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Hayden fan clutch observations
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=72032		 Page 1 of 1
Author:  Caddis [ Tue Oct 16, 2012 3:31 pm ]
Post subject:  Hayden fan clutch observations
I installed the Hayden 2905 fan clutch about 3 months ago, I knew it was going to affect my mileage a little, but it ended up being much more significant than I thought. I had been averaging 24-26 mpg with my normal driving, and the mileage went down to 19-22. Several weeks ago I finally did the GDE Ecotune which brought the mileage back up to 23-25'ish, couldn't seem to break 25 even on a couple of 200+ mile trips. So last week I removed the Hayden clutch and re-installed the stock clutch. I made a couple of 300 mile trips over this past weekend and I got 31 one way and 34 the other way with a strong tail-wind (hand-calculated using my GPS mileage, kept the RPM's 1800-2000). I'm going to hang onto the Hayden clutch just in case, but as I live in northern MN and never pull anything over 1000lbs, I'm sticking with the stock clutch for now.
Anyone else notice such a big difference with the Hayden fan?
Author:  CATCRD [ Tue Oct 16, 2012 6:32 pm ]
Post subject:  Re: Hayden fan clutch observations
That's weird. I installed the 2905 and got my best tank ever the next time. Mileage has been average since then.
Author:  naturist [ Tue Oct 16, 2012 8:36 pm ]
Post subject:  Re: Hayden fan clutch observations
I did the GDE ecotune at about 130,000 miles, and my mileage jumped from best ever of 30+, overall average about 25 to best ever 34.8, average around 27. When I did the Hayden fan clutch at around 147,000 miles, I didn't notice much difference, except when towing my travel trailer (8 feet x 8 feet front, 5,000 lbs fully loaded) it made a huge difference on being able to keep it cool. Mileage towing went from 14 before the ecotune to 16 after. While I have only taken a couple short trips towing since the Hayden was installed, I don't think it made much difference in mileage there, either. I will have a chance to check the mileage this coming weekend, but we're starting to get into winter diesel season and I'm headed north, so might not be able to make a good comparison.
Author:  flash7210 [ Tue Oct 16, 2012 9:21 pm ]
Post subject:  Re: Hayden fan clutch observations
When I did my t belt in July I just left my fan and clutch off.
No change to my mpg. Still average 26.
No over heating either but I dont ever tow anything.
Author:  Caddis [ Tue Oct 16, 2012 11:00 pm ]
Post subject:  Re: Hayden fan clutch observations
I'm not sure what the difference is with my vehicle, but the moment I pulled out of the shop with the hayden fan I could hear it and feel it, it was engaged at least some degree almost all the time. I don't know if it was always engaged 100%, but there was always a gale of air moving under the hood and you could hear it immediately when you started the vehicle, much more than the stock clutch.
I have a new OEM thermostat in and the temp is running right where it's supposed to and I've never seen it heat up, maybe I got a bad clutch that was engaging too low? Anyway, with fall here and winter approaching, I don't have to worry about it for a while now.
Author:  racertracer [ Wed Oct 17, 2012 8:22 am ]
Post subject:  Re: Hayden fan clutch observations
I swapped my fan and fan clutch recently and noticed no difference in MPG.
Author:  Joe Romas [ Thu Oct 18, 2012 7:36 am ]
Post subject:  Re: Hayden fan clutch observations
I installed the Hayden 2905 fan clutch and 11 blade nylon fan for a 2002- KJ with towing package.
My mileage seems to be the same or a very small tad bit higher :mrgreen:
I no longer hear the roar from the crude metal fan, no signs of overheating at all when towing with the AC on but when air movement is needed you can definetly feel the air moving under the hood.
Also after a hour or two of interstate towing in summer temperatures it only takes about half the time at idle for the exhaust gas temperature to get down to 400 degrees for a safe shutdown :SOMBRERO:
If your going to the trouble of replacing the fan clutch the nylon fan is a natural progression :JEEPIN:
Author:  painemann [ Thu Oct 18, 2012 12:30 pm ]
Post subject:  Re: Hayden fan clutch observations
Joe Romas wrote:
I installed the Hayden 2905 fan clutch and 11 blade nylon fan for a 2002- KJ with towing package.
My mileage seems to be the same or a very small tad bit higher :mrgreen:
I no longer hear the roar from the crude metal fan, no signs of overheating at all when towing with the AC on but when air movement is needed you can definetly feel the air moving under the hood.
Also after a hour or two of interstate towing in summer temperatures it only takes about half the time at idle for the exhaust gas temperature to get down to 400 degrees for a safe shutdown :SOMBRERO:
If your going to the trouble of replacing the fan clutch the nylon fan is a natural progression :JEEPIN:


I know this info is listed somewhere else but if you could post the part number of the fan you used that would be awesome. Assuming the "2905" is the part number for the Hayden clutch?
Author:  papaindigo [ Thu Oct 18, 2012 12:43 pm ]
Post subject:  Re: Hayden fan clutch observations
Hayden severe duty 2905 (ca. $51 from Amazon with free shipping) and nylon fan 52079654AD or 52079654AE for 2002-07 gas KJ latter # is most recent (ca. $65 online which is about what I paid at my local DCJ dealer but then I go way back with the parts manager).

