So my 72 H/O was warming up at some traffic lights this summer. I did not care for how loosely the fan would spin on the axle. So I ordered a heavy duty Hayden 2747. This is the standard height one, not the shorty. The fan sits in the shroud but at the edge, so I figure that is aerodynamically enough.

I cuss my way through an install, fire it up, and, with the normal few seconds of shake on a new clutch, all is well. I go for a drive, hit 50, and have the worst buzz vibration fill the cab. It's like the minutest of washboard. I can outrun it, so I get on the interstate and find my race gas / 91 blend is good for my timing at the moment, which I will fix with a comprehensive tuneup later.

I wonder if a tire has **** the bed. I had them lug centric balanced because I am apparently ignorant, and SSII bolt ons are hub centric. Maybe I should rebalance.

Heading home, I keep it in second. At the same RPM, the buzzing vibration occurs (this would normally be in top gear at this speed.). I take a side road, put it in first, and get the same buzzing in first at the same RPM.

I get home, rev the engine in park to that rpm, get the buzzing.

My tach is off, but I believe the rpm range is 2000-2500. This did not happen before the clutch replacement. This is an odd failure mode for me for it. I expect poor cooling performance, or complete shake from idle on up. The fact that it happens in all gears leaves out everything from behind the transmission backward. I suppose torque converter bolts may be loose? Odd timing. I could not see a way to clock the new clutch, it looked axially the same. I torqued to spec. There was a bushing I did not use as the previous one had none, and there was not much for it to sit on anyway. Mine has short studs, nuts, and copper crush washers.

I will try another, non-HD clutch, as I don't think I need the HD, the 4 core holds onto the 455 well. This car is grounded for this weekend's adventure.

Thank you for advice.

 

I think it may be as obvious as it seems. The part is faulty, not entirely, just enough to be shoddy at a specific point.

The fact that it happens at a specific rpm and not a specific speed should rule this out. Because as you know different gears do not hit the same mph at the same specific rpm. But I will throw this in for good measure.

Apples and cantaloupes but a 2014 Honda CRV had a similar complaint. At around 35 mph it had a vibration. Google indicates that that's anywhere from 1500-2500 rpm... (didn't verify) And this was the solution...

"I just sent my car for balancing and rotate yesterday. After that, the steering no longer vibrates now. The balancing surely helped. But my feet could still feel the shudder at the 30-40 mph."

"Here is the latest update on the car vibration issue. Based on many of the recommendations that was posted here, I finally had the car transmission fluid drained and replaced. Just exactly as how you guys have suggested, that completely solved the problem. The car no longer vibrate at low speed anymore.
Thank you to everyone."

power.rst8_183478 of https://community.cartalk.com/t/car-...fter/188139/12

 

Yes, I think you are right. Plus, I don't like the awesomeness of the HD clutch. I did notice the car was running cooler at low speeds, like I would estimate 10 deg on the gauge, but that's down into probably 170. Doesn't need to be that cold.

I will fire up the engine cold, and see if it does it, then I am removing belts and doing a quick beltless run to see if it is gone. Or I may just swap the unit proactively. Rock Auto order.

 

215046 carquest is the part I use on my '72 350 - has been a solid performer right out of the box for several thousand miles now. It's installed on a '76 Corvette 7-blade fan and my engine temps range 180 - 190 on average in mixed FL driving heat.

Might be a thought for an alternative to the Hayden.

 

I would start here. Put the bushing on the water pump, then put on the fan clutch, and tighten it down. There should be enough length on the water pump shaft for the bushing to center the clutch as you tighten it.

 

There wasn't one previously, and there is a little bit of water pump snoot. I don't think being 0.05 in off center will cause this. I will put one on with the next clutch.

 

I wonder if your fan is out of balance or bent? My Cutlass got hot after idling a while, so I bought a cheap fan clutch on Amazon and installed. Man did it ROAR!! I thought it was because it was a cheap unit and I bought a Hayden, it also roared. My point? I drove the Olds around for years and never heard a roar- because my original clutch fan was slipping. Then after putting on both new clutches- they roared. What if your car has a out of balance or bent fan blade or something, but cuz your original clutch was slipping, it never got up to RPM needed to make you notice it?? Now w/new clutch it gets up to the RPM ??

 

If it is truly .050" it will absolutely cause a problem. That is close to 1/16" off center.

 

X2
If the clutch you took off was the original, it should have a smaller hole and not need a bushing. Does the bushing fit in the hole in the old clutch? The bushing comes with the new fan clutch because they are made to fit multiple vehicles, some of which have a larger water pump shaft. The bushing only needs to center the clutch while you tighten it down. Once it is tight, the bolts/ nuts will keep it centered. Just for fun I went out and measured the shaft on a 455 water pump and the hole diameter of a replacement clutch. The water pump shaft diameter is .625" and the new clutch hole diameter is .750". It is unlikely you got the clutch completely centered without the bushing.

 

I will replace clutch with lighter duty one, and check snoot to socket clearance and shim thickness stackup. I will confirm fan is flat, but it looks it now.