Fan part help please

[cybindustries]

Hoping someone can help. So my fan was wobbly upon removing it I found the rubber gromet piece to be torn and missing a chunk. There is a part number on it. But it pulls up the whole fan clutch. Does anyone have a lead on the part or a suitable replacment.

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[Awesomeness]

The TMs now instruct you to ditch the old fan and clutch, and replace them with newer versions. The new fan has a solid one piece steel center hub, with the plastic fan permanently attached. Because of that, I don't think the rubber discs for the old style hub are made or stocked anywhere any longer.

 

[cybindustries]

Shoot ok. I haven't been able to find the new style clutch. Found the new style fan though.

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[Awesomeness]

The new style clutch wasn't that hard to find when I replaced mine last year. I think it's still in production actually. Check the part numbers in my spreadsheet, here in my post signature.

 

[mkcoen]

Adventure Driven and I both lost our fan clutches (old style) at highway speed taking out the radiators when it happened. I recommend everyone change them out whether they’re bad or not just to prevent a future mishap. It was a stupid design to begin with.

 

[Awesomeness]

Adventure Driven and I both lost our fan clutches (old style) at highway speed taking out the radiators when it happened. I recommend everyone change them out whether they’re bad or not just to prevent a future mishap. It was a stupid design to begin with.

I don't think the design was bad, as much as it was never meant to go 20+ years without having the rubber ring replaced. The new fan generates a lot more vibration, because it has no damping like the old one, though it can likely survive a lifetime of the Army's finest poor maintenance.

 

[simp5782]

You can eBay search RCSK14621 for the newer clutch. The MilBot company will take a reasonable offer on the clutch. or contact swampdonkey he is a local surplus guy for him and can acquire it cheaper alot of times.

 

[mkcoen]

I don't think the design was bad, as much as it was never meant to go 20+ years without having the rubber ring replaced.

Sorry but I think a multi-piece conglomeration between the fan and clutch was just a disaster waiting to happen. The new setup with the fan bolted directly to the clutch gives you far less opportunity for failure. The difference between how much vibration you have on these engines would be negligible.

 

[Ohiobenz]

Can the rubber part just be eliminated or is a new style part required?

 

[Awesomeness]

Sorry but I think a multi-piece conglomeration between the fan and clutch was just a disaster waiting to happen. The new setup with the fan bolted directly to the clutch gives you far less opportunity for failure. The difference between how much vibration you have on these engines would be negligible.

I can tell a clear difference when I changed mine. I think the only reason it survives is that the fan generally doesn't run for very long.

It's also really naive to call a system that worked reasonably well on 100,000 trucks for a couple decades "a disaster" and a "stupid design". It completely ignores the reality that they worked quite well for a long time on a huge number of trucks, and spreads poorly thought out ideas. If you look up the statistics of vehicle-related failures for things that are perceived as having "good reliability" or a "poor design" they are extremely small (fractions of a percent). So it's wise to show some objectivity and restraint. A good example is the Ford Pinto, of gas-tank-exploding fame ( https://en.wikipedia.org/wiki/Ford_Pinto ): "its fuel-tank design attracted both media and government attention after several deadly fires related to rear-end collisions. A subsequent analysis of the overall safety of the vehicle indicated its safety was comparable to other 1970s subcompact cars."

I'm compelled to offer this rebuttal every time I see people claiming such things. It usually just means you don't understand.

Can the rubber part just be eliminated or is a new style part required?

You can't just remove it and bolt the parts back together well, no. You could make a replacement, which would likely last another 10-20 years, but the effort would probably cost more than replacing the fan and clutch.

 

[cybindustries]

I'm just trying to fix it with out spending the 600+ for a new clutch and fan. My truck only has 2200 verified miles on it. The rubber just aged and cracked.

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[Pointman0853]

Where I got my replacement parts:

https://kit-masters.com/identify-your-kysor-clutch/

This is their specialty...

Pointman

 

[mkcoen]

It's also really naive to call a system that worked reasonably well on 100,000 trucks for a couple decades "a disaster" and a "stupid design". It completely ignores the reality that they worked quite well for a long time on a huge number of trucks.

If it worked so well why did the military change it? The more parts you add to an equation the more opportunity you have for failure.

