T444E fan clutch

[Jay Are]

Hello,

So my 2001 International T444E overheated on her maiden voyage home climbing a steep grade.

Once I got over the mountain on a fairly flat road I noticed the temperature starting to climb again. Right as I was looking for a place to pull over I heard a my fan kick in (low rumble sound) and the temperature went down almost immediately and it stayed that way for the rest of the journey home(about another 1.5 hours at mostly 60 mph) I dont recall hearing the fan when I was going up the mountain when it overheated.

Ive watched a ton of fan clutch videos and read what I can find and all the examples of viscous fan clutches I come across have a bi metal thermostat type device on the front that can be adjusted. My clutch doesnt have this and it doesn't look like it ever did. Its kinda hard to see in there though even with flashlight and mirror so I'm not sure if it's been taken off or fell off or mine isn't that kind of fan clutch. Any insights would be appreciated.

I went to a local parts store and they didnt have a listing for a fan clutch for my model of bus that they offer that I could look at. But it was autozone they may not carry most things for a bus I realize now.

Also total noob question but when I'm referencing my engine do I say it's a 2001 T444E? Or a 2001 International? Or a 7.3l turbodiesel? Or all of that?

Thanks in advance

[Mountain Gnome]

Try NAPA. A.Z. doesn't do heavy vehicles



Ask THEM how to define your bus.


Generally, it would be a 2001 International with a 7.3L T444E

[Jay Are]

Thanks I'll give Napa a shot.

[Drew Bru]

Man, I was hoping CadillacKid would answer your post. This seems right up his alley. Welp, maybe he or someone who has an answer will see this now.

[cadillackid]

the fan clutch on these.. before i went to the Horton clutch I installed a Kit-masters CLutch.. (I can find the part number for it if you need it).. that clutch is a borg-warner unit and has the adjustable sensor..



there 3 issue with viscous clutches ive noticed..


1. the IH split radiator means that you rarely get all hot air into the fan clutch.. these clutches operate on the temperature of the AIR coming from the radiator and not the water in it.. the fact half of it is boiling hot and the other half is just warm makes for a hard time to heat up the clutch to engage.. I have a youtube video on how to set thee down..



2. ive found viscous clutches at High RPM dont like to engage until you lower the RPM a bit.. im not sure why just somethiung ive noticed is if your engine is maxxed out around 2400-2600 RPM then the fan wont turn on until the RPM drops a bit.. then it will engage and stay on as long as needed.. perhaps a centrifugal force thing inside the clutch,, so if you have an AT545 climbing a hill at max RPM.. let off the pedal a bit to slow the engine down and if the clutch is good the fan will probably spin up abd you can go back to high RPM..



3. also make sure your radiator fins are clear of debris.. dirty radiator fins will all but block the heat from making it to the fan clutch and it wont turn on..


on another note when I swapped to the Horton E450 electric fan clutch all my cooling issues went away.... im sure the tranny swap helped too.. but that bus never gets hot and I can haul ass up the hills in it now (motor is pumped up)....


-Christopher

[Drew Bru]

Originally Posted by cadillackid

2. ive found viscous clutches at High RPM dont like to engage until you lower the RPM a bit.. im not sure why just somethiung ive noticed is if your engine is maxxed out around 2400-2600 RPM then the fan wont turn on until the RPM drops a bit.. then it will engage and stay on as long as needed.. perhaps a centrifugal force thing inside the clutch,, so if you have an AT545 climbing a hill at max RPM.. let off the pedal a bit to slow the engine down and if the clutch is good the fan will probably spin up abd you can go back to high RPM..
-Christopher

Whoa, this sure is a nice tidbit of information. I've been wondering whether it's my fan clutch, or my hearing, that's crapping out. I pretty much always run it at max RPM (2600 @ ~67mph). I'll have to dial it back a little and see if the fan kicks on when the temp starts creeping up to the 210 range on the dash.

[cadillackid]

Originally Posted by Drew Bru

Whoa, this sure is a nice tidbit of information. I've been wondering whether it's my fan clutch, or my hearing, that's crapping out. I pretty much always run it at max RPM (2600 @ ~67mph). I'll have to dial it back a little and see if the fan kicks on when the temp starts creeping up to the 210 range on the dash.

I started figuring this out when I had a 545.. id be maxxed out and the temp was headed on up.. then if I let off the pedal for even 2 or 3 seconds when i nailed it again my fan popped right ontoi high speed and ran till the temp dropped back then shut off like it was supposed to...



