Loose rad fan

[Asymair95]

Was changing my coolant and thermostat today in my 97 1078. Decided I better check the cooling fan for looseness because of the horrible stories I’ve heard on here of fans flying into the rad. I turned the main power switch on, tilted the cab, and grabbed the fan. I was able to wiggle the fan about a 1/16” or less. My question is how much movement is too much?

 

[Suprman]

Wiggle in proper motion or pulling the blade forward play? Is anything loose? Some of the blades are sandwiched between 2 metal plates with rubber between them and the blade in the middle.

 

[Coffey1]

Just do your self a favor and take it apart and remove that rubber and bolt fan blade to hub.

 

[Asymair95]

Superman,
It wiggles forward to back, but just a little bit, maybe 1/16”

I did have to tighten some of the Allen bolts around the fan when I first got the truck, they had worked themselves loose. Will check them again, but I really haven’t driven it much since then.

 

[Coffey1]

That rubber will rot out and fan will wobble all over the place and when clutch kicks in it can destroy blade and throw it into radiator.

 

[Suprman]

Yup I’m thinking that should be addressed. The fan blades themselves are pretty stiff so they won’t flex. if the mounting is flexing somewhere its probably not right. And yes on a bad day the fan clutch can decide to toss the blade into your radiator. Seen that happen a few times.

 

[Asymair95]

From what I’ve read, finding a new style clutch is pretty easy. Finding a fan that fits it though is tough. Has anyone found a vendor selling the new style fan yet?

 

[Coffey1]

It's a easy fix to remove rubber and bolt fan to hub. And has been a reliable fix.

We've done several trucks with no failures.

 

[Asymair95]

On mine it seems the whole clutch moves, not just the fan. Would that still be the rubber piece causing that?

 

[Asymair95]

Is number 33 the piece you are talking about?

 

[Coffey1]

33 is a shim 31 is the rubber

 

[coachgeo]

It's a easy fix to remove rubber and bolt fan to hub. And has been a reliable fix.

We've done several trucks with no failures.

does that mean the fan can NOT be turned off when fording water?

 

[Andyrv6av8r]

does that mean the fan can NOT be turned off when fording water?

No it can still be turned off.

 

[Coffey1]

The holes are already there on blade and hub all you need are a good grade of bolts and locknuts.

 

[Asymair95]

Isn’t it bolted on already with Allen head bolts (37) ?

 

[Andyrv6av8r]

Isn’t it bolted on already with Allen head bolts (37) ?

Here is a picture of one that has been modified. The 3/16's bolts you see go into existing holes. The rubber is removed and the inner hub is locked to the fan hub. It works exactly like the newer fan and clutch.

 

[Coffey1]

No the Allen head only bolts the hub
The rubber is the only thing holding the blade due to compression

 

[Asymair95]

Will the number 31 rubber mount slide over the air fitting on the end, or does all that stuff need to come off?

Can I re-use bolt 37 or do I now need shorter bolts because the rubber mount is gone?

 

[Andyrv6av8r]

Will the number 31 rubber mount slide over the air fitting on the end, or does all that stuff need to come off?

Can I re-use bolt 37 or do I now need shorter bolts because the rubber mount is gone?

The rubber comes off with the fan. You can reuse the bolts.

 

[Coffey1]

If the rubber is still completely there! Some or all of it might be gone