Hey Guys... I have a 71 with a 350/350 originally had AC but it's been removed. I pulled the motor a few months ago and just recently got it back in and on the road. While it was out, and the fan was removed from the motor I noticed some oil leakage from the clutch. I took the car out for a little longer drive the other day and noticed a nasty squel noise under the hood after about 15-20 mins of driving. It did it again yesterday, again after 15-20 mins of driving. I'm getting suspicious that it's that fan clutch? Does this sound right to you? Would a bad fan clutch typically make a nasty squel like that when it locks up?

Also, if I do replace it should I go with centrifigal or thermostatic? Pretty much a stock 350 that I use as a weekend cruiser.

Thanks

Pat

Couple years ago a guy at work asked me same question about his S-10, except he doesn't know a fan clutch from a clutch of eggs. Water pump was shot. Lucky he didn't damage the radiator. New Carquest pump and belts and he was good to go again.

I'd stick with thermostatic. I've never heard one squeal, but if a lot of the oil has leaked out I suppose it could. Do the engine temps stay within an acceptable range in all driving conditions? It's not unusual for a fan clutch to have a LITTLE bit of oil on the outside and still work fine. When it starts flinging clutch oil on the fan blades and the inside of the shroud the seal is gone. Another easy test is with the engine all warmed up and the engine OFF, spin the fan in the proper directions with you fingers. If there is little to no resistance the clucth is going bad.

A good point is made above, a squealing sound could be the sound of the belt slipping due to a water pump which is about to seize up.

Thanks guys... I'm still on idiot lights so can't tell actual temps at this point but don't see any signs of overheating. The thermostat does appear to opening fine. I probably wiped up about 4 or 5 quarter size puddles of oil beneath the shelf that the fan was sitting on and it does look like there's some residual oil on the newly painted fan blades. Is the fact that the noise doesn't happen until 15-20 mins of driving consistent with a potentially failing water pump?

Also, the current clutch doesn't have the spring on the front so I assume it's a centrifigal model. Sounds like you believe switching to a thermostatic is a better choice for my application?

Thanks

Pat

Well, don't go replacing parts that don't need to be replaced. Where exactly is the squealing coming from? Once it's warmed up can you open the hood with it running and locate the source of the sound? Is the belt old? Is it properly tightned?

Thanks Rich.. That's my plan for tonight (when I get done with the job that helps me pay for this hobby). This weekend was the first time I got it out and running in excess of 20 mins since I put the motor back in and thats when it started. I knew that clutch had leaked oil so I was curious if you all felt that just the leaking oil was enough to say it was toast and I should pick one up regardless of whether it's the cause of the noise (In which case I could grab one from NAPA on the way home). Sounds like it's best just to fire it up in the garage and let it run for a while and see if I can get it to duplicate the squel noise to try to further narrow it down. The noise is not constant from what I've experienced so far but I have not run the car for more than 5 mins after it happens. It's like something starting up/engaging and just making noise when it starts but then is fine. All of the belts, hoses and radiator core are new. I'll double check the tension on the belts before I fire it up tonight.

Thanks

Pat

So tonight I ran it in the garage (couldn't get it on the road.. 3 kids.. wife had bunco night). I let it run for 45 mins. After about 20 or 25 mins it developed a muffled clunky rattle in the fan/pump area that was constant (not the short sudden loud clanky like it's been doing when driving). At no time during that 45 mins did it seem like the fan noticeably locked up. I should have shut if off and tried to turn it right away, simply forgot to do that. I'll give that a go tomorrow. Any thoughts at this point?

Thanks

Pat

Wanted to post an update. Turns out the fan clutch was the issue. It took me a while to get it fixed bacause apparently the 71's with AC had a unique fan clutch bolt pattern (rectangular) so the search for a replacemants wasn't easy. Actually I gave up and bought a new fan (with square bolt pattern) for now.

Appreciate the assistance guys.