My DEV bus has a bigger fan pulley.. the ratio is such that its water pump spins slower and the borg-warner clutch on it will engage on its own unless I flat out run that bus at 2800 RPM redline.. then it takes darn forever before the fan finally engages.. normally ill get fan around 195-200 but when maxxed out it goes closer to 210 on that bus... and then it runs till it goes down to just above 180 (yes I have that clutch set cold).. and shuts off... normally I drive that bus around 2500 RPM and it rarely even sees 195 unless im climbing.. as I believe at that engine RPM the fan is slowly progressing engagement like they are supposed to and never needs full speed..



the T444E has a smaller fan pulley in relation to the engine pulley so it seems to be affected more.. I think the 466E with serp belts has the smaller water pump pulley as well..

[Jay Are]

Originally Posted by cadillackid

the fan clutch on these.. before i went to the Horton clutch I installed a Kit-masters CLutch.. (I can find the part number for it if you need it).. that clutch is a borg-warner unit and has the adjustable sensor..



there 3 issue with viscous clutches ive noticed..


1. the IH split radiator means that you rarely get all hot air into the fan clutch.. these clutches operate on the temperature of the AIR coming from the radiator and not the water in it.. the fact half of it is boiling hot and the other half is just warm makes for a hard time to heat up the clutch to engage.. I have a youtube video on how to set thee down..



2. ive found viscous clutches at High RPM dont like to engage until you lower the RPM a bit.. im not sure why just somethiung ive noticed is if your engine is maxxed out around 2400-2600 RPM then the fan wont turn on until the RPM drops a bit.. then it will engage and stay on as long as needed.. perhaps a centrifugal force thing inside the clutch,, so if you have an AT545 climbing a hill at max RPM.. let off the pedal a bit to slow the engine down and if the clutch is good the fan will probably spin up abd you can go back to high RPM..



3. also make sure your radiator fins are clear of debris.. dirty radiator fins will all but block the heat from making it to the fan clutch and it wont turn on..


on another note when I swapped to the Horton E450 electric fan clutch all my cooling issues went away.... im sure the tranny swap helped too.. but that bus never gets hot and I can haul ass up the hills in it now (motor is pumped up)....


-Christopher

Schools in session!! Thanks Christopher!! I'll do the uphill test once I get it back on the road.

[BamaBus]

Originally Posted by Jay Are

Hello,

So my 2001 International T444E overheated on her maiden voyage home climbing a steep grade.

Once I got over the mountain on a fairly flat road I noticed the temperature starting to climb again. Right as I was looking for a place to pull over I heard a my fan kick in (low rumble sound) and the temperature went down almost immediately and it stayed that way for the rest of the journey home(about another 1.5 hours at mostly 60 mph) I dont recall hearing the fan when I was going up the mountain when it overheated.

Ive watched a ton of fan clutch videos and read what I can find and all the examples of viscous fan clutches I come across have a bi metal thermostat type device on the front that can be adjusted. My clutch doesnt have this and it doesn't look like it ever did. Its kinda hard to see in there though even with flashlight and mirror so I'm not sure if it's been taken off or fell off or mine isn't that kind of fan clutch. Any insights would be appreciated.

I went to a local parts store and they didnt have a listing for a fan clutch for my model of bus that they offer that I could look at. But it was autozone they may not carry most things for a bus I realize now.

Also total noob question but when I'm referencing my engine do I say it's a 2001 T444E? Or a 2001 International? Or a 7.3l turbodiesel? Or all of that?

Thanks in advance

What ck says. Today I'm putting a new radiator back in. I am also replacing the fan clutch.

It was like this with the bi-metal cover (shown removed)



and replaced with this


The only thing I remember buying from local parts stores are some batteries and just got some coolant from NAPA. No one had what I wanted in stock and only NAPA offered to get it. The above fan clutch came from Fan Clutch Masters at a good price. I have bought a lot from RockAuto.

Which transmission do you have?

[Jay Are]

Originally Posted by BamaBus

What ck says. Today I'm putting a new radiator back in. I am also replacing the fan clutch.



It was like this with the bi-metal cover (shown removed)



Attachment 46749



and replaced with this

Attachment 46750



The only thing I remember buying from local parts stores are some batteries and just got some coolant from NAPA. No one had what I wanted in stock and only NAPA offered to get it. The above fan clutch came from Fan Clutch Masters at a good price. I have bought a lot from RockAuto.



