Fan Clutch Issue

[02cummins25mpg]

Replaced the fan clutch over the summer and have noticed a drop in fuel milage. Saw the video of Mike stopping his fan, got me to wondering, so I went and checked mine same as Mike. Chewed the end off a 2 x 4. Question is how do you loosen one up? It is not frozen up it is just really tight causing the fan to be under load all of the time...

[dripley]

mine is oe and acts like yours. i dont think i have ever seen one spin as free as Mike's. i can still hear mine when it cuts in. as someone on here described, like a turbo prop running. impossible to miss. if i spin mine it will turn maybe 1 1/2 revelotions and stop. engine not running for the spin test.

[02cummins25mpg]

if I try to spin mine it will only go MAYBE a 1/4 of a turn.

[CUMMINSDIESELPWR]

when i start up i can hear it but then it fades down as it isnt needed i think through centrfugal forces plus temp demand. i know it does its job as in the summer the temp is stable

[dripley]

from reading your sig you have exceptional mileage. how far did it drop?i might have exagerated how far mine spins but is definately more than 1/4. i dont believe mine has ever freespun as good as Mike's did in the video. i think we need more input from others.

[02cummins25mpg]

Last week went on an 1100 mile trip, 90% interstate, @ 60-65 on cruise and only got 17.9. Could here the turbo the whole time. I knew it was working too hard to just be cruising down the interstate. I was thinking about removing and cleaning the I/C. Then I saw that video and thought that might be my problem. If I cant figure out how to loosen it up the fan may end up in the toolbox.

[CUMMINSDIESELPWR]

cruising at 65 i can hear my turbo, but im only putting out i think 6psi sound isnt a reliable indicator of what psi its putting out

[dripley]

do you have a boost gauge to see how hard the turbo was working. at 60 to 65 on level ground in od i am only pushing maybe 3 pounds. can you tell when your fan kicks in? if it is running all the time it is quite loud. maybe thats what you are hearing instead of the turbo.

--- Update to the previous post...

cruising at 65 i can hear my turbo, but im only putting out i think 6psi sound isnt a reliable indicator of what psi its putting out

how free does your fan spin?

[02cummins25mpg]

Been trying to get back to the really good mpg's that I got about a year ago. In the last 6 months or so have installed new injectors, found a boost leak, and replaced the fan clutch. Truck runs better, has more seat of the pants power, but still cant get back to the 24-25 mpg

--- Update to the previous post...

I believe the fan is spinning all of the time. I know I can hear it when I take off. Could be the fan I hear or the fan causing the motor to work harder causing more boost:shrug:

[dripley]

20mpg is the best i have ever seen on mine. i do run the speed limit plus 5 or 10 depending on conditions. 65 to 75 is a norm for me. truck weighs about 7500 when i travel and the rv275's have got me just above 19. nedd torun a few more tanks and see if that hold or was just a fluke. 24 or 25 would blow my mind. not sure how much drag the fan alone would put on the engine.

[02cummins25mpg]

Any ideas how to loosen up the fan clutch???

[dripley]

i dont have a clue. not really sure you can. i am hoping someone jumps in here a tells a little more on the subject.

[CUMMINSDIESELPWR]

do you have a boost gauge to see how hard the turbo was working. at 60 to 65 on level ground in od i am only pushing maybe 3 pounds. can you tell when your fan kicks in? if it is running all the time it is quite loud. maybe thats what you are hearing instead of the turbo.

--- Update to the previous post...

how free does your fan spin?

let me check, its about 30deg outside brb

[dripley]

Been trying to get back to the really good mpg's that I got about a year ago. In the last 6 months or so have installed new injectors, found a boost leak, and replaced the fan clutch. Truck runs better, has more seat of the pants power, but still cant get back to the 24-25 mpg

--- Update to the previous post...

I believe the fan is spinning all of the time. I know I can hear it when I take off. Could be the fan I hear or the fan causing the motor to work harder causing more boost:shrug:

i dont understand why, but i have read here and experianced my self, the fan tends to come fairly often upon initial start up. mine has since it was new, mainly in warmer weather. thats why i have never given it second thought. i here come on and off. i hardly hear my turbo unless i am on the throttle pretty good. the two noises are totally differant though. i hear the fan come on and off pulling 7%grade hauling my rv, turbo is whining pretty good also.

[CUMMINSDIESELPWR]

well it was 19 and engine cold, fan may have turned less than a quarter and was nice and stiff. i also have the silencer ring removed from the turbo

[dripley]

i could understand them being stiffer in the cold weather until they warm up. Mikey must have some secret going on with his. maybe he will share that with us or just buy us all one like his for Christmas.

[02cummins25mpg]

I will be glad to swap fans with the Guru...:lmao:I was hoping he would chime in...

[dripley]

it was 35* here this am. i started my truck, idled out of the rv park, took about 4 minutes, hit the highway and my fan was engaged. it took about 30 seconds and it disengaged. that is fairly normal for my truck, though it does not happen every morning. the fan is spinning just like the other day and i am not going to stick anything in it to see what happens.

[Mopar1973Man]

I will be glad to swap fans with the Guru...:lmao:I was hoping he would chime in...

No... I'm keeping my high MPG fan... Thank you... I guess its time to consider replacing the fan if its chewing the end of a 2x4... My buddies 92 Dodge was locked solid what I can tell that happens is over a period of time the clutch leaks out the oil inside and then seizes up on the shaft. He's fan was solid and you could turn the engine with the fan...

[dripley]

i spent about 45 minutes researching fan clutches. ther was alot of info. the best i could get from reading it all was that when cold you should be able to spin the fan from 1/4 to 1 reveloution. if the bearings are tight you are good. so most of us are ok. As far as fre spinning like Mikes there were differing opinions on how much free spin was ok even if the bearings are tight. the way i see it as long as it is not locked up(by that i mean you can spin it, engine off) and hear it come on and off you should be ok. if you are overheating thats a differant story.jou can just google fan clutch trouble shooting like i did and see what you can find out. me i am satisfied mine is working fine. if you can gnaw off a 2X4 thats a differant story. mine might but i dont think i am going to try.