Fan flew off and took out the radiator

[ntaylor8]

Yup thats what happened. I turned off the engine in a parking lot and heard a big clank! from under the hood. When i got out and took a look i saw that the fan and clutch assembly had unscrewed from the water pump flew forward and the radiator was no more.
I am currently thinking that maybe the fan clutch locked and the inertia of the fan was great enough for it to keep spinning and unthread itself. I am figuring that i will buy a new fan clutch and be done with it but any suggestions would be greatly appreciated.

 

[6 Nebraska IDIs]

You're exactly right. We had this happen on my dads 90 when it was only a couple years old. Completely wiped out the radiator. The fan was literally sticking all the way through the radiator.
Sucks for you because these clutches are now very expensive, where back then you could get them pretty easily from a salvage yard and they were like new.

 

[icanfixall]

MS Tech in Babylon New York sells a modified fan clutch thats great. It locks up at 210 degrees and really starts cooling down the motor fast. When you install it just like any others use Locktite blue on the threads and it will not come off again but will be easy to take off with thw wrenches. You will also need a fan. There is no way you can straighten the fan after it eats the radiator. Being out of round and unbalanced it will ruin the water pump bearings fast.

 

[6.9poweredscout]

seesh...i'm gonna be paying like $550 for a custom alumnum radiator for my scout, i really hope this won't happen!

-Jon

 

[FordGuy100]

Just out of curiosity, and off topic, but when does the stock thermostate open? I have never seen my truck run over 200*. I was pulling a boat (4-5K pounds), up some really long steep grades, and it would go up to 200*, but I would be forced to downshift into 3rd (well wasnt forced, but I was loosing some speed. I started at the bottom of a good 7% couple mile grade at 65mph in 4th, towards the top, I was down to just over 50mph, so I went into 3rd, went right back up to 55mpg in no time), anyways going up that grade, after I downshifted, the water temp dropped to 180*. EGT's where around 1050* the whole time pulling the grade, and boost was at around 8psi.

 

[Mr_Roboto]

The fan clutch nut just wasn't secured. It would be normal for the fan clutch to be engaged when the motor shuts off, if the temp conditions are right.

Lock-tite on the threads and tighten with the proper wrenches.

 

[RLDSL]

Tighten with the proper wrenches and torque the thing down. There is a spot in the fan clutch wrench for a 1/2" drive ratchet to fit into, that is for your torque wrench to go in for torquing the thing down. The spec gives a whole lot of lee way, but it's 45-I think160 ft lbs.
If you put locktite on that sucker and get someone to hold the pulley holding wrench in the kit, you'll be lucky to get 60-90 ft lbs on that thing and somebody WILL get hurt but it will be on to where it's not going anywhere.

 

[icanfixall]

The stock Ford or International thermostat starts to open at 192 degrees. It has a tolerance of +0 to - 7 degrees. Its fully open at 212 degrees. It has a minumum sleeve opening of 0.26 in the full open position. So in otherwords its got to be open around 1/4 inch to be correct. Further on in my Navistar service manual it states the start to open temp is 192 degrees +/-5 degrees. Kinda confusing isn't it. I once cut the rubber sleeve gasket off near the fully closed position and that motor ran much cooler. I think because the thermostat was capable of passing more coolant without this rubber sleeve in the flow path. The design of this rubber is to close the thermostat better than the metal to metal can do.

 

[FordGuy100]

The stock Ford or International thermostat starts to open at 192 degrees. It has a tolerance of +0 to - 7 degrees. Its fully open at 212 degrees. It has a minumum sleeve opening of 0.26 in the full open position. So in otherwords its got to be open around 1/4 inch to be correct. Further on in my Navistar service manual it states the start to open temp is 192 degrees +/-5 degrees. Kinda confusing isn't it. I once cut the rubber sleeve gasket off near the fully closed position and that motor ran much cooler. I think because the thermostat was capable of passing more coolant without this rubber sleeve in the flow path. The design of this rubber is to close the thermostat better than the metal to metal can do.

So do you suppose my thermostat is bad?

 

[6.9poweredscout]

...wait wait, isnt the fan clutch nut reverse thread??? how could it come off unless the motor ran backwards???

 

[icanfixall]

Yes... The nut is a left hand thread. When the motor stops rotation the weight and dynamics of the fan continue to turn and that backs off the threads. While looking down on the nut you have to turn it towards the passenger fender to tighten. Push it towards the drivers fender and it will loosen up and spin off into the netherlands.

 

[6.9poweredscout]

wait...which way does the motor spin? i though it was reverse thread so the rotation would tighten it??

-Jon

 

[Classicfordguy]

Motor turns clockwise when looking at it from the front of the truck. The fan clutch nut loosens clockwise as well so when the diesel engine stops sudenly on shutdown the fan keeps going and backs itself off. If you ever forget and need to figure out which way the motor turns look at the fan blades, they're pulling air through the radiator.

-Rob

 

[6.9poweredscout]

Motor turns clockwise when looking at it from the front of the truck. The fan clutch nut loosens clockwise as well so when the diesel engine stops sudenly on shutdown the fan keeps going and backs itself off. If you ever forget and need to figure out which way the motor turns look at the fan blades, they're pulling air through the radiator.

-Rob

thanks, sometimes i overthink and confuse myself...

-Jon