viscous fan drive

[Bob Bancroft]

I have never trusted these things- because I don't know how you know if they are really working!?
Now I know I don't trust them- I called my friendly CaseIH mechanic and he said fully "engaged" they only run 80-85% of the speed of the drive!
My tractor has run right to the very top of the green, right on the edge of the red, and it's not been all that hot here.
Anybody have any ideas/experience on dealing with these?

 

[fixerupper]

Don't know about CIH but Deere has a lockup kit for some models, but I don't know how many models it covers. It consists of two straps and a couple of bolts that lock the hub to the fan. Just put them on the 4650 and the dealer was sold out of them after our 97 degree day the other day. Jim

 

[rexhellwig]

Yes.

Can you be more specific about the details?

 

[Bob Bancroft]

Like what? Ask me some questions.

 

[Bob Bancroft]

So apparently locking it up will make a difference?

 

[fixerupper]

I forgot to say, I also spent three hours blowing, washing, blowing, etc. out the radiator. Had a pile of mud on the shop floor after I finally got to blowing clear water back out of the rad fins. Whoever had this tractor before me hadn't thoroughly cleaned the rad forever. You can blow with air until you're blue in the face and not get it all if the dirt is hard caked between the cores and fins. Haven't had a chance to run it yet to see if it will run cooler but I'll betcha it will.

 

[fixerupper]

The Deere mechanic said it will make a difference and he sounded pretty confident when he said it. Jim

 

[rexhellwig]

what model?
fueled up?
will it actually getting hot enough to boil the coolant?
radiator, condenser, screens dirty?
radiator ever been rodded?

that's just a beginning

 

[Bob Bancroft]

Thank you.

 

[Bob Bancroft]

CaseIH 7240. My 5th season with this tractor. I have no idea about its prior life, except that it's in very nice shape. I cleaned everything up when I first got it, and keep it that way. Coolant filter is changed every engine oil change. When it got right to the top of the green I backed off to 8th gear(Unverferth 9 shank disc chisel) It still ran fairly hot, and it wasn't all that hot here.

 

[Bob]

Yes, it does. My friend put them on his 4650 last summer and was well satisfied.

<img src = "http://i54.tinypic.com/okwjtd.jpg">

 

[Bob Bancroft]

Which? the lock-up kit, or the IH decal?

 

[johnbobin]

Check the raditor cap pressure.

 

[TravisM]

Our 7230 was running towards the top of the green with our 32 ft field cultivator on it. Took it to the shop washed out and blew out the radiator, problem solved

 

[buickanddeere]

Find out what edge of the green actually means in actual measured temp. If it's 180-195F you are just chasing your tail and worrying about a non issue.
The viscous clutch saves you $$$ in cool weather and at part load.

 

[430WLPG]

I would first replaced the temp sender, Some 7120's didn't have the viscous drive and I have installed those direct drive parts on to a 7140 and the fit, but the trouble they was having was the a/c wouldn't cool. The fan wouldn't pull enough air to let you put in enough freon. They were raking hay at night so they never seen it heat up, cool night air and light load.

 

[Bob]

NO decal. They are IH weights with the "IH" cast in. (Which I brightened up a bit before posting the photo!) And, yes, he put the fan lock-up kit on it.

 

[rexhellwig]

There is nothing fancy about this fan drive.
The radiator fins in front of the drive must be clean so that heat from the radiator can impinge onto the heat sensor on the front of the drive. This will make the drive spin a little faster - IF the fluid hasn't leaked out.

The next time you shut down the engine while it is hot, see if the fan wants to spin for a few seconds longer. If it does, this might mean the fan drive has seen its better days.

With the engine cold, drain down a couple gallons of coolant and remove the upper hose from the radiator. Take a look inside with a good light. Is there white looking junk built up on the tubes restricting flow through the core?

Maybe you're luckier. Maybe the gauge simply isn't reading right.

Before you go modifying this or that, remember: It did not always "run hot".

 

[Bob Bancroft]

I hadn't thought of that and should have. I so didn't trust the idiot light for engine oil pressure I screwed a gauge into the side of block where I just look at it occasionally and it has great oil pressure.

 

[Bob Bancroft]

I don't shut it down until the coolant temp is back down in the middle of the green(5 or 6 bars), and the exhaust temp shows two bars.
Do you think that's still hot enough that the fan should freewheel less than with a cold shutdown?

 

[rexhellwig]

If you're worried about damage from shutting down a hot motor, you can shut it off for the few seconds you need to observe the fan and quickly start the engine back up again.

 

[fixerupper]

Come to think of it, the 4650 rad was plugged the worst in the fan hub area. Jim

 

[rexhellwig]

If Magnums were "underbuilt" anywhere, it's news to me.

By FAR, the majority of these complaints are from:

- False temperature indication from a bad sensor or connection.
- A dirty radiator or condenser exterior.
- A dirty radiator interior.
- A failing fan drive, fan belt, or belt tensioner.

 

[fixerupper]

Did that with the oil press gauge in the 1086 years ago. The circuit board in the dash is funny acting and sometimes the electric oil gauge reads zero till I rap on it. Made a bracket to hold a manual gauge just outside the lower right cab window and plumbed it to the oil galley with a short grease gun hose.

First time the electric gauge read zero while I was plowing in the middle of the night years ago I almost had a heart attack. Jim

 

[Tx Jim]

My JD 4255 has had the fan lock-up kit on it for yrs. It's a common practice to install lock-up kit down here in hot Texas.