Should you get a heavy duty fan clutch?

[machoheadgames]

I don’t think my Mopar fan clutch is operating correctly, but I wanted to ask in case I’m wrong.

Here’s a video of it, imo, not properly disengaged after sitting all night (current temp is 43*).

https://vimeo.com/915562573?share=copy

I bought the part three years ago to replace PO’s failed electric fan. This part may be why my gas mileage has dropped…it seemed too extreme to only be a winter fuel issue (if that’s even a thing in Tucson)

I may get this clutch if your are still having good luck with it @freedom_in_4low

View attachment 503102

This seems like normal operation to me....

And based on my experience with my Jeep, Ranger, Frontiers, and Tacoma (which all had fan clutches), they all make a roar at startup and then quiet down after just a bit of driving. That is because the fluid is thick when it's cold and it takes a bit to disperse and disengage the clutch to idle levels (which is how it should stay until the radiator warm temp causes lockup again)

Are you experiencing any sort of temperature problems, or any sort of unusual fan roaring at times when it didn't in the past?

 

[MikeE024]

This seems like normal operation to me....

And based on my experience with my Jeep, Ranger, Frontiers, and Tacoma (which all had fan clutches), they all make a roar at startup and then quiet down after just a bit of driving. That is because the fluid is thick when it's cold and it takes a bit to disperse and disengage the clutch to idle levels (which is how it should stay until the radiator warm temp causes lockup again)

Are you experiencing any sort of temperature problems, or any sort of unusual fan roaring at times when it didn't in the past?

No temperature issues. I was checking the WP pulley for play since I'm diagnosing what sounds like a raspy bearing issue around 3600 RPMs...then I noticed the fan didn't turn much when I manually moved it...and the wheels in my head started turning.

 

[machoheadgames]

No temperature issues. I was checking the WP pulley for play since I'm diagnosing what sounds like a raspy bearing issue around 3600 RPMs...then I noticed the fan didn't turn much when I manually moved it...and the wheels in my head started turning.

In that case I would imagine the clutch is functioning fine thermally, but hard to say from afar.

The Hayden I tried would basically be loud all the time. Extremely obnoxious. I have the older 4-bolt flange style so there was no "extreme duty" to try which was supposed to be more like stock Mopar, but in this thread plenty of people said it wasn't that great anyways. USMW seems to be more like stock.

But definitely being stiff when cold and roaring at startup for a bit is normal. If it doesn't quiet down soon, then that is for sure abnormal. Honestly other than fluid leaks, I'm not really sure how fan clutches really fail. There is not much to them besides bearings, fluid, the spring, and channels inside that the fluid flows through.

 

[freedom_in_4low]

This seems like normal operation to me....

I agree.

And based on my experience with my Jeep, Ranger, Frontiers, and Tacoma (which all had fan clutches), they all make a roar at startup and then quiet down after just a bit of driving. That is because the fluid is thick when it's cold and it takes a bit to disperse and disengage the clutch to idle levels (which is how it should stay until the radiator warm temp causes lockup again)

Also agree. The difference for me is that with the Hayden clutches (I tried both the 2771 and 2791), it didn't unlock after initial startup until it was almost warm enough that it was time to engage again. Almost like it stayed locked until the first time it engaged, then it would release. But the time wheeling in Colorado, it never even got warm enough to engage the first time, so it just roared all day.

Are you experiencing any sort of temperature problems, or any sort of unusual fan roaring at times when it didn't in the past?

Switching to the Hayden is when i experienced roaring at times I didn't in the past.

The FSM details a troubleshooting sequence for the fan clutch and if you infer from that, there's not a really easy way to condemn one unless it's REALLY toast. It calls for putting a temperature probe between the radiator and fan and measuring the fan speed with a tachometer and using a piece of cardboard to manipulate the airflow - the speed should increase noticeably as the temperature goes over 170, and then slow down again with temperatures below 170. No mention of any spinning the fan by hand or sticking a rolled up newspaper into it or any of the other traditional mythology.

 

[MikeE024]

This seems like normal operation to me....