Which transmission do you have?

Yeah mine's like the first picture, and I guess the cap is still on mine after seeing it with the cap thing off. Right on I'll try rock auto when I get the chance to do it.

I know it's Allison something and was rebuilt just before it was taken out of service. Other than that though I dont know I havent had a chance to get under it.

[coolcraftnet18]

The AT545 makes a lot of heat

[daytripper2]

Originally Posted by cadillackid

the fan clutch on these.. before i went to the Horton clutch I installed a Kit-masters CLutch.. (I can find the part number for it if you need it).. that clutch is a borg-warner unit and has the adjustable sensor..



there 3 issue with viscous clutches ive noticed..


1. the IH split radiator means that you rarely get all hot air into the fan clutch.. these clutches operate on the temperature of the AIR coming from the radiator and not the water in it.. the fact half of it is boiling hot and the other half is just warm makes for a hard time to heat up the clutch to engage.. I have a youtube video on how to set thee down..



2. ive found viscous clutches at High RPM dont like to engage until you lower the RPM a bit.. im not sure why just somethiung ive noticed is if your engine is maxxed out around 2400-2600 RPM then the fan wont turn on until the RPM drops a bit.. then it will engage and stay on as long as needed.. perhaps a centrifugal force thing inside the clutch,, so if you have an AT545 climbing a hill at max RPM.. let off the pedal a bit to slow the engine down and if the clutch is good the fan will probably spin up abd you can go back to high RPM..



3. also make sure your radiator fins are clear of debris.. dirty radiator fins will all but block the heat from making it to the fan clutch and it wont turn on..


on another note when I swapped to the Horton E450 electric fan clutch all my cooling issues went away.... im sure the tranny swap helped too.. but that bus never gets hot and I can haul ass up the hills in it now (motor is pumped up)....


-Christopher

hey thanks for all the useful info...
We have a 2003 t444e that overheats sometimes. We had the fan clutch replaced but it is a viscous clutch and although it engages eventually, it is a bit finicky as you've explained and leads to temps getting too hot.
I also just saw your video about how to adjust the spring on these viscous clutches. We might do that, but have been seriously considering just upgrading to an electric clutch.
Can you explain how you installed the electric clutch? Where does it plug into? how did you power yours? is there something on the engine that can control an electric fan clutch, or would we have to install an external switch or something?

thanks

[cadillackid]

Originally Posted by daytripper2

hey thanks for all the useful info...
We have a 2003 t444e that overheats sometimes. We had the fan clutch replaced but it is a viscous clutch and although it engages eventually, it is a bit finicky as you've explained and leads to temps getting too hot.
I also just saw your video about how to adjust the spring on these viscous clutches. We might do that, but have been seriously considering just upgrading to an electric clutch.
Can you explain how you installed the electric clutch? Where does it plug into? how did you power yours? is there something on the engine that can control an electric fan clutch, or would we have to install an external switch or something?

thanks

you are prob the one I answered on youtube



so in 2003 the ECM is capable of controlling it, but like the viscous they like to let it get really warm before it kicks in unless you have the navistar software to change the ECM program.. I chose to go a different route.
near the thermostat housing on my engine was an 1/8" NPT pipe plug so I installed a Dakota Digital electric fan controller which allows me to set the on / off temps.. and screwed a separate sensor into that spot on the engine. the clutch has a strap for the wire that you tie to any accessory bracket just to keep the wire from spinning... I think I tied mine to my AIr-Conditioner bracket..



I did this 7 years ago so the fan controller i used is discontinued but they replaced it with a nicer one.. that you can program from your phone with an app..



https://www.dakotadigital.com/index....od/prd1207.htm


this also allowed me to wire a hot wire t oa dash switch and into the 'A/C+' terminal which calls for the fan all the time so you can run your fan continuous if you know you are going to climb a long hill or such and want extra cooling.



this is I believe the clutch kit I used. (when i got mine is about 1/4 the cost!).


https://www.ebay.com/itm/296446009543




I need to dig up my old thread on here of when I installed this and how i did it..

