79jasper
Chickenhawk
I was reading how some clutches you can disassemble completely. Talked about a few mods, and changing out the oil.
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rad fan
- Thread starter jwalterus
- Start date
the fans on the 7.3 super duty trucks are nylon. those make some noise.
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jwalterus
Made in America
Soooo..... current update.... and what NOT to try 
Attempt #1: Cheap nylon flex fan, bolted into 1/4" plate welded to a cut off fan clutch nut (balanced on the lathe), bolted into threaded holes with blue locktite.......... the bolts worked their way out....... minor damage, I got lucky on that one
Attempt #2: New nylon flex fan, same setup, bolts through the plate with lock washers and locknuts on the rear, fan disintegrated at the hub, hub still bolted to the plate, no damage but it only lasted 200 miles.......
Attempt #3: Stock fan, same setup, made a spacer to bring it out to proper spacing from a block of wood, ate a water pump in 1000 miles, might work, but I gave up on that because it went from no drips to spraying out the shaft seal hot and running.
Attempt #4: Stock fan, stock fan clutch, I drilled a hole on either side of center, tapped 1/4-28 and put in grease zerks, filled that thing with Mobil Mobilith SCH 1500 synthetic lithium grease (because I use it weekly on underground hoists and always have it), have been topping it up/checking it every 1000 miles, currently on the truck at 8000 miles.
Truck runs up to temp, thermostat opens up, truck drops to 180, climbs back up to 210, back to 180, and repeat.
Not a full time lockup, but it seems to be (relatively) reliable so far, we'll see once it really warms up how she does.
Attempt #1: Cheap nylon flex fan, bolted into 1/4" plate welded to a cut off fan clutch nut (balanced on the lathe), bolted into threaded holes with blue locktite.......... the bolts worked their way out....... minor damage, I got lucky on that one
Attempt #2: New nylon flex fan, same setup, bolts through the plate with lock washers and locknuts on the rear, fan disintegrated at the hub, hub still bolted to the plate, no damage but it only lasted 200 miles.......
Attempt #3: Stock fan, same setup, made a spacer to bring it out to proper spacing from a block of wood, ate a water pump in 1000 miles, might work, but I gave up on that because it went from no drips to spraying out the shaft seal hot and running.
Attempt #4: Stock fan, stock fan clutch, I drilled a hole on either side of center, tapped 1/4-28 and put in grease zerks, filled that thing with Mobil Mobilith SCH 1500 synthetic lithium grease (because I use it weekly on underground hoists and always have it), have been topping it up/checking it every 1000 miles, currently on the truck at 8000 miles.
Truck runs up to temp, thermostat opens up, truck drops to 180, climbs back up to 210, back to 180, and repeat.
Not a full time lockup, but it seems to be (relatively) reliable so far, we'll see once it really warms up how she does.
Macrobb
Full Access Member
My guess is that you've got issues with your thermostat, and that's the real problem.
If you aren't towing? Thermostat should hold it right between 180 and 190. Above or below that indicates a problem.
You can actually run the truck *without* a fan at all doing this. Temps creep up a little when idling at a stop light, but as long as you are driving at all, it'll stay cool.
Light towing at speed, you don't need a fan usually. I've done it. Same deal; no temp issues until I had to do several miles of sub-20MPH hill climbing. Then it started getting warm...
I don't believe I've ever seen my clutch fan lock up. I've never gotten up to 240 either; I've seen 225 once or twice when towing heavy up a long grade(Mind, this is a turbo rig with a bigger-than-stock IP, too... pushing /lots/ more heat through the engine than stock).
If you're having trouble, don't look at the fan. Look first at the cooling system.
If you aren't towing? Thermostat should hold it right between 180 and 190. Above or below that indicates a problem.
You can actually run the truck *without* a fan at all doing this. Temps creep up a little when idling at a stop light, but as long as you are driving at all, it'll stay cool.
Light towing at speed, you don't need a fan usually. I've done it. Same deal; no temp issues until I had to do several miles of sub-20MPH hill climbing. Then it started getting warm...
I don't believe I've ever seen my clutch fan lock up. I've never gotten up to 240 either; I've seen 225 once or twice when towing heavy up a long grade(Mind, this is a turbo rig with a bigger-than-stock IP, too... pushing /lots/ more heat through the engine than stock).
If you're having trouble, don't look at the fan. Look first at the cooling system.
jwalterus
Made in America
The purpose of this isn't because I've had issues with the cooling system not working well enough in stock form, just kind of looking to see if there is a better or different option than adjusting the spring or swapping to an electric fan setup for people who do have overheating issues. Originally I had just planned on trying a nylon flex fan, but since that was a no-go, I thought I'd try something else.
After it's all said and done, I'll be going back to the original fan clutch and fan from my truck, they are sitting on a shelf in the shed waiting for me to get done screwing around.
My day-to-day winter load in my truck weighs in at about 2000 lbs, and I have about 6000 lbs of trailer and scissor lift behind it most weekends.
To me, that's not a heavy load, what people consider "heavy" varies greatly. I still put an IH 3388 on a trailer behind my truck a couple times a year, that's more than the truck likes with a 3.55 rear.
Previously, in the radiator itself my coolant temp always stayed low enough during the winter where I'm able to pop my cap when the engine's up to temp (after a few hours running) without much worrying about it spraying coolant, I did check it once when I did that, it was right around 140* IIRC.
I should mention, I have seen my mileage drop from 14.7/22 to 13/20 while not towing with this setup, so it's definitely not for someone who is working on maximum economy.
After it's all said and done, I'll be going back to the original fan clutch and fan from my truck, they are sitting on a shelf in the shed waiting for me to get done screwing around.
My day-to-day winter load in my truck weighs in at about 2000 lbs, and I have about 6000 lbs of trailer and scissor lift behind it most weekends.
To me, that's not a heavy load, what people consider "heavy" varies greatly. I still put an IH 3388 on a trailer behind my truck a couple times a year, that's more than the truck likes with a 3.55 rear.
Previously, in the radiator itself my coolant temp always stayed low enough during the winter where I'm able to pop my cap when the engine's up to temp (after a few hours running) without much worrying about it spraying coolant, I did check it once when I did that, it was right around 140* IIRC.
I should mention, I have seen my mileage drop from 14.7/22 to 13/20 while not towing with this setup, so it's definitely not for someone who is working on maximum economy.
so did you put the zerk fitting on the clutch part itself to add fluid and make it engage sooner?
I would like to make my fan work better because it doesn't engage soon enough when the temps start to rise.
I would like to make my fan work better because it doesn't engage soon enough when the temps start to rise.
jwalterus
Made in America
Yes, I was trying to explain where I put them, I really should have take a picture, but I didn't.
Effectively, I filled the inside with grease, not a full lockup, but pretty close, it's been cold most of the time though, so we'll have to see how it functions after it gets warmer (60+), the grease might not be stiff enough when it gets warm out, but I'm not driving to the coast just to check.
ok that's what I thought. the clutch I have is fairly new and it will stay on for a while when I just start the truck, I think there supposed to do that.
but I have gotten the temps up to the 230 area and it has never come on. only if I idle for a long period of time in the hot weather it will kick on.
but I have gotten the temps up to the 230 area and it has never come on. only if I idle for a long period of time in the hot weather it will kick on.
