Fan clutch problem?

[JeanneRon]

We've been experiencing a problem when climbing the Cascade pass'.  After a constant steep climb, it feels as though the transmission is slipping into 2nd gear, engine revving, low power, etc.  We assumed this to be a transmission problem & had it checked at the local transmission shop.  They are unable to duplicate the problem & say it seems to run like a champ.  
I noticed in one of the back issues (22-6)a report of similar symptoms caused by fan clutch seizing.  Does anyone know if this can happen only during higher temps, or have any experience with this problem? The fan seems to turn freely when cool.
Also, there is no fan shroud on the vehicle.  Is this available through regular auto parts stores, dealerships, salvage yards? Identifying size or number?  
Jeanne Gage

[Horst]

I'm a bit out of my league in commenting about this - but I seem to remember reading about similar situations in motorhome usenet posts.
When engaged in a long uphill pull, if you're unable to maintain 50+ mph (in  vintage Dodge or Chevy coaches such as ours), you begin to sorely test certain tranny components (torque converter, etc.)  - in other words, sometimes it's better to run at 42mph in second, with higher RPMs and a more advantageous powerband - than to struggle along uphill in "Drive" (3rd) at about 45mph.
Once your trans fluid  gets real hot - all sorts of "bad" things start to happen.
Horst
This may, however, not at all be your problem.

[junebob]

Jeanne & Ron  :rolleyes:It sounds like your transmisson is doing exactly what it's supposed to do.When you press down on the accelerator to maintain a desired speed it will drop a gear and the engine will rev up proportionately.As to your fan clutch speeding up ,thats what its supposed to do when the driving conditions cause more engine heat.Such as climbing mountain grades.A fan shroud is a definite must for proper cooling. Your best bet to locate one would be a wrecking yard, particularly one specializing in Mopars[Dodge]Any 3/4 or 1-Ton dodge van with a 440 engine would have the proper shroud.There are such Wrecking yards listed on our website,Wildcat Mopar and others.
A Clipper Driving Tip-When climbing a grade ,Instead of just pushing the pedal to the metal and depending on the carburator to drop into 4 barrel operation [Identified by a roaring sound from the engine and clouds of black-gas - smoke rolling out the exhaust]And depending on the transmission to shift down automatically in desperation, trying to meet your demands to maintain 55mph+, which your rig probably can't do,Unless your trying to trash it.Instead maintain your level ground 55 mph throttle setting and rpm.Figuring you have a tachometer, when your rpms[engine speed drop to about 2800 rpm manually shift your transmission into 2nd bring you rpms back up to 3000+ which, depending on how much you go over 3000rpms will climb most hills at 40mph to 50mph, your engine will be working , but not trying to self destruct, you will run cooler, and you will get better gas
mileage. You should get there in the same amount of time with out abusing your old Clipper.Although this method of running "On the pipe"[never lugging or overspeeding]Applies to all vehicles ,new or old,This is incidentley the basic procedure that the diesel big rigs use.    Happy clippering Bob Chaney #2626

[HPotter]

Regarding fan clutch problems, both my brother and I have had clutches lock up while running at high temperatures. When this happens, the added horsepower required to drive the fan at full speed puts enough additional load on the engine that it may well appear that the transmission has shifted down. It also puts a severe load on the drive belt. We replaced our last year when it was causing the drive belt to squeal. Carquest sells two versions for the 440 engine; we got the "heavy duty" model and we find it a bit noisy at city speeds, altho it quiets down after 40 mph or so. This one is a little stiff to turn even with a cold engine. From your description, it sounds like yours is due for replacement.
Harold, #886

[JeanneRon]

I wanted to thank you all for the feedback.  We put on a new fan clutch & for good measure,the largest transmission cooler we could mount (required a little "modification" of the grille to accommodate).  We went over Snoqualmie Pass this last weekend & didn't experience any of the slipping/revving problem as before.  I'll count this one as a win on the motorhoming learning curve.
Jeanne Gage