Fan Clutch

[jlwelding]

So I been listening to my fan clutch staying locked in for weeks  even when Its cool out and it sounds like a jet trying to take off. So I go get a new one this morning and same thing. I dont get it. My old truck didnt have this issue. My old truck you could hear it when it reached a hot temp it would lock in. I dont think the old clutch did this in the winter I would have noticed.
I stayed on the throttle up to 3k rpm and it still locked in.

[Tractorman]

When you are checking out your new clutch fan, are you checking fan operation without driving the truck?  If so, it would be normal for the fan to be in full lockup on a cold start, or even a warm start.  Normally, driving the truck for several blocks or maybe a mile or so, the fan should unlock.  Can you give more detail on how you are checking the fan operation?

 

- John

[jlwelding]

When I backed out of my shop It idled for 3 min. then I pulled out on the hwy, not much traffic. So I can tell its locked in and I drive 1/2 mile down to the turn around just driving normal and I go about a mile and a half to the road to my house. I then head back up to the shop and its normal temp now and thats when I took it up to 3k in 3rd and 4th and it stayed locked in.

 

I just took it down the road about 4 miles running 80 and it finally unlocked. Pulled down a back road for about a mile, got back on the hwy and its locked in and I hammer on it and its locked 2nd 3rd 4th and turns loose going into 5th at 2800 rpm. The old clutch would never unlock, at least this one finally did. Im looking into this its not right.

[Tractorman]

Well dang!  That shoots that idea.  

 

Another area to possibly look at would be to check if there is any dirt buildup on the front side and center area of the radiator.  This collection of dirt is caused by crankcase vapors from the OEM location of the engine breather.  It is very difficult to gauge how dirty it is.

 

Years ago this occurred on my truck and would cause a minor heating problem on long grades with heavy loads.  I spent several months trying to figure out the problem.  I even installed a new clutch fan and nothing changed.   Once I saw how badly the airflow was restricted (after removing the radiator), I cleaned it thoroughly and re-installed it.  On my first test drive, I noticed the engine fan was much quieter under all operating conditions.  Previously, the restricted air flow causes so much turbulence around the engine fan that the fan was noisy all of the time.  The long period of time needed for the airflow to become restricted occurred so slowly that I never noticed the ever increasing noise of the fan.  Not saying this is your problem, just trying to cover all bases.

 

Might worth giving the fan a second chance by driving the truck for awhile after the engine reaches operating temperature.

 

- John

 

 

 

 

 

[jlwelding]

Yeah, I spent 12 months with this truck in my shop. Its clean but I am looking again in the morning right before the trip to NAPA. I found the old receipt and both of these clutches are Hayden built clutches. From what Im told they are decent replacements. I just drove 70 miles today in triple digit heat and it sounded like a 747 all the way. 

[jlwelding]

Ok fellas it took me a day or so to get around to putting NAPA fan clutch in and its a win. I cant believe how much of a load was on that eng turning a locked up fan. It even shifts smooth again it really is amazing how you can get used to something and not realize it. That was two Hayden fan clutches totally locked up.

[Tractorman]

Good to hear that you won with your decision to replace a defective new clutch fan.  It's a bummer that you should have to do the job twice, but I am glad to hear the engine is running as it should.

 

- John

[Mopar1973Man]

I've used a lot of NAPA parts and installed a few NAPA fan clutches including Thor which is electronic clutch.