Rd Fan Drive

[6368]

I have a 96 rd with e7 350 mechanical. the original fan drive lasted 9 years. When i replaced it the dealer gives me a horton relacement . it quits working in less than a year. So get another one which goes bad in two months. I have been driving all winter with a bad drive and its ok, but the first warm day i can't push over 15 pounds of boost on a grade without cooking it. I was told by another o/o that there are different drives that come on at different temps but my local parts dept is of no help. i have also been wondering if there is a air clutch fan drive for this combination. The one on my truck is viscous type. Thanks

[Maxville Truck]

Is your radiator clean? I have several mr's with viscous clutches, they were all low speed engines that I cranked the rpms up on..... once I did that i could not keep belts on them untill I changed the water pump pulleys to the larger diameter.....when my radiator get dirty the fans will roar for a little bit then quit working.... what I suspect happens is that the air flow through the radiator stops and the fan draws cooler air from "lord knows where" and shuts the fans down...

to answer your question "i have also been wondering if there is a air clutch fan drive for this combination. " yes from a ch of the same year the air clutch looks just like the viscous except it has an air hose that will need to be plumbed to a solenoid valve which will need to hooked to a thermostatic switch in the water manifold. I believe that the computer on the electronic engines control the solenoid.... but i'm not 100% sure. you will have to control yours with the thermostatic switch, perhaps from a cummins engine.

try cleaning the radiator first though, if you haven't already especially between the air to air and radiator!!

[6368]

i had the same thought . I tried cleaning the radiator . in fact last time i took the whole thing out and washed it thoroughly and even took the top tank off to make sure the tubes were ok . It didn't drop the temp so thats when i put the second fan drive on. The second drive did drop the temp but i quit hearing it come on after only 2 months. i do hose out my radiator when i wash the truck.

[theakerstwo]

To clean out a rad. that has alot of dirt and bugs the best way is give up and take the air/air off were you can soak with soap and water and then get a hi pressure air hose and blow gun and blow out then look thru with a light and you can see if clean then put a screen over the front to keep some out. The clutch like you have is hard to test and i have seen many of them blamed for heat problems. i test them like the manual calls for and that takes time and i can tell you that the man that can walk up there and tell you that it is bad with out testing is not up to date. If it does not roar when it is hot does not mean that the clutch is bad. The rad. could be restricted or the water pump belt could be slippng and not have much water pump pressure and moving much water and if the rad is stopped up with bugs then you cant blow the hot air out of the rad onto the sensor in the fan clutch. many things act like a bad clutch. To test you have to cover rad with cardboad and cut a small hole in front of clutch sensor and run untill it is turning the fan about 80% of the fan speed which should be max speed and you need a photo tackometer to test with. At that speed your water temp should not be say more than 205 and i ant looking at a manual but you get the ideal now. It will heat real fast now so pull the cardboad out and let cool but this is testing when the fan turns its max speed at what temp.If it dont turn more than say 70% then the clutch is bad or belts are hard or bad or pulleys may be worn out.

[6368]

Here's an update. i went to a different dealer and bought the original fan clutch that came on my truck from new. It works much better. and only cost 3 dollars more than the horton one my local dealer sold me.