Oldssupreme

Hi! I'm almost to the point of starting her up. Just curious as to whether or not the fan should spin freely by hand? I can spin the fan fine, but it does not continue spinning after I let my hand go. There is a new thermal clutch on it, new water pump, new belts, new hoses etc As I mentioned, I have not started it up yet since I installed all this. Does this sound like an issue?

don71

That sounds normal to me. There is a viscous fluid in the center piece that is part of the thermal clutch operation.

Oldssupreme

Thank you Don.

CRUZN 66

Shouldn't be an issue... Sounds like the new clutch you installed is doing what it is designed to do...

Oldssupreme

Ok, thanks! Last time I change the clutch was 1996 so I don't quite remember. Thank you both.

Allan R

Was the car up on jack stands when you installed the shroud? If it was you might want to check for clearance on the fan when it's sitting on the ground. That may have changed slightly. Don't ask how I found this out....

Oldssupreme

Allan it's funny you say that because as matter of fact yes it was up on jackstands and I AM having issues with the fan contacting the bottom of the shroud and I was too embarrassed to ask about it. If I get underneath and push the bottom of the shroud toward the front of the car it clears the fan blades but I don't see a way to adjust it to "stay" in that position. What are you thoughts and your experience? Thanks Allan!
Chris

Fun71

On my car I put some spacers between the upper shroud mounting bolts and the radiator top plate.

Oldssupreme

Fun71, so that forced the shroud down to help the blades clear the bottom of the shroud?

Allan R

Chris, what Kenneth said. The Assembly Manual states to "shim as needed" to get the necessary clearance. In my case it's 3 shims on each side of the shroud top. You might also want to see if you can bend the mounting tabs on the bottom of the shroud a bit? It might not be easy to get those bolts that hold the shroud in place though.

The reason the shroud is hitting: When the car is up on jack stands there's nothing supporting the weight of the engine and the front frame horns will droop slightly under the load. If you support the engine cross member that will usually take the problem away. Or you can just work it from on the ground.

Oldssupreme

Allan and ken, it seems like when I shim it at the top I'm not sure it's actually pushing the bottom down and toward the front as it needs to go to clear the fan. Maybe it's bowing in the middle. Who knows. Maybe my core support is bowing up under the shroud slightly causing the shroud to be higher than it should.

Allan R

That's why I asked if you could bend the mounting tabs at the bottom of the core support. The core support shouldn't be bowed. You might have to shim the lower part where the shroud attaches to the mounting tabs too in order to move the shroud back a bit.

Oldssupreme

So Allan are you suggesting I bend the core support mounting locations back? the first message asked if I could bend the mounting locations on the plastic shroud but your second message I think is suggesting to bend the metal core support mounting areas. Can you confirm this? I think that might work although I'm not at home so I can't exactly picture whether that's possible. Thank you!

Allan R

You won't be able to bend them much. If you had a fan shroud before you did your restoration it should bolt back in without much hassle. I'd try mounting the shroud first with the car at ride height on the ground. If that doesn't work, you can also shim the lower part of the shroud to force it further forward. I think (and I could be wrong) that your fan is hitting on the inside of the shroud? Try the shims from the top first to see if that will work. The bottom shroud mounting tabs are welded in place so they're not going to move, just the angle of the tabs will.

Allan R

Chris, one more thing comes to mind. Did you by chance change your water pump? If you did and it's a longer snout that may be your problem. There are 3 different lengths. If yours is now longer, that would account for putting the fan in a position where it might be scraping the inside of the shroud. Ways to fix: get water pump with shorter snout, or get a new water pump pulley with a deeper bell to offset the longer snout. If that doesn't make sense, PM me and I'll go through it with you.

Koda

As far as I can tell, a clutch fan can do four things. One, spin freely. Two, be totally locked up. Three, spin about one half a revolution. Four, spin about a blade's width, like 45 degrees.

One and two means it's toast. Three means it's disengaged and cold. Four means it's hot and engaged.

Oldssupreme

Thank you Allan. I will be looking at it this weekend so I will most likely PM you. And thank you Koda for your post. Much appreciated

Oldssupreme

Allan, I did get a new water pump which I thought was the same size, but perhaps not. Do you know what the original distance between the radiator and the thermal clutch should be? If so, I can measure that And determine if that is my issue, or the shims are my issue. Thanks guys! Chris

Allan R

Chris, have a look at this thread. John has excellent pictures, Joe chimed in on post 7 with length measures
Water Pump Lengths

Allan R

Chris, here's something for you to reference
71-72 Olds A body

350 with A.C.or H.D. Cooling 5.95" Casting 231073 <<< I believe this is your application. Aftermarket castings may have different numbers but this gives you the length

350 w/Air Pump 5.57 Casting 231066

350 w/o A.C., H.D. Cooling, O.A.I. or Perf. Axle 5.09" casting 231065