Fan Clutch

[MyPrevost]

Found that the clutch  fan was not operating on low speed signal, removed fan clutch and will collect new one tomorrow,

When removing the six nuts that secure the fan to clutch hub the stud turns with the nut, its a flat headed stud with no means of holding the stud to prevent turning, i have the fan off now, just wondered if others have encountered the same problem and how they removed fan from clutch unit ?

Been reading up on the test method for the fan clutch,and discovered that my 95 marathon series 60  does not operate fan clutch on the relays/ DDEC 111, it has a thermostatic temp switch in the pipe from thermostat to radiator, applying 24 v to the fan wires will prove fan operation in both operations, this one was not operating in low speed speed, solid lock up in high speed.

Have ordered new thermostatic switch from Prevost as a spare, interested in how others have removed the fan from clutch assy ?

 

 

Alberta Canada 1995 Marathon XL #326

[MyPrevost]

On clutches I have replaced there was a series of bolts that secured the fan to the clutch. I tipped the clutch mount towards the engine (away from the radiator) to make it easier to loosen and remove those bolts. Then I carefully leaned the fan against the radiator and removed 4 bolts holding the clutch assembly to the frame so the clutch could be lifted out.

It has been so long I am sure i am forgetting something, but the principle described is correct.

Jon and Di 2006 Liberty Elegant Lady, 2021
Jeep Grand Cherokee, 1950 Ford
Knoxville, TN

Owner of three Liberty Coaches since 1990

[MyPrevost]

Thats the same principle i have used Jon, however my fan has 6 bolts retaining it to fan hub assy, the bolts are flat headed and appear to be of a taper seat design, they turn when undoing the outer nut, as there is no way to hold the inner end, new studs are available from Prevost i will order them up today if not a stock item,

Prevost have 3 different clutch hub units in stock depending on VIN number, mine is available, going to collect today

What would you say is the average life of the fan clutch units ?

Alberta Canada
1995 Marathon XL #326

[MyPrevost]

Don’t get me started on fan clutch life.

With the exception of my first coach that had radiator shutters instead of a fan clutch I have replaced at least one in each of my other two coaches. My air dryer has a longer life than the fan clutch. My engine coolant has a longer life than my fan clutch. The flies that come in when we open the door live longer.

I’ve had tires last longer.

Based on my two coach experience which is a poor sample size, I bet my average is 100,000 miles.

Jon and Di 2006 Liberty Elegant Lady, 2021
Jeep Grand Cherokee, 1950 Ford
Knoxville, TN

Owner of three Liberty Coaches since 1990

[MyPrevost]

Installed new fan clutch assy today, my old unit has been upgraded at least 6 times according to Prevost so its a survivor, bearings are still good and high speed still locks up

MY original post requesting info was self explanatory on removal of old unit, later fan units have 6 bolts threaded into hub to retain the fan, this old unit has 6 nuts that retain the fan to the hub, the studs are off a taper seat design and cannot be accessed from the rear to prevent from turning,

This required removal of fan and clutch unit together, one off a small tack weld on the back of the taper seats allowed removal of the nuts.

4 mounting studs for fan clutch  to support frame required enlarging to mount the new assy, otherwise all dimensions remain the same.

Rebuild is then as per later units with fan in radiator shroud

Fan Clutch assy controlled by Thermostatic switch in top Radiator pipe from engine to radiator, low speed on at 185 deg, high speed on at 199 deg

DDEC 111 prior to relay activated system

Be interesting to monitor life of this later unit, old one will be going into bay as standby.

[MyPrevost]

Make sure the larger diameter of the new clutch pulley does not make the serpentine belt contact anything on the clutch support.

When my last clutch was replaced the belt rubbed against the clutch support housing, and despite what I was told, Prevost did not issue a service bulletin to describe how some grinding of metal was required to provide belt clearance.

Jon and Di 2006 Liberty Elegant Lady, 2021
Jeep Grand Cherokee, 1950 Ford
Knoxville, TN

Owner of three Liberty Coaches since 1990

[MyPrevost]

Hello Jon – did you change the clutch yourself?  Did you remove  the radiator?  I have not yet found any tips or YouTube videos on how to do it, and I now have to change mine and pretty quickly as have out of state trip coming up in about three weeks.  THANK YOU for any details you can share.

 

“Make sure the larger diameter of the new clutch pulley does not make the serpentine belt contact anything on the clutch support.

When my last clutch was replaced the belt rubbed against the clutch support housing, and despite what I was told, Prevost did not issue a service bulletin to describe how some grinding of metal was required to provide belt clearance.”

 

Jon and Di 2006 Liberty Elegant Lady,

Jeff & Sandy
2007 Liberty H3
Toyota FJ Cruiser Tow
Plus Bella & Essie (Chihuahua & Toy Aussie)
Home is 10 Miles North of Houston Intercontinental Airport

[MyPrevost]

Keep in mind this response relates to X series chassis, and OTR equipped coaches.

I replaced the fan clutch on my 97 myself and the clutch on my 06 was changed by ETLC because it is deeper into the engine area and removing it exceeded my desire to lift it with my arms extended.

Both were replaced with the radiator in place. The procedure is actually fast and simple if you are capable of holding the full weight of the clutch with your arms fully extended. Just thinking about that now makes my back hurt.

Jon and Di 2006 Liberty Elegant Lady, 2021
Jeep Grand Cherokee, 1950 Ford
Knoxville, TN

Owner of three Liberty Coaches since 1990

[MyPrevost]

THANK YOU, Jon

Jeff & Sandy
2007 Liberty H3
Toyota FJ Cruiser Tow
Plus Bella & Essie (Chihuahua & Toy Aussie)
Home is 10 Miles North of Houston Intercontinental Airport

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