And based on my experience with my Jeep, Ranger, Frontiers, and Tacoma (which all had fan clutches), they all make a roar at startup and then quiet down after just a bit of driving. That is because the fluid is thick when it's cold and it takes a bit to disperse and disengage the clutch to idle levels (which is how it should stay until the radiator warm temp causes lockup again)

Are you experiencing any sort of temperature problems, or any sort of unusual fan roaring at times when it didn't in the past?

I agree.

I wasn't sure if it would be so cut and dry since my issue would be the fan staying locked. And, the thermostat sets the floor even if the fan is turning. It does take longer to warm up but I thought it was due to the colder weather. Multiple variables involved.

Keep in mind that I haven't had a viscous fan to compare my noise to. The rig came with an e-fan.

I asked in here for a reason, and I appreciate the insight.

The FSM details a troubleshooting sequence for the fan clutch and if you infer from that, there's not a really easy way to condemn one unless it's REALLY toast. It calls for putting a temperature probe between the radiator and fan and measuring the fan speed with a tachometer and using a piece of cardboard to manipulate the airflow - the speed should increase noticeably as the temperature goes over 170, and then slow down again with temperatures below 170.

Good to know this. I have a gauge for measuring fan speed. But, I'd rather just throw a cheap clutch in before dealing with the probe (that I don't have) and cardboard nonsense especially when I have coolers in front of the condenser.

No mention of any spinning the fan by hand or sticking a rolled up newspaper into it or any of the other traditional mythology.

BTW, the folded paper method, rather than the roll of newspaper method, is a great way to check a fan clutch that won't lock up. But, that checks the clutch when you have the opposite of my issue.

And there's a good reason why the FSM will never provide instructions like the paper method —-> LIABILITY (not because it's not legit).

 

[Zorba]

FWIW: I've noticed my 2771 will not unlock until the engine speed is over about 3K for a bit. As soon as it drops below that, it will lock up again, regardless of temperature. As I'm seeing positive benefits from the increased airflow, I'm not concerned about it - the noise doesn't bother me.

 

[MikeE024]

FWIW: I've noticed my 2771 will not unlock until the engine speed is over about 3K for a bit. As soon as it drops below that, it will lock up again, regardless of temperature. As I'm seeing positive benefits from the increased airflow, I'm not concerned about it - the noise doesn't bother me.

Good to know thanks man. This thread has been super awesome.

 

[Zorba]

Good to know thanks man. This thread has been super awesome.

A clarification: I say "As soon as it drops below that, it will lock up again", but I don't know if that means it will lock at 2500 (to pull a random RPM outta my ass) or hold off til its lower. In my case, I've observed when its unlocked at about 3K, then I come to a stop sign, then its re-locked as I pull away. In other words, I don't have it completely quantified - and in normal driving, I'm not above 3K very often.

 

[MikeE024]

The reason I looked into the fan clutch is because I've had to look into less obvious places trying to diagnose an abrupt nasty/raspy bearing noise that only comes on around that 3600 rpms. I first noticed it once while trying to do an Italian tuneup two years ago, but I had to leave the state and I figured it would be a smaller pulley bearing. The noise persisted after changing the idler/tensioner pulley, and the alternator, and bypassing the AC compressor.

I've also had bad gas mileage and my engine has taken a while to warm up (not the case now).

I changed the fan clutch a bit ago and omg, I had no idea how quiet it would sound at all RPMs, especially from 2000-4000. I'm used to it roaring especially while I'm on the highway, in 4low, and when I drive around with OD off.

I just took it to 4,000 RPMs multiple times and it was boring bc it's so refined/quite lol. The loud noise was all I knew bc I installed the fan clutch to replace the PO's failed e-fan soon after the Jeep purchase. And the awful bearing noise did not happen when hitting 3600, so I took it past 4,000 multiple times and still no noise.

That said, I think this USMW fan clutch might be bad. It has slight play in it...I can slightly wobble the clutch by prying the fan blade, or clutch itself, back and forth. @freedom_in_4low can you feel any slight play in your clutch if you pry back and forth on the fan blade?