I'd recommend a fan shroud mod for ease of future access while you are at it. Check my post at viewtopic.php?f=98&t=64278&p=709322#p709322 for several options.
Author:  Caddis [ Thu Oct 18, 2012 1:08 pm ]
Post subject:  Re: Hayden fan clutch observations
For those of you with the hayden fan, do you feel that it is engaged at all during normal operation or spinning freely? Immediately after installing it I could feel and hear the difference at the front of the engine, acceleration seemed more dogged and it was definately louder. In fact, I installed it at the same time we replaced the OEM thermostat, and as were were running the engine to warm it up and top off the coolant, you could hear the fan kick in before the gauge needle even got to it's "11:30" ideal temperature reading. My other question is that according to the Hayden website, their clutches are supposed to engage at 170, but our thermostat is set for 180-something, correct? Doesn't it make sense then that the fan should be engaged at all times once the engine is warmed up? I'm just trying to make sense of why the hayden clutch had such an immediate and significant effect on my engine efficiency/mileage when it doesn't seem to be a factor for others.
Author:  papaindigo [ Thu Oct 18, 2012 1:49 pm ]
Post subject:  Re: Hayden fan clutch observations
I have noticed no difference in mpg with the Hayden 2905 clutch and the 11 blade nylon fan compared to either the OEM clutch/metal fan or Kap's fixed flex fan. I can affirmatively state that the Hayden assembly does not run engaged all the time as I am well aware of the fan noise when the fan runs all the time based on 3 months use of Kap's rig.

That said the Hayden site says their clutch turns the fan 20-30% of the shaft speed when disengaged. Exactly how this compares to the OEM clutch/metal fan rig I don't have a clue other than I do know that OEM rig did turn at some unknown speed when the clutch was disengaged. Note also that the Hayden site says "A thermal fan clutch is engaged on a cold startup because the fluid drains into the working area when the engine is shut off. The fan clutch will slow down shortly after startup as a result of a pumping action produced by a difference in speed between the shaft and the body of the clutch."

As to the Hayden mention of the clutch engaging at 170F you need to carefully reread exactly what the Hayden web site says. That's 170F based on the air temp off the radiator which is generally 30F below engine temp. The OEM tstat is set to fully divert coolant to the readiator at 176F which would put the radiator air temp at the fan clutch at about 146F. Bottom line is a properly calebrated Hayden 2905 should not engage until the engine temp is ca. 200F which is well above the block temp for those running the OEM 176F tstat or a bit above the temp for those running the 195F Kap modified tstat. IIRC one of the main problems with the OEM fan clutch even when it was working properly is that it did not engage until somewhere around 215-220F or so. As a result the OEM rig was set to play catchup in the sense of trying to cool down an overheat cycle after it has been well started while the Hayden is set to start cool down at the very beginning of the overheat cycle.

Look in the FSM for how to read temp of the air flow off your radiator and run a check. If your Hayden 2905 does not slow down after startup as noted above or is engaging well before 170F then it's defective and needs to be replaced with one that is correctly calebrated.
Author:  MRausch82 [ Thu Oct 18, 2012 3:28 pm ]
Post subject:  Re: Hayden fan clutch observations
Caddis wrote:
For those of you with the hayden fan, do you feel that it is engaged at all during normal operation or spinning freely? Immediately after installing it I could feel and hear the difference at the front of the engine, acceleration seemed more dogged and it was definately louder. In fact, I installed it at the same time we replaced the OEM thermostat, and as were were running the engine to warm it up and top off the coolant, you could hear the fan kick in before the gauge needle even got to it's "11:30" ideal temperature reading. My other question is that according to the Hayden website, their clutches are supposed to engage at 170, but our thermostat is set for 180-something, correct? Doesn't it make sense then that the fan should be engaged at all times once the engine is warmed up? I'm just trying to make sense of why the hayden clutch had such an immediate and significant effect on my engine efficiency/mileage when it doesn't seem to be a factor for others.

