68 Hydraulic Clutch Fan failure....

[Peter M.]

I have a '68 Corvette 327/300 HP engine with the short water pump which I understand limits the options for clutch fans for some reason. I have had several of the stock Corvette hydraulic clutch fans go bad on me by leaking fluid or simply being out of balance.

My question is how have others solved this problem? What other options might be available to solve this continuing problem? What is the part number for the OEM short water pump hydraulic clutch fan? Where can I get a properly balanced OEM style replacement?

Any help will be greatly appreciated.

[John H.]

Re: 68 Hydraulic Clutch Fan failure....

Peter -

The currently-available replacement is GM #3916141, made by Eaton, and they're brand-new; Paragon has them, so does GMPartsDirect.com, for about $125.00.

[Peter M.]

Re: 68 Hydraulic Clutch Fan failure....

Peter -

The currently-available replacement is GM #3916141, made by Eaton, and they're brand-new; Paragon has them, so does GMPartsDirect.com, for about $125.00.

Can you recommend a good shop to properly balance the OEM fan assembly?

[Jack H.]

Re: 68 Hydraulic Clutch Fan failure....

I don't know of anyone providing radiator fan balancing services...

I suspect the factory original balancing technique on early fans was to 'shave' material from the outer edge(s) of individual fan blades. I say this because later fans sport visible balancing weights on individual blades and the early fans don't.

So, for grins, I once rounded up six early fans and carefully measured the length of each blade. I found a variance of 90 mils in length that I suspect is WAY outside the native tolerance of the stamping/forming dies that originally made the blades...

But, if your fan is otherwise 'untouched' (no blades replaced), I suspect imbalance is due to either the center spider being bent AND/OR individual blades being bent. If that's the case you should be able to see fore/aft wobble looking at the edges of the fan blades as the fan assy rotates.

If that's the case, you should be able to true the fan yourself. Consider setting it on a flat/true surface and see which blade tips aren't touching down. Bend the offending blades fore/aft until you have achieved uniform concentricity...

[Joe L.]

Re: 68 Hydraulic Clutch Fan failure....

Peter -

The currently-available replacement is GM #3916141, made by Eaton, and they're brand-new; Paragon has them, so does GMPartsDirect.com, for about $125.00.

John and Peter-----


Also, check with "the partsladi" (found on eBay). I think they can sell you the the exact same Eaton unit for about 70 bucks IF you will accept it in a "generic" box. If you want it in a GM box, it's about $125-150.

[John H.]

Re: 68 Hydraulic Clutch Fan failure....

John and Peter-----


Also, check with "the partsladi" (found on eBay). I think they can sell you the the exact same Eaton unit for about 70 bucks IF you will accept it in a "generic" box. If you want it in a GM box, it's about $125-150.

Joe -

I've seen some bad reports recently on that $70.00 clutch from "Partsladi" that's in the generic box, that were cured by using the genuine Eaton clutch in the GM box. Haven't had the parts in my hand to compare them, but the finish is completely different on the generic clutch.

[Joe L.]

Re: 68 Hydraulic Clutch Fan failure....

Joe -

I've seen some bad reports recently on that $70.00 clutch from "Partsladi" that's in the generic box, that were cured by using the genuine Eaton clutch in the GM box. Haven't had the parts in my hand to compare them, but the finish is completely different on the generic clutch.

John-----

That's interesting. I was told "by a reputable source" that both were Eaton-manufactured pieces and the difference was that the "generic" clutch was sourced direct from Eaton rather than through GMSPO. If so, though, I would think that both the GM and "generic" unit should be identical in both finish and functionality. I'd like to see one of these "generic" units.

[Michael W.]

Re: 68 Hydraulic Clutch Fan failure....

The OP's similar post on that 'other' web site mentions having a severe vibration that goes away when the fan belt is removed. Methinks that there's some related component causing multiple clutches to die.

[Joe L.]

Re: 68 Hydraulic Clutch Fan failure....

The OP's similar post on that 'other' web site mentions having a severe vibration that goes away when the fan belt is removed. Methinks that there's some related component causing multiple clutches to die.

Mike----

An off-spec waterpump bearing/shaft assembly, bent shaft, or high TIR hub installation will "kill" a fan clutch so fast it will make your head swim.