Stock, our fans had a clutch on them, right?

[TIMSPEED]

Reading the Haynes Manual, and talking with people, it/they've said my truck needs a fan clutch. My fan runs continously off the belt. I put a thermometer in my radiator today, and it said 100º. So, I think I need to get a clutch in there, so it won't run so cold. Cold is good, just not THIS cold.

[ocbaud]

my old stock fan had what looked like a clutch plate, but it always ran

[C-10volvo]

i dont think just a fan would cool an engine by that much. but yes, they did come with clutch fans. i would first check your stat to make sure its not stuck open and not allowing the motor to reach a normal operating tempature.

[ocbaud]

how would that fan clutch work? my fan was just hooked up with belts

[C-10volvo]

Originally Posted by ocbaud

how would that fan clutch work? my fan was just hooked up with belts

the clutch is bolted to the pully, and the fan is bolted to the clutch. the fan will always be turning, but not as much because the clutch will always be slipping depending on the rpm.

[76sierraclassic]

I just recently had to replace my fan clutch because it wouldn't disengage. The faster I ran, the faster the fan turned, and all I got when I would get on it was a loud whirrrr from under the hood, and occasionally if I was really getting on it from about 30 mph, it would squeal the belt. All of my horsepower was going to the fan instead of the rear wheels.

When I went to O'Reilly's to get a new one, they had a couple of different ones listed but told me that mine originally came equipped with the "heavy-duty" one. I think the difference is that some are thermal and some are not. The heavy-duty one that I bought is thermal, meaning that it will engage/disengage not only based on RPM but also by temp.

Hope this helps...

Mike

[Grim Reaper]

If it had A/C it got a clutched fan. Non A/C was direct drive I think.
A clutch is never a bad deal because when it's running cool enough the clutch will disengage and lower the darag on the motor.

The thermostate contols the engine temp. if the engine is running too cool put a different thermostat in with a higher temp.

Yeah I know it's

[BillyJack]

Well, 76sierraclassic, that's exactly what mine did the other day and it "freaked me out"... I don't know if you were in on that thread. (engine / drivetrain group). I was given a non-thermal clutch when i went to pick up the part yesterday. I think I want a thermal clutch though, cause it'll disengage when it's cool too, thus saving more power / gas for the wheels... (i guess). I will probably take it back today and get the thermal.

Not to threadjack, but my engine temp wire is pretty much deteriorated all the way back to the wire-loom at the firewall. can i run a new wire from the gauge (haven't taken that stuff off yet so it might be a chore) to the sender or is it much more work than that?

BillyJack

[76bonanza]

The fan clutch is either thermal or by rpm.

The thermal will disengage by temp and the none thermal will disengage by rpm.

I am pretty sure all our trucks used a clutch of some kind.

[cliffsta]

Yeah my truck runs real cool My dad told me the original radiator blew a while back, and the only radiator the guy had in stock was like a 350 or HD or 350 HD, and my truck has a 305. So of course my dad made it fit. The temp gauge never makes it past the 1/4 mark

[plumbcut]

Grim is correct, every non-ac truck Ive seen have had no clutch. AC=clutch

pc

[C-10volvo]

Originally Posted by plumbcut

Grim is correct, every non-ac truck Ive seen have had no clutch. AC=clutch

pc

my truck doesnt have a/c, but has a clutch. the truck has been in the family since it was new and the engine has not been messed with.

[plumbcut]

well in the '70's this was definately true. The only other possible explanation was that manual trans trucks had non-clutch fans..

ive seen many non-ac trucks with solid mounted fans, but they all also happened to be manual transmission trucks. coincidence? maybe.

every clutch-having truck that Ive seen have had an automatic and AC... coincidence? maybe. And Ive seen and owned a lot of very very original trucks.

Did the ruleset change during the 18-year run of this bodystyle? undoubtedly.

Tims truck is a '75 and i believe grim's and mine assessment to be true

pc

[Grim Reaper]

Originally Posted by cliffsta

Yeah my truck runs real cool My dad told me the original radiator blew a while back, and the only radiator the guy had in stock was like a 350 or HD or 350 HD, and my truck has a 305. So of course my dad made it fit. The temp gauge never makes it past the 1/4 mark

Anint no making it fit. It's "GENERAL MOTORS". Its all bolt in.
Seroius. The Deisel trucks had the bigest radiator. It's wider then the whole in the core suport so the main suport on either side of opening. THe one on the driveside is swiss cheese to alow air flow for the wider radiator. It will bolt into your trick with the correct retaining bracket.
You want a K5 with 1 ton axles? You gt a D60 out of a K30 and bolt it in. Get a SRW 14 bolt and bolt it in. You don't have to make GM parts fit a GM truck.

[Grim Reaper]

Ohh it doesn have to even be the same body style. either on some stuff. The complete front 2wd sub assembly from a 87 will bolt into a 63 with only two holes needing to be drilled. All these folks buying these expensive kits to convert 70 and older trucks to disc front do it the hard way if they don't care about rims. They just need to hit a junk yard and get the front fram from fire wall out. That gets them the disc CV all the hard lines and a sway bar and it will all bolt onto their older frame.

[cliffsta]

no no no, all i ment in "making it fit" was that he had to cut that bracket or something. darn you guys need to quit jumping down my throat. sorry that im only 16 and im just going on what my dad said years ago on things he did years ago.