there a way to check them to see if they are any good without mounting and running them on an engine? Thanks.

 

[Dana67Dart]

You should be able to freewheel them when cold. Get a hair dryer and heat up the front area, not too much heat!
(You could also boil a 6 quart pot of water on the stove and support the clutch above the boiling water.)

And you should start to feel drag.

Not a guarantee that with the load of a fan it will work correctly but might be Isn indicator

 

[AJ/FormS]

Some of those are designed to fail in the closed position , so that, first start every morning, you will hear the fan roaring for a bit, before it settles down.
I have one like that, and I like it cuz when I hear it, I know we are good to go.

 

[RustyRatRod]

Sometimes, you can also tighten the spring up one round and they will tighten up if they are loose. Most of the time though, that looks them up too much.

 

[CFD244]

If I check them both on the shelf in the same ambient temperature, one is harder than the other one to turn by hand. Not sure if one is better than the other?

 

[oldkimmer]

340s had a declutching fan, not a thermostatic fan. If it has a spring it is not a 340 fan. The harder the better. Kim

 

[CFD244]

I thought the AC 340's had the spring? You learn something new every day.

 

[oldkimmer]

I thought the AC 340's had the spring? You learn something new every day.

Not that I’ve seen here in Canada. But I’ve only seen a hand full up here. Kim

 

[AJ/FormS]

Likewise; All classic 340 cars that I have paid attention to were of the viscous coupling kind............ but to be fair, NONE of them had A/C so IDK.

 

[Dicer]

1970 Service manual

 

[RealWing]

NOS 1969 340 AC clutch

 

[oldkimmer]

Well I learned something today from u guys. Thanks. Kim