Since nobody else is answering this question, I'll chime in: It sounds like, perhaps, you have a faulty clutch. It should not kick on that soon, and if it does, it should fade out. If you have a "gale force wind" noise all the time, i.e. you can hear the fan at all temperatures, all the time, that is NOT normal operation. I suspect that you got a faulty part. It happens from time to time, but should be warrantied. Good luck.
Author:  mtbdemon [ Wed Oct 24, 2012 2:09 pm ]
Post subject:  Re: Hayden fan clutch observations
Soooo, my CRD is new to me and pulled my 2500# cargo trailer this past weekend and noticed the temp gauge going over the normal of just shy of half to not quite 3/4. I assume that this should NOT be happening from all I have read. If this should not be happening, is the Hayden clutch the way to go?
I should note that it didn't over heat, it just went past where I was use to seeing it...I do have a lift,265 tires and running the GDE eco tune. Thanks!

Ken
Author:  papaindigo [ Wed Oct 24, 2012 3:24 pm ]
Post subject:  Re: Hayden fan clutch observations
Yes although it's possible that you have a temp gauge calibrated for the gasser (I did). See http://www.greendieselengineering.com/f ... st/19.page and TSB 08-043-05 . Only way to tell for sure 1) get an inexpensive IR thermostat gun and check actual temp on the top of the tstat when/if that happens again or 2) see if you can get a DCJ dealer to check. The latter is what I did but the all knowing and extremely polite service writer, when presented with a printout of the TSB and my symptoms (similar to yours), bowed up and started talking $ for diagnosis. At that point I said the only diagnosis $s you are getting from me is 10 minutes of labor associated with hooking up the scanner, pressing a few buttons, and reading the scanner screen that's going to say something like temp gauge reprogrammed or not reprogrammed and per the TSB I'm not paying $0.05 if the temp gauge gets reprogrammed. Vehicle disappeared for 15 minutes and came back with no charge.

That said some folks that have the gasser temp gauge programming and know it like that calibration as it provides more detail on actual coolant temp. They have a valid point but the key is knowing that you have the gasser temp gauge calibration.
Author:  Joe Romas [ Thu Oct 25, 2012 12:47 pm ]
Post subject:  Re: Hayden fan clutch observations
Caddis wrote:
For those of you with the hayden fan, do you feel that it is engaged at all during normal operation or spinning freely? Immediately after installing it I could feel and hear the difference at the front of the engine, acceleration seemed more dogged and it was definately louder. In fact, I installed it at the same time we replaced the OEM thermostat, and as were were running the engine to warm it up and top off the coolant, you could hear the fan kick in before the gauge needle even got to it's "11:30" ideal temperature reading. My other question is that according to the Hayden website, their clutches are supposed to engage at 170, but our thermostat is set for 180-something, correct? Doesn't it make sense then that the fan should be engaged at all times once the engine is warmed up? I'm just trying to make sense of why the hayden clutch had such an immediate and significant effect on my engine efficiency/mileage when it doesn't seem to be a factor for others.


I believe our thermostats open at 176 degrees and understand the Hayden is set for 176 also. The original fan clutch was over 200 for the gasoline engine.
There were a lot of bad fan clutches on the 05's that kind of points to a bad batch from the git go so maybe yours was not moving enough air :frankie:
Author:  papaindigo [ Fri Oct 26, 2012 8:24 am ]
Post subject:  Re: Hayden fan clutch observations
Joe is right about the 05 fan clutch as reports of bad fan clutches or at least "early" fan clutch failures seem to be more common for the 05 model year.

However, see my post above about the operation temperature of the fan clutch. There is a metal (probably bimetal) coil in the front outside of the clutch that functions as a termometer to lock/unlock the clutch. The trigger is the air temperature off the radiator which is about 30F below the coolant temperature in the engine block (see discussion on Hayden web site). The triggering air temp for the Hayden is set for 170F (ca. 200F block coolant temp). The trigger point for the OEM fan as implied in the FSM clutch testing method is in the 195-205F range (225-235F block coolant temp). Assuming those OEM fan cut in figures are correct IMHO there is a basic design flaw in the OEM fan clutch. Consider:
1. the point of a clutched fan is to minimize parasitic drag on the engine when the fan in not needed which increases mpg a tiny bit while at the same time providing for fan operation if the engine starts to overheat.
2. ideally it's better to stop overheating early in the process as opposed to waiting until overheating is well underway in which case the system has to stop the overheating and bring the coolant temperature back down to normal.
3. per GDE the ECU triggers the start of a fuel cut to prevent overheating at a coolant temperature of 225F which implies the software is calibrated to consider overheating well underway at 225F
Putting this together IMHO the OEM fan clutch is set to engage at least 15F too high and well after the beginning of the overheating curve in contrast to the Hayden setting which begins to engage the fan right at the beginning of that curve.
Author:  UFO [ Tue Oct 30, 2012 11:36 am ]
Post subject:  Re: Hayden fan clutch observations
I replaced my fan clutch with the timing belt replacement, and now the temperature gauge is steady climbing the mountains now. The old fan clutch has been bad the whole time I've owned the Jeep from 36k miles. Perhaps a 10% drop in mileage, hard to say since my wife is the main driver.
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