M809 fan clutch conversion

[162tcat]

Hey all,

Has anyone converted an M809 series from direct drive fan to an air clutch setup like the M939 series? I know the fans are different from M809 to M939 even though the NHC 250 engine is in both. Fan spacing is tight on the older trucks but it sure would be nice for the engine to warm up quicker and not hear the fan all the time. Might help the power and MPG a little too.

 

[simp5782]

I have everything needed to do the swap. I offered it for sale awhile for a pretty decent price but i never got any bites.

 

[162tcat]

I have everything needed to do the swap. I offered it for sale awhile for a pretty decent price but i never got any bites.

Is it just a replacement for the existing hub that is air actuated? And how much?

 

[simp5782]

It is everything from a 939 series NHC250. you would have to modify the radiator shroud on the 809s and the upper mount that goes to the radiator from the engine. i believe was the case. It was the water pump, water pump backing plate, Fan clutch to upper mount bracket, air actuated fan clutch. i think I had 450 on it shipped.

the Fan clutch is nearly brand new. Along with everything else.

 

[sandcobra164]

One last item you will need is a method for actuation in case the fan is actually needed. I see you're in Washington state so it might not need the fan at all except for in stop and go traffic. That's the only time it comes on in my M923, stop and go traffic in the summer on really hot days. It doesn't even come on idling in the Christmas Parade for an hour or so when the temperature is in the 40's. Running down the road in 95 degree air it never comes on. My shutterstat is working fine as installed from the factory but I'd probably do like Wes did and install a fan switch to control when it comes on in your situation and will likely go that route if my shutterstat ever fails.

 

[Superthermal]

@162tcat did you every do this modification with the fan assembly?

 

[162tcat]

Negative. Too much work for little gain. Swapped to Delco alternator after the military junker died, new water pump gaskets and belts, fresh sca coolant and pedal to the floor. Biggest improvement this truck could use is a tranny with better ratio. I have one big hill out of the gravel pit and do 2-5 in low range then shift to high for 4 and 5.


Sent from my iPhone using Tapatalk

 

[Superthermal]

I was thinking the on demand clutch fan would be nice for deep water crossings and the HP savings. Still interested, but not until a long list is done.

 

[162tcat]

Best upgrades I’ve done to this truck are gear reduction starter, shifter boots, heater, led tail and backup lights.


Sent from my iPhone using Tapatalk