345 Fan Clutch

[grovelander]

Well, this is my first post and I'm not quite sure how this site works--like I'm not sure how my 1985 345 works either. I've owned it for 3 and 1/2 months and it's been in the shop (2 different ones) for more than 2 months with an overheating problem. The two repair shops have replaced the fan clutch 3 times now--each time claiming that the new one they just installed was defective. Has anyone had this problem? Thanks,
GL

[uncleneal]

My 86 345 was overheating until I discovered that the radiator fins were stopped up with dirt and grease. I pulled the a/c condenser loose to get to the engine radiator so that I could clean it. The crud had collected on the engine radiator between the two units. It was running with only about a third of the radiator clear enough that air would flow thru it.
Also replaced the original fan and clutch with a flex fan, but it made a bit of noise when running.
It went from well over 220 degrees down to 160 or so after I cleaned the radiator.
BTW, its not uncommon to find new, defective fan clutches, especially aftermarket ones.
Neal

[scottanlily]

The fan clutch does not engage if it cannot sense the heat blowing over it thru the radiator ,so Neal is right about making sure your radiator fins and the core itself are clean ,if you core is partially blocked it cannot get rid of the heat .Make sure your getting the big heavy duty fan clutch ,it will be listed in the parts book for motorhomes ,not just a heavy duty pickup .most will engage at 180 to 210 degrees ,some are more sensative ,you'll hear it come on loud and clear .also ,when cold ,starting up your coach ,youll hear the fan
roar loudy for a few minutes idling or driving ,then it will disengage to the
normal engine sound until engine temperatures go up hotter .Make sure your
going with a quality part ,they are not all the same ,try checking out Napa
brands or even carquest auto parts .The beefy unit will be obviouse compared to the standard types .

Scott of scottanlily