Clutch Fan - Montana Owners Club

Trailer Trash 2 · 07-03-2006, 04:26 PM

Is there a way that a person can check the working order of the clutch fan, without having it under load and at temp and on the work bench.

pud2 · 07-04-2006, 04:36 AM

Don i don't think so. I Have had one go out before on my 95 f150 and you can tell by looking and turning the fan as soon as you kill the engine if the fan is still spinning or if you can spin it by hand pretty easy then it is probably bad. I think mine is going out on my truck know because it sounds like it is slipping or at the point were the t-stat on these things tell it to lock up and pull more air. It all most sounds like the trans is slipping but i know that isn't it because there is no change in my rpm. The reason i havn't replaced yet is they are kind of expensive. Don't know if this helps but if you find another way let me kmow.

Trailer Trash 2 · 07-04-2006, 06:51 AM

Thanks for the tip pud2 I'll go out and try what you sugested, it sounds like a logical test to me.

panhandlevern · 07-04-2006, 11:27 AM

Mine went out and I didn't know what was wrong for a while, the engine red lite would come on when I was pulling a mountain pass, or when the engine was really working. Changed the fan clutch and no more problems. Though I don't know of a way to really test it without getting the engine hot.
Panhanlevern
02 F250 PSD
00 Montana 3280RL

trukdoc · 07-04-2006, 01:37 PM

This is getting harder to do with the newer trucks packing the engines in like sardines. But try to grab the fan on eack side and see if you can rock the fan on the shaft. Anything but just a little movement is a clutch going bad.
Hope this helps.

Wrenchtraveller · 07-04-2006, 02:19 PM

I think if the clutch was not working, you would see your temp guage move up while you were pulling a good grade. All my Fords, and I have had many, always pulled grades without the temp. guage moveing. The newer clutch fans are much quieter and my 04 PSD and 05 V10, I could not hear the clutch fan kick in. My 88 460, WOW, the clutch fan was super loud on that truck.

pud2 · 07-04-2006, 03:36 PM

Don i did forget to mention that the engine needs to be up to temp before you try that test. I would drive it a little and then check as soon as you shut it off.

Trailer Trash 2 · 07-05-2006, 04:21 AM

OK this is what I found out so far as far as checking the opperation of the fan I'll share with all of those interested from the Diesmans web page.

You need to get the engine fully warmed up. In neutral, run the engine speed up to 1800 RPM. The fan clutch should lock up within 15 minutes and stay locked in for up to 5 minutes. It should start to freewheel for 5-15 minutes before locking up again. If the engine is stone cold the fan should turn by hand with some resistance. After a couple of minutes of driving from a cold start the viscous oil in the clutch should be distributed enough to allow the fan to continue spinning after the engine is shut off.

I will be checking this today I couldn't yesterday with the 4th going on.
Pud2 thanks you were right on it.
Thanks to all the input from all.

TT2

pud2 · 07-05-2006, 10:56 AM

Good luck Don. Let us know what happen. This is a great place for Q&A.

hodag · 07-06-2006, 03:48 PM

have a 1999 350. cluch went out 65k mi. only showed up pulling hard grades and 80-90 temps. pulled over when temp.guage spiked, 5 min. and temp.was normal. garage put in thermo. which i was questioning,because that is the type job i like doing. i ask about fan clutch and how do you check it. was told same as was suggested.i asked if thermo. did not fix problem what was next? fan clutch. towed more grades and more hot temps. bought cluch in moab, utah.$260,no bargains in that town. easy job to replace. large nut on end of shaft is reg. thread, loosen counter clockwise. tap with cold chisel few times to break loose. 4 bolts hold fan to cluch. i was able to wiggle cluch out and new one back in pretty easy. now hear fan running at higher speeds when it is supposed to. pulled vail pass 11k. ft. no problems.

Trailer Trash 2 · 07-09-2006, 03:32 PM

With the motor cold I turned the fan by hand and did get some resistance,
then I got the truck up to opperatin temp and brought it home poped the hood and had the DW hold the idel at 1800 rpm's for a long time, and the fan did not engage. it was spinning but not the loud roar that a person normally hears when it engages, and the fan spun for a while after the motor was turned off. maybe about 10 complete turns at the most.

Still checking though.

TT2

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