Size of the Nut That Holds Fan Clutch On? Torque Sets on Tensioner & Idler Pulley???

[rangerenthiusiast]

Size of the Nut That Holds Fan Clutch On? Torque Sets on Tensioner & Idler Pulley???

Hey, all.

In a real jam for time. Trying to replace the broken fan blade on my ’92 Ranger 4.0. Picked up the tool set for undoing the nut that holds the fan clutch on at my local Advance through their loan-a-tool program. They gave a set (I think it was Set 34), but none of the wrenches inside fit the nut on my engine. One wrench has a 34mm on one end and a 1 9/16” opening on the other, but both are just a little too big. Tried using it anyway since I’m in a rush, and it slipped, boogering some of the castellations on the nut, which seems to be on balls tight. Does anyone know what size this damn thing is?? Or if there’s a nut removal tool set that contains it??

I’m also changing out the drive belt tensioner and idler pulley, but can’t find the torque settings for the bolts anywhere in my Haynes manual.

Super frustrated right now. Any help is much appreciated.

 

[Curious Hound]

Sorry I don't have the answer. But...

Maybe You could take a piece of notebook paper, place the paper over the end of the nut and then fold it over the sides of the nut so that it creases the paper. Then measure across the creases on the paper to see what size wrench you need.

Also, check around and make sure the nut isn't reverse threaded. I usually find it difficult to remove a nut that I am tightening by mistake.

Sent from my SM-G960U using Tapatalk

 

[Curious Hound]

Also, if torque specs aren't called out, you can usually default to standard torque for that size and grade of fastener. There are fastener torque spec tables on the internet.

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[rangerenthiusiast]

Sorry I don't have the answer. But...

Maybe You could take a piece of notebook paper, place the paper over the end of the nut and then fold it over the sides of the nut so that it creases the paper. Then measure across the creases on the paper to see what size wrench you need.

Also, check around and make sure the nut isn't reverse threaded. I usually find it difficult to remove a nut that I am tightening by mistake.

Sent from my SM-G960U using Tapatalk

Hey, ericphoto.

Definitely not left hand threads. Ford switched to right hand for the 4.0 in ’91.

 

[rangerenthiusiast]

ANYONE on the torque settings? This is so f@cking annoying and I’m worried about crushing the idler pulley. I’ve been through the Haynes manual over and over again, and watched a dozen sh@tty videos on Youtube. Can’t believe that no one knows this information....

 

[rangerenthiusiast]

Also, if torque specs aren't called out, you can usually default to standard torque for that size and grade of fastener. There are fastener torque spec tables on the internet.

Sent from my SM-G960U using Tapatalk

No idea how to find them...

 

[adsm08]

The fan nut is 36 mm. The torque spec on the tensioner and idler pullies is "tight enough". These are not torque critical fasteners. You will snap off the bolt or the boss before you damage the bearing in the pulley. If you are really worried about it turn the pulley back and forth by hand while tightening. This will prevent binding and let you feel if something changes.

You may have to replace the water pump. I had the fan clutch fail on my one 4.0 and that nut was on tight. I had the right size wrench, the correct holder on the pulley bolts, and she just kept rounding off. I had to pull the whole water pump and fan assembly off and replace the fan blade, clutch, pulley and water pump all as one. It wasn't fun, but with a 6 inch extension it was doable.

And you are correct, the fan clutch is RH thread.

 

[Curious Hound]

I just offered that bit about left-hand threads "just in case". It's easy when the threads are normal.

As Adsm08 said, the tensioner and idler pulleys just need to be tight. You are tightening the bolt to a hardened steel tube (the inner bearing race) and you would strip the threads or break the bolt before you crush that bearing race.

FYI, one place to find torque spec's if you want them is HERE.

 

[rangerenthiusiast]

The fan nut is 36 mm. The torque spec on the tensioner and idler pullies is "tight enough". These are not torque critical fasteners. You will snap off the bolt or the boss before you damage the bearing in the pulley. If you are really worried about it turn the pulley back and forth by hand while tightening. This will prevent binding and let you feel if something changes.

You may have to replace the water pump. I had the fan clutch fail on my one 4.0 and that nut was on tight. I had the right size wrench, the correct holder on the pulley bolts, and she just kept rounding off. I had to pull the whole water pump and fan assembly off and replace the fan blade, clutch, pulley and water pump all as one. It wasn't fun, but with a 6 inch extension it was doable.

And you are correct, the fan clutch is RH thread.

Hmm. Yeah, the tool set they loaned me had a wrench with a 36mm end and it was close, but the little bit of slop it had (along with the narrow profile) just kept causing it to slip off and round the castellations, as you described. Wish I could put some heat to it, but I’m sure it would just melt a bunch of o-rings inside the water pump. Sigh.

I bought a $30 (!) adjustable wrench at work last night, along with a $20 set of strap wrenches to try on it. At this point, I’m thinking about just returning them, putting the old broken shroud back in and running the cracked and chipped fan blade a little longer, since I need the truck tomorrow.

Thanks a lot for giving me a second option with the water pump. It’s probably what I’ll do. Eventually.

 

[rangerenthiusiast]

I just offered that bit about left-hand threads "just in case". It's easy when the threads are normal.

As Adsm08 said, the tensioner and idler pulleys just need to be tight. You are tightening the bolt to a hardened steel tube (the inner bearing race) and you would strip the threads or break the bolt before you crush that bearing race.

FYI, one place to find torque spec's if you want them is HERE.

Thanks, man. And sorry if I sound dickish in this thread, guys. Just really stressed and in a LOT of physical pain. I appreciate everyone’s help on here; the site is practically indispensable to me at the moment.

 

[Curious Hound]

Thanks, man. And sorry if I sound dickish in this thread, guys.

You'll have to try a lot harder to hurt my feelings. I've worked military, construction and industrial maintenance for many years. I just offer whatever knowledge I have. What everyone else does with it is their business.

 

[lvwill]

A little trick I've used over the years on those locked up fan clutch nuts is to hit it with an air hammer a couple times and usually they come right off.

 

[adsm08]

A little trick I've used over the years on those locked up fan clutch nuts is to hit it with an air hammer a couple times and usually they come right off.

Usually.

I actually have the tool that goes in the air hammer for fan clutches. Even that wouldn't take my stuck one off.

 

[rangerenthiusiast]

Usually.

I actually have the tool that goes in the air hammer for fan clutches. Even that wouldn't take my stuck one off.

I’m curious. Is there a name for that tool that I could look up on a tools/parts website somewhere?

 

[adsm08]

I’m curious. Is there a name for that tool that I could look up on a tools/parts website somewhere?

It's called a pneumatic fan clutch wrench set. Lisle 43300.