In addition to the much quieter ride, I noticed that my IATs were higher than I've seen in the mid-range...since the fan was not pulling as much air through the heat-exchanger that water cools the intercooler.

If I'm not able to get an exchange for the Mopar clutch, would the 2791 or 2771 be better for pulling air through the radiator and heat-exchanger in idle and until the grill takes on higher wind speeds? This is a big deal for making mid-range power in the AZ summer because the PCM pulls timing as IATs increase.

 

[MikeE024]

A clarification: I say "As soon as it drops below that, it will lock up again", but I don't know if that means it will lock at 2500 (to pull a random RPM outta my ass) or hold off til its lower. In my case, I've observed when its unlocked at about 3K, then I come to a stop sign, then its re-locked as I pull away. In other words, I don't have it completely quantified - and in normal driving, I'm not above 3K very often.

Sounds good man I need to make a decision regarding the 2771 vs 2791. Sounds like either one will do the job, and I'm used to the noise at this point. At this point, I care more about which will put less strain on the water pump at higher RPMs. But I also want something that will keep IATs down in the mid-range.

Side note: My ECTs with the USMW stayed in the proper range (bounced between 190 and 205), but I don't know if I'd trust the fan to help enough in extreme AZ summer conditions. I'd trust the USMW in less extreme ambient conditions when the thermostat is working properly.

 

[Zorba]

Sounds good man I need to make a decision regarding the 2771 vs 2791. Sounds like either one will do the job, and I'm used to the noise at this point. At this point, I care more about which will put less strain on the water pump at higher RPMs. But I also want something that will keep IATs down in the mid-range.

I welcome the increased airflow at lower RPMs, but noise doesn't bother me. I notice all the HD trucks driving around here sound pretty much the same - lots of fan roar at low RPMs. I figure what's good for them, is good for me - at least in THIS climate!

 

[MikeE024]

I welcome the increased airflow at lower RPMs, but noise doesn't bother me. I notice all the HD trucks driving around here sound pretty much the same - lots of fan roar at low RPMs. I figure what's good for them, is good for me - at least in THIS climate!

Apparently, I don't mind it either lol. But, I look forward to the fan not roaring at 2500-4000 RPMs during spirited and highway driving.

 

[Zorba]

Apparently, I don't mind it either lol. But, I look forward to the fan not roaring at 2500-4000 RPMs during spirited and highway driving.

Yea - mine has been shutting down at about 3K as I noted earlier, which makes sense. But I'm usually turning around 2300 on the highway if I remember correctly.

 

[MikeE024]

It's not keeping the engine cooler by running when it's not needed, such as when it's not even hot enough to open the thermostat.

This could help improve the AC or help cool additional heat exchangers (e.g., steering/transmission/boost) in the grill...unless I'm mistaken?

 

[MikeE024]

hard to tell how much force you're using to spin it, but mine does not freewheel after I spin it, either (it's sat overnight and the outdoor temperature is 48°F) so I'm not sure you can condemn it based on that.

Between the USMW and two Hayden's (including one that LOOKS just like the Mopar), they all even make audible fan noise when I first start. The difference however, is that the Hayden would ROAR the entire 5/8 mile out of my neighborhood and onto the main road, whereas the USMW quiets down before I hit the end of my 90' driveway.

When I got sick of the Hayden was when I was wheeling at high elevation in Colorado, with temps in the 40-50s, basically engine braking down an easy 3,000' descent for 2 hours, so basically zero engine load. My thermostat had malfunctioned and ECT wasn't even getting to 170 - I could barely hear my GMRS radio over the fan noise. It should not have been engaged at all according to factory specs which call for engagement when air coming off the radiator exceeds 170°F. The USMW seems to behave correctly this way - past the end of my driveway, I don't hear it unless the engine is actually up to temp and I've been at a stop light and the weather is well into the 80s.

Maybe my USMW is bad then because it makes very little noise on start up and I didn't notice it making noise when driving. I pulled over and was able to spin the fan a full turn (the stocker barely moved cold or hot).

