1983 35FC 3208 Engine Fan Rebuild/Replacement [Facet Fan]

[gregoryoconnor]

I bet the belts and bearings take quite a jolt when the fan clicks on at 2800
rpm. In my old 3208's I would switch the fan on at a lower rpm in fear of an
automatic come-on when the r's are at top spinn. The problem with switching on
the fan prior to a climb or stress is the fan is a stress added to the engine.
Use of fan robs 35 hp from the power that was available to torque the rear.
:when you climb with the fan a 250 hp cat leaves you 215 hp for that period most
needed.

It is interesting to note that the fan engaged on a down hill decent will slow
the bus a bit and keep the r's under the lowergear choice with less service
brake use. the down hill power/fuel generated by gravity is eaten up as the fan
uses 35 hp of that power to spinn. Test is easy :if you run no throttle , down
hill, slow, in 2nd gear using engine speed to keep the bus within r's, switch on
the fan and notice that the progression of speed increase cause by gravity
slows. Progression of speed on a down hill is exponential so the little added
stress of the fan use at a lower r could remove the need to use the service
brakes all together during the slow decent. I believe that using my dumptruck
fan as a alternative to use of the illegal jake causes me 1/2 the service life
of the fan.

[when I descend in a commercial Dumptruck on the California highway hills, I run
up to max rpm then get on the service brakes and slow the truck down hard and
brief to the down shift rpm. This heats up the drums quicker but allows them to
cool for use and service during the better part of the decent.]

Another test of stress to run the fan is to drive for 100 miles on a control
environment with and without fan then check the MPG of both instances. I bet it
is better than one mpg cost to run.

I bet another reason these fans appear to fail more often with the Wanderlodge
is ;Owners pressure wash the grease out of the bearings and ;Owner prompted over
use of fan thinking it is necessary to keep the engine cool.

There are fan clutches that work with air pressure. One more common type is a
horton air clutch. On some air clutches the fan is on/engaged by a spring and
disengaged by adding air ,like the parkbrake. Here is a video on the mechanics
of the air clutch
http://www.kit-masters.com/video1.php

I installed one of the two speeds on my dumptruck to correct the high failure
rate I was experiencing because I was over using the fan. I inadvertently lost
the down hill hold back ability of the one speed fan. You cant have it all. I
am now forced to bump on the Jake in residential areas from time to time, "Sorry
officer, the Rich got'ta swim"

Greg of Tim&Greg
94ptca
"Fort Rainbow"


--- In WanderlodgeForum@yahoogroups.com, "gardendoc17" wrote:
>
> Nate,
> Following is a parts list I used to repair my Facet Fan in my 84FC33 I had
issues with throwing belts which I discovered were related to bearings in the
fan and fan pulley that when cold were fine but after getting hot would seize.
At approx. 200 miles the fan belts would break and take additional belts with
them as they came apart. After many sets of belts and lots of headaches on the
road the following were changed.
>
> Following are 5 different bearing assemblies all associated with the engine
belts that I replaced. 1-3 are for the Facet Fan, 4 and 5 are Idler pulleys.
>
> 1 Large double row fan bearing JAF #5006-2RS (cost $15.00) got it from
Applied Industrial Technologies it is a hard to find size.
>
> 2. Inner fan bearing Fafnir # 9106PP (cost $25.40) (my old bearing was a
NTN # 6006LU) ( Gary Miller used Koyo#60062RSC3GXM )
>
> 3. Fan pulley bearings (2) Timken bearing # 09067, Timken Race # 09195 and
Lip Seal -National #471766 (my old seal # was CR 3N2105)
>
> The following are not part of the fan, but I felt could be related to my
problem of throwing belts, since they felt dry and scratchy and not as smooth as
they really should be, so I replaced them also while everything was opened up.
>
> 4. Air conditioner Idler pulley ...#FAFN 10874 (cost $22.00 from applied
tech) ( Gary Miller used Napa #209842 )
>
> 5. Waterpump Idler pulley... (2) MRC # 305SZZ (old bearing numbers SKF
6305-2RS1/Q66HTS1) ( Gary Miller used (2) Koyo #63052RDC3, Cat Plug #4K0149 and
retaining ring #2D 1523 )
>
> (please note: I would use these bearing numbers as points of reference
only...there probably are several different versions of the facet fan. Also
there was some confusion due to the many different bearing manufacturers part
numbers)
>
> Rick Archie
> 85PT40 "Fort R"
> Fort Worth
>