Quick fan clutch question

[BRob2756]

Reading up about the fan clutch problems and replacements. About to order an Ultragauge to monitor my temp. Is the Ultragauge website still the best place to buy these?

Anyhow, stopped the truck today and shut it off. Grabbed the fan and it moved freely in each direction! Truck was at normal operating temp - do I need to check clutch when cold? Does that much easy movement when hot mean the fan clutch is toast?

Thanks!

Rob

 

[blkprj80]

As far as I know, the only place you can buy an Ultragauge is from their website. Be sure to figure out how to add an alarm when the temp hits 200 (or wherever you like). I like that feature.

I'm not sure on your fan clutch. How many times will it spin when you flip it with your hand?

 

[LFD2037]

It's the only place you can buy it. Roll up a news paper & see how easy it is to stop the fan while it's running. BE CAREFUL!

 

[Tools R Us]

... Anyhow, stopped the truck today and shut it off. Grabbed the fan and it moved freely in each direction! Truck was at normal operating temp - do I need to check clutch when cold? Does that much easy movement when hot mean the fan clutch is toast?

Thanks!

Rob

Define "hot" the fan is only needed under some conditions, the rest of the time the clutch releases it, so maybe working as intended. Likely best to get the Ultragauge, then see what you have?

 

[Mighty690]

FWIW, I'd suggest you go to RockAuto and order the Aisin fan clutch. I did this not too long ago and it was the "blue hub" clutch. The ultragauge is would be nice too, but "when in doubt, change the fan clutch out" is my experience.
The only time I've seen my temp gauge move off center (once warmed up) was charging hard up a mountain road in summer with the AC blaring. I was keeping a close eye on the temp and when it moved upwards I pulled off immediately (shutting down the AC of course) knowing the stock gauge only responds to large temp changes. I opened the hood and (protecting my hand) was able to easily stop the fan from spinning. No harm done, fortunately, but I should have changed that fan clutch when I bought the vehicle as baseline maintenance.

 

[BRob2756]

Thanks for the answers. Truck was at operating temp - will try the news paper trick as well.

When cold, I should not be able to spin fan at all - correct?

If fan clutch is toast, should I replace water pump while I'm in there? No problems with cooling system, just trying to get ready for a GA summer. Thanks!

Rob

 

[SUMMIT CRUISERS]

When engine is cold, fan should ROAR for about a minute or two after initial startup. If not, change your fluid or your clutch.

 

[Mighty690]

Thanks for the answers. Truck was at operating temp - will try the news paper trick as well.

When cold, I should not be able to spin fan at all - correct?

If fan clutch is toast, should I replace water pump while I'm in there? No problems with cooling system, just trying to get ready for a GA summer. Thanks!

Rob

When cold: "spin" as in very little drag? That would be bad. But, turn fairly easily by hand? That would be normal. Get a new one...
Water pump? If you don't know its age, and plan to drive out of the range of AAA, I'd baseline that too.
My (bad) fan clutch did roar upon startup, btw.

 

[Onefastrx7turbo]

I did the fluid mod to the clutch and when its cold, the fan ROARS, and I mean it's freakin LOUD for the first minute or so of the engine running. Once the fan clutch disengages its noticeably quieter. So much so that I use the fan disengaging as the signal to start driving.

 

[BRob2756]

Thanks. If replacing the fan clutch with Aisin, should I fluid mod a brand new clutch?

Also, went to order Ultra Gauge and saw three different models and price points. All I'm really concerned with is accurate temp but I guess it would be nice to have other info. Any suggestions on which one I should go with? Want to secured next to my gearshift and TCase lever - any reason to spring for a mount? http://www.ultra-gauge.com/ZC/

Thanks!

-Rob

 

[Tools R Us]

...
When cold, I should not be able to spin fan at all - correct?

When cool, with the likely clutch in that rig, the fan should relatively free wheel. But to have any meaningful clutch discussion, first have to define "clutch", there are several that could be on the rig and they have differing characteristics. If it's original, it will be an Eaton (good clutch) and they don't do the start up roar thing.

If fan clutch is toast, should I replace water pump while I'm in there? No problems with cooling system, just trying to get ready for a GA summer. Thanks!

