I never had a problem with belt slip.

Is your PS pump properly tensioned?

 

Should be.. I just put them back on and retensioned when I worked through the whole rear main seal debacle. There's not more than 1/2" of deflection in the center, I believe that's the spec.

I just don't think the belts are designed to turn a locked-in fan that fast. If you've heard one with the engine speed at 3k, you'd understand. Normally the clutch would keep it at a reasonable speed throughout all engine speeds.

 

I drove my truck home over 100 miles at 70+ mph with the T-19!
It made a lot of noise, but no belt squealing.

You should be okay at highway speeds and light throttle with no fan.

 

Hmm, maybe they are loose. I'm probably due for putting new belts on soon, anyways.. I bought new belts for the truck when I first bought it, but hardly any of them fit after I took my air pumps off and A/C off. So now I have a pile of belts I can't use and the fan only got one new belt, the other is old. I'm going to do it right eventually and buy all new belts.

I drove to the grocery store which is in town, and the engine / coolant temp didn't seem to care that there was no fan. I rarely find myself in sitting traffic, but as soon as I say that, there will probably be some crazy accident on I-25 for my morning commute Monday.

 

It's the imbalance out on the end of the shaft that kills the water pump. So if your clutch just drags or locks up square and true, it creates parasitic drag and noise. If it fails into a cocked situation then you have the bad imbalance.

You can rebuild these clutch hubs on the cheap, if its not too badly gone, split it apart, clean it up and refill with friction fluid. Toyota sell the fluid in small bottles really cheap, from memory 2 bottles are needed for a large hub.

 

I too am a member of the failed 460 fan clutch club and have experienced the roar of the fan, and squeal of the belt at 3,000 RPM, when the original equipment (#1) fan clutch seized up.

The first replacement fan clutch I installed (#2) was interesting. Below 5,000 ft. altitude it "released" at 2,300 RPM, hot or cold it didn't matter, and no matter how hot it got it would not hook back up until RPM's dropped below 1,200. Strangely, above 6,000 ft. altitude it never would release, I could push it to 3,000 RPM and it'd just roar and squeal...the only reason I could figure for that was the thinner air at altitude?

#3 never would hook up.

The one I have now (#4) seems to work well enough.

 

Youse guys are making a real good case for electric fans. Personally I've never had a fan clutch fail, but maybe I just jinxed that.

 

Clutch fans fail, I have had several do it. They work good with good longevity, but like everything else it's difficult sometimes to get a quality part to replace it. The large ones for the diesels like my truck are around $140, and they are known to fail or not work right out of the box.

I tried the electric fan deal. 2 aftermarket 16 inch fans would not cool my diesel well enough on a long pull with a load behind it. And it also opened up a can of worms with the A/C system and the alternator not being large enough. Some people have had success using Ford OEM electric fans from Taurus and Windstar vans. But they draw even more current, thus the need to swap to a 3g when doing all this.

I just took all that out and put my original fan back in place, and put brackets on it to lock it solid and bypass the clutch. No overheating problems now. I am sure I am losing a little bit of efficiency but everything is a trade-off. This original fan I have is 23 inches in diameter.

 

Interesting that two 16" electric fans wouldn't cool it but the engine-driven fan will. And on a long pull, meaning that it is on the road, not idling.

I understand the can of worms, but I'm already going to be half-way there as I'm going with the 3G and a power-distribution box. So all of the wiring changes are under the hood and separate from the rest of the vehicle's wiring. So, did you sell the fans and alternator?

 

Hmm, maybe I'll try to pick up a Taurus / Windstar electric fan when I'm at the junkyard. I suppose this might yield a fraction of a MPG, but every little bit helps. Plus, I won't miss that loud roar of the fan first thing in the morning. Do I get one off a 3.0 or 3.8 engine? I think my alternator came off a '95 Windstar with a 3.8L.

 

Yeah, the fan blades on a clutch type fan are pitched much more aggressively than those on a direct drive fan, so when the clutch locks up, they make a lot of noise.

The newer diesel trucks have electrically controlled fan clutches that are designed to help speed up the fan as needed, like a long pull or when the A/C is in use. Those fans pull a LOT of air. You would be surprised at how clogged the core can get on these radiators, particularly when they are used in a dusty environment.... This not only hurts the cooling capacity of the radiator, but also lowers the cooling effects in the A/C condensor and intercooler even when these aren't clogged with dirt. This hurts the engine performance, and can even lead to engine damage from running too warm.


Electric fans may sound like a good alternative, but they rarely cool as well as a clutch type fan, and put an extra load on the charging system that can cause as much (or more) drag on the belt drive than what a clutch type fan would do.

While it is true that the radiator doesn't typically need a fan at speeds of ~35 MPH or more, the A/C condensor can. This is why many vehicles equipped with electric fans from the factory, have more than 1. One of these is typically tied into the A/C, and runs full time when the A/C is in use. This aspect is worth mentioning, since the factory A/C in these trucks was designed to also run in the winter, when the defrost setting is used, as it helps to keep the inside glass from fogging up.

 

The fans are still hanging on the shop wall. I will probably use them on another project with a smaller engine. I was using the stock alternator that came on the diesels, it was a 100 amp unit. I was not quite keeping up at night with the A/C on, dash blower on high, and the headlights on. Of course with the A/C on that made the radiator fans come on. I forgot about this when I first wired the fans up and had a little "episode" with the high pressure relief valve in the A/C system popping off one day making a big mess under the hood.

 

Yep, RW is right - they wire the 2nd fan in parallel with the A/C compressor clutch for that very reason. Anyway, I'm going to consider electric fans, so if someone finds out what fans are a good fit across the early radiators (from about 84 the radiators were a different size) I'd like to know.

 

Advance Auto has the Imperial (Made in US I think) severe duty clutch for $39 to fit '85 460.
Also, if stored flat the fluid will migrate to the front and the clutch won't work right out of the box. I've found letting it sit on edge for a day before installation gets it working right.
On the other hand, Mercedes supposedly says it will never work right again if stored flat. YMMV

 

I've read that before and always take care to store them on edge. But, can anyone tell me how to ship one such that it'll always be on edge???



Didn't think so. IOW, all the ones we buy have been laid flat at some point?