 

[MikeE024]

Are you experiencing any sort of temperature problems, or any sort of unusual fan roaring at times when it didn't in the past?

I now know that the Mopar clutch was locked up; especially noticeable when going 3000-4000 RPMS.

Cooling system works well so no cooling issues.

But the fan roared like being behind a Tomcat exhaust in higher RPMs, which may have been the reason for the bad bearing noise that only happened around 3600 RPMs.

The USMW unit is quiet as a mouse (blew my mind last night when I could only hear the turbo and exhaust...sounds refined like a new vehicle lol).

I didn't have anything to previously compare it to bc I ripped out a bad e-fan and went full Mopar for the cooling system after acquiring the rig.

 

[freedom_in_4low]

The reason I looked into the fan clutch is because I've had to look into less obvious places trying to diagnose an abrupt nasty/raspy bearing noise that only comes on around that 3600 rpms. I first noticed it once while trying to do an Italian tuneup two years ago, but I had to leave the state and I figured it would be a smaller pulley bearing. The noise persisted after changing the idler/tensioner pulley, and the alternator, and bypassing the AC compressor.

I've also had bad gas mileage and my engine has taken a while to warm up (not the case now).

I changed the fan clutch a bit ago and omg, I had no idea how quiet it would sound at all RPMs, especially from 2000-4000. I'm used to it roaring especially while I'm on the highway, in 4low, and when I drive around with OD off.

I just took it to 4,000 RPMs multiple times and it was boring bc it's so refined/quite lol. The loud noise was all I knew bc I installed the fan clutch to replace the PO's failed e-fan soon after the Jeep purchase. And the awful bearing noise did not happen when hitting 3600, so I took it past 4,000 multiple times and still no noise.

That said, I think this USMW fan clutch might be bad. It has slight play in it...I can slightly wobble the clutch by prying the fan blade, or clutch itself, back and forth. @freedom_in_4low can you feel any slight play in your clutch if you pry back and forth on the fan blade?

In addition to the much quieter ride, I noticed that my IATs were higher than I've seen in the mid-range...since the fan was not pulling as much air through the heat-exchanger that water cools the intercooler.

If I'm not able to get an exchange for the Mopar clutch, would the 2791 or 2771 be better for pulling air through the radiator and heat-exchanger in idle and until the grill takes on higher wind speeds? This is a big deal for making mid-range power in the AZ summer because the PCM pulls timing as IATs increase.

Is it wobble or is it play in only the thrust direction? Wobble is no good but just in and out would worry me less.

I can flex mine a little bit but I wouldn't characterize it as slop.

 

[freedom_in_4low]

@MikeE024 if you end up wanting a Hayden, I've got a 2771 and a 2791 both in their original boxes that I'm open to parting with. The 2791 was ran about 6k miles in a year, the 2771 was on for a week. PM me if you want one.

 

[MikeE024]

Is it wobble or is it play in only the thrust direction? Wobble is no good but just in and out would worry me less.

I can flex mine a little bit but I wouldn't characterize it as slop.

Glad you asked. I just checked again, and it's not doing it cold.

However, it had play when warmed up this morning that you could feel accompanied by a slight knock sound (with about 1/16" or so of play...enough to widen my eyes a bit).

It did this in all directions e.g., 3 & 9 and 12 & 6 clock positions. I'll probably return this one just to play it safe. I initially thought it was a screw loose even though I torqued them to spec and confirmed the fan was on correctly.

 

[MikeE024]

@MikeE024 if you end up wanting a Hayden, I've got a 2771 and a 2791 both in their original boxes that I'm open to parting with. The 2791 was ran about 6k miles in a year, the 2771 was on for a week. PM me if you want one.

Sounds good man I'll let you know after I find out if the Mopar unit can be exchanged. I think the 2771 or 2791 would work well for my needs since I benefit from more air being pulled through the coolers in the grill.

I'm definitely not paying another $160+ for a Mopar unit. And I'm not sure yet if the water pump is damaged (the locked clutch might have caused the bearing noise to come from the clutch or the water pump bearing). Not making any predictions at this point, just gotta see what happens here in the future.