Rob

The water pumps are very reliable, if it doesn't leak or make noise, I would leave it.

 

[Tools R Us]

...
My (bad) fan clutch did roar upon startup, btw.

If it was original, was an Aisin black hub, the best clutch ever put on the 1FZ, a simple drain and refill would have likely restored it to better than new performance.

 

[BRob2756]

If it was original, was an Aisin black hub, the best clutch ever put on the 1FZ, a simple drain and refill would have likely restored it to better than new performance.

Drain and refill with 3000 cst? Or go heavier duty? 10,000? Thanks!

-Rob

 

[Tools R Us]

.... But to have any meaningful clutch discussion, first have to define "clutch", there are several that could be on the rig and they have differing characteristics. ...

Drain and refill with 3000 cst? Or go heavier duty? 10,000? Thanks!

-Rob

What clutch? A pic of it would help.

 

[Mrtwooooo]

Thanks. If replacing the fan clutch with Aisin, should I fluid mod a brand new clutch?

Also, went to order Ultra Gauge and saw three different models and price points. All I'm really concerned with is accurate temp but I guess it would be nice to have other info. Any suggestions on which one I should go with? Want to secured next to my gearshift and TCase lever - any reason to spring for a mount? http://www.ultra-gauge.com/ZC/

Thanks!

-Rob

I'm in Birmingham, you're in Atlanta so our outside temps during the summer are probably not that far off. My truck was running hotter than normal and it had the original clutch from 1995. I drained the fluid and replaced it with some thicker fluid. Not sure if I did it wrong or what but my temps were the same. Towing my 400 pound sailboat on the trailer (about 800 pounds total) I was sitting at about 205 to 210 cruising down the interstate. I bought a brand new Aisin Blue hub fan clutch off amazon. Didn't modify it at all . Just installed it.. Temps are now right where they should be. I may hit 200 or a tad higher in the summer going up a big hill but other than that everything is normal. All my readings are coming from a Scangauge. I haven't found any reason to mod the fluid in the clutch. Might consider it if I lived somewhere where the temps were well above 100 in the summer.
Hope that helps give you some real world data from someone in the same region

 

[BRob2756]

Tools - Thanks for your help. Believe fan is original OEM from 97. Looks like i am over thinging - I will but the Blue and rebuild the current for a trail spare.

I'm in Birmingham, you're in Atlanta so our outside temps during the summer are probably not that far off. My truck was running hotter than normal and it had the original clutch from 1995. I drained the fluid and replaced it with some thicker fluid. Not sure if I did it wrong or what but my temps were the same. Towing my 400 pound sailboat on the trailer (about 800 pounds total) I was sitting at about 205 to 210 cruising down the interstate. I bought a brand new Aisin Blue hub fan clutch off amazon. Didn't modify it at all . Just installed it.. Temps are now right where they should be. I may hit 200 or a tad higher in the summer going up a big hill but other than that everything is normal. All my readings are coming from a Scangauge. I haven't found any reason to mod the fluid in the clutch. Might consider it if I lived somewhere where the temps were well above 100 in the summer.
Hope that helps give you some real world data from someone in the same region

Mrt - This is perfect, big help. My truck spent most of its life in the Pacific NW - got to get it ready for a 'jungle hot' GA summer! Thansk for the help.

Best,
Rob

 

[LFD2037]

No need to by a blue and have a spare. It's not an item that'll break easily plus your factory one is better than a blue. Put 15K oil in it and be done.

 

[Tools R Us]

Agree on the no need for a trail spare, they last a very long time and give a warning when they die. Also agree on 15K for an Eaton. If it is an Eaton, they require a bit of a different drain method, starting with post #43 here: https://forum.ih8mud.com/threads/summer-desert-temp-readings.400234/page-3

 

[Kernal]

Tools: have you come across either type of original fan clutch with failed hub bearings? I have an original Eaton with ~300,000 miles on it that feels like it may have dry hub bearings (halves apart and drained).

 

[rc51kid]

Sorry to hijack, but i have a quick question for tools. What do you need a picture of to tell what type of clutch it is? I have 94 and would like to change the clutch oil soon when i do the oil pump gasket.
I guess what i am asking is that i would like to identify mine before pulling out of the truck so i can order the right oil.