[cadillackid]

OK im trying this.. this is part of a thread where i did the retro fit..


wow this is even before i did the tranny swap.. i still had the crappy AT545..



https://www.skoolie.net/forums/f18/g...-15124-10.html

[daytripper2]

Originally Posted by cadillackid

you are prob the one I answered on youtube



so in 2003 the ECM is capable of controlling it, but like the viscous they like to let it get really warm before it kicks in unless you have the navistar software to change the ECM program.. I chose to go a different route.
near the thermostat housing on my engine was an 1/8" NPT pipe plug so I installed a Dakota Digital electric fan controller which allows me to set the on / off temps.. and screwed a separate sensor into that spot on the engine. the clutch has a strap for the wire that you tie to any accessory bracket just to keep the wire from spinning... I think I tied mine to my AIr-Conditioner bracket..



I did this 7 years ago so the fan controller i used is discontinued but they replaced it with a nicer one.. that you can program from your phone with an app..



https://www.dakotadigital.com/index....od/prd1207.htm


this also allowed me to wire a hot wire t oa dash switch and into the 'A/C+' terminal which calls for the fan all the time so you can run your fan continuous if you know you are going to climb a long hill or such and want extra cooling.



this is I believe the clutch kit I used. (when i got mine is about 1/4 the cost!).


https://www.ebay.com/itm/296446009543




I need to dig up my old thread on here of when I installed this and how i did it..

hey yeah haha, you replied to my gf with a similar question on youtube. Thanks for the super quick responses!
Man it would be ideal to have the ECM control it, but no we dont have the software... Then again, being able to switch the fan on/off when you want sounds even better...

I looked for the 1/8th plug you mentioned where the sensor would go. I found this larger plug on mine right above the coolant filter.

according to the manual its a 3/4. There should also be an extra 3/8 available to use but i don't see it.

Anyways, we're seriously considering this install. Were just not that confident when it comes to wiring and electronics, plus we just bought this brand new viscous clutch so it feels like a waste. Do you think adjusting the spring on it 10degrees should be good enough? how would you say that compares to just having the electrically controlled one?

appreciate all the knowledge
P.S. happy 4th

- Serge & Alex (FT.Lauderdale)

[BamaBus]

Originally Posted by daytripper2

...We have a 2003 t444e that overheats sometimes. We had the fan clutch replaced but it is a viscous clutch and although it engages eventually, it is a bit finicky as you've explained and leads to temps getting too hot...

Don't overlook item 3 in cadillackid's response concerning the radiator.
I have a 2002 t444e short HC bus with a reman engine. The tube that routes the blow-by was positioned to blow vapors under the bus toward the front. I suspect that since it often idled, that the vapors circulated to the front only to be drawn back through the radiator. The radiator and intercooler were clogged with oil/dirt! It took a lot to clean it out.

[cadillackid]

3/8.. ..thats it.. thats the one i used on mine because my sensor sticks up and not out.. my bus has an A/C above the water pump and there is a Bendix air compressor on the driver side so it was tricky to gret to that plug but I had the whole front of the bus torn off when I was doing that... had my radiator steamed too...

[cadillackid]

I should mention.. sort of in response to your youtube reply that havign a switch alone for your electric fan clutch is a dangerous proposition.. as if you forget to turn it on then you will over heat.. so you want a controller of some sort.. I chose the dakota digital so I could easily change the temperature range on the fly vs havign to go through the Navistar software each time..

[nikitis]

I still have the crappy AT545, but the only time my T444E has overheated was climbing a 900ft straight up mountain climb. I kind of expected that.

Barring that, i've had no issues, so I guess mine is just working. Next time I try the mountain climb I'll let off the RPM's to see if it kicks on. I have an older T444E though from 1994.

[daytripper2]

Originally Posted by cadillackid

I should mention.. sort of in response to your youtube reply that havign a switch alone for your electric fan clutch is a dangerous proposition.. as if you forget to turn it on then you will over heat.. so you want a controller of some sort.. I chose the dakota digital so I could easily change the temperature range on the fly vs havign to go through the Navistar software each time..

Alright we went ahead and bought the EC450 and dakota controlle thanks for pointing us in the right direction.

I have one more question though, how did you wire the dash switch?

In the diagram below i get that we want a switch in place of where the A/C+ would go. But Im not sure what that would look like. Are we just giving it a continuous 12V from battery to tell the controller to engage the clutch, and then switch off takes away the 12V?




Thanks again!

P.S. in response to the radiator comment- do you have to remove the radiator to clean it thoroughly, or will poking out the dirt & debris be enough?