Fan Clutch

[Frank K.]

How do you adjust the coil type fan clutch? 77 car I can not see the diagram in the NCRS book Will the adjustment drop the temperature in my engine at high speeds?Is there fluid in this unit?

[Joe L.]

Re: Fan Clutch

How do you adjust the coil type fan clutch? 77 car I can not see the diagram in the NCRS book Will the adjustment drop the temperature in my engine at high speeds?Is there fluid in this unit?

Frank------


Which fan clutch do you have? A photo will help us identify it.

Generally, fan clutches do not provide much of the cooling when the car is traveling along at speed. The main purpose of fan clutches is to provide airflow when the car is at low speed or idling.

Yes, if it's a thermal type clutch (which all OEM clutches are), there is silicone fluid in it.

[Frank K.]

Re: Fan Clutch

I have a thermostatic coil according to picture of cooling system in NCRS book.

[Jack M.]

Re: Fan Clutch

I'm not sure if this old article will help: CLICK HERE

[Joe L.]

Re: Fan Clutch

I have a thermostatic coil according to picture of cooling system in NCRS book.

Frank------


ALL 1977 Corvettes used a fan clutch with a coil type thermostat. However, there were at least 2 different clutches used. In addition, how do you know that the clutch on the car now is original and not an aftermarket replacement?

[Frank K.]

Re: Fan Clutch

The fan clutch is original to the optional L-82 mtr with 4 speed trany.

[Joe L.]

Re: Fan Clutch

The fan clutch is original to the optional L-82 mtr with 4 speed trany.

Frank-------


Does the car have C-60 or VO1 HD cooling. If so, you should have a GM #343721 fan clutch which is an excellent fan clutch and the predecessor to the GM #88961768 which I recommend.

Does it look like this (except with just a 4 hole hub, not the 8 hole pictured):

[Frank K.]

Re: Fan Clutch

Yes mounting 4 hole

[Leif A.]

Re: Fan Clutch

Frank,
Depending on the age of the clutch, re-positioning the end of the coil spring 1/2-turn counter-clockwise (as viewed from the front) may cause it to engage about 15*F sooner.

[Frank K.]

Re: Fan Clutch

Fan cut out type Thermo-modulated viscous-clutch

[Joe L.]

Re: Fan Clutch

Frank,
Depending on the age of the clutch, re-positioning the end of the coil spring 1/2-turn counter-clockwise (as viewed from the front) may cause it to engage about 15*F sooner.

Leif------


I don't think that can be done with this configuration fan clutch.

[Joe L.]

Re: Fan Clutch

Yes mounting 4 hole

Frank------


Yes, but does your clutch otherwise appear exactly like the one I pictured?

Also, keep in mind that if yours is original to the car, it could be worn out. These things are not "forever" pieces.

[Frank K.]

Re: Fan Clutch

Exactly also C60