 

[Awesomeness]

I'm just trying to fix it with out spending the 600+ for a new clutch and fan. My truck only has 2200 verified miles on it. The rubber just aged and cracked.

I understand that, though to some extent these large old trucks constantly require "couple hundred dollar" fixes. Mine seems to every few months.

It all really depends on what you have access to (e.g. tools, surplus parts, time, etc.).

The bolt pattern on the new steel-hubbed fan is just slightly different than the old one. About half the diameter of the bolts, if I remember correctly. If you know a machinist, you could take a new steel-hubbed fan and have the holes elongated into slots that would match the old clutch's bolt pattern. A regular machine shop is probably going to charge $100/hr to do that, meaning it would cost $100-200. You might be able to find a friendly less-formal machine shop that would do it for less.

Before I did that, I would think about why they changed the bolt pattern in the first place, and are you putting anything in danger by using the mismatch that they intentionally did not want you to do? It could just be that they selected a different off-the-shelf clutch as an upgrade, and so it was a little bigger (with bigger bolt pattern), or something. But it seems like the spent a lot of time and money to make the new parts different, so you are intentionally undoing what they did without knowing why.

 

[Awesomeness]

If it worked so well why did the military change it? The more parts you add to an equation the more opportunity you have for failure.

What I'm pointing out is that these are small course corrections. They are "We've had a few dozen or couple hundred failures, out of 100,000, so we should see if we can make a change." They are not "This is a terrible stupid design and MOST or MANY wreck stuff, so let's get right on changing it now." Even the percentage of failures that drove them to "get right on it now" and change the driveshafts on EVERY truck was probably small (and it wasn't even concerning enough for them to go with the engineer's recommended setup, and instead they chose to just apply the temporary workaround as a permanent solution, and deal with failures that would inevitably come).

Nothing is ever "better" or "worse", though it can have pro's and con's that better support your particular situation or use. We perform engineering trade-off studies like this all the time. I could imagine one where it was decided that the increased vibration from a rigidly mounted fan shorting the life of the crank bearings in the engine by 20% is acceptable if it means that 5 trucks a year do not suffer a catastrophic fan failure in the field that strands a truck (potentially in combat). A lot of thought goes into this stuff, it's not just a college intern rolling some dice.

 

[Green Mountain Boys]

I had to replace mine last year. I got the new style fan and fan clutch from Equipment Parts Sales. The service was fast and the price was the best I could find at the time. The sales guy's name was Nathan Fulkroad. I think they are located in PA if I remember.

 

[scottmandu]

I would say it's not a stupid design as it's lasted 20+ years. It is not known the motivation for changing the fan clutch style. I could very well have been Kysor wanted to save money by offering a design that was less costly to manufacture, as that fan clutch style was used on a number of different vehicles. Mileage doesn't mean much to a rubber component, as rubber starts to deteriorate the day it is release from it's mold. I find it interesting that some people buy a 20+ year old truck with under 5000 miles and expect it to be in the same condition as a year old truck with the same miles.

 

[simp5782]

I would say it's not a stupid design as it's lasted 20+ years. It is not known the motivation for changing the fan clutch style. I could very well have been Kysor wanted to save money by offering a design that was less costly to manufacture, as that fan clutch style was used on a number of different vehicles. Mileage doesn't mean much to a rubber component, as rubber starts to deteriorate the day it is release from it's mold. I find it interesting that some people buy a 20+ year old truck with under 5000 miles and expect it to be in the same condition as a year old truck with the same miles.

oh you know that line. "but it is a rebuilt truck" or "its only got 5000 miles". Very few components on any of the surplus MVs wear out due to useage. It is mostly from sitting which we know is the worst thing for them. Plus alot of owners don't believe that their truck may have sat for 10 years in the back 40 before it was sold.

 

[Adventure Driven]

We were left stranded because of the old style fan and clutch went south and nicked my radiator, thus leaking antifreeze everywhere. We recommend to everyone to change the old ones to new parts, pulling the radiator in the street with coolant dripping in your face is no fun.

Seth

 

[HotTubTimeMachine]

I lost my fan due to old rubber. The doughnut split and flung out so the fan became unsupported and unbalanced then cut the airline to the clutch. But, not before wedging the clutch air inlet into the spacer and ruining it.

I’m trying a different approach and decided to machine a new clutch spacer that only uses rubber on one side.

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