Tabs on 2.9L Fan Clutch: Break Off or Leave On

Here is what I think,

1. The tabs may be there to assist in removing the fan mounting nut?
2. I would suggest replacing it.
3. If you don't want to replace it then cut the tabs off and then file or grind smooth. You may run into balancing issues though.
4. The correct answer would be to replace any part that is damaged, without knowing exactly how this mounts its difficult to be 100% sure.

Ditto on "not sure." I considered that but it doesn't explain why some tabs left/found intact. Or what tool to wedge with. Or why wouldn't break off when untorquing, since made to snap off. The clutch removal loaner tool set has wrenches both for untorquing and for backuo sieze. And no instruction anywhere mentions use of tabs for torquing. It's as if they don't really even exist. And their snap off character suggests, removing once any purpose, such as torquing (or removing from package) is accomplished. But what the hey? Or did I mean, hay. Thanks

Oh, I don't think filing needed. See the already broke off tabs; they look made to snap off....like knock-out in electric box.

like knock out in electric box.

Can't tell for sure, but it looks like characters are stamped on the tag. Maybe it's just for identification.

If they serve no obvious function, and don't mate with a feature on the opposing assembly and you haven't noticed any problems, put it back together. I don't see any balance problems. Any wear marks anywhere to indicate that they mated with anything?

Thanks...good photo. And, nothing to indicate any function except packgaging protection in transit to point of sale. What can't be known readily is any effect they might have had in the failure of the pump. But is does seem like that not having them there at all would lighten the load on the clutch itself. If they are not for balance, and made to snap off, then perhaps their only "function" is to be snapped off. Or not:(

But here's another idea. Looking at your photo on the right...seems the tabs could play a role in the mfg process handling. At the same time, leaving some attached would seem to run counter to the admonisment to purchasers to never lay the new clutch flat...lest it be hydraulically ruined. Also, given the absense of two rather than...all tabs, one is left to wonder: Was it just some lazy, disdainful line worker who did not want to be bothered removing more than two tabs. Or is the absence of just two tabs a hint that the others are not needed and should be removed; or conversely. I have contacted AutoZone chat in hopes they might be able to get factory/supplier answer. I'll post their answer if it is forthcoming.

I think you are over analyzing this.

But, you may have a point about protecting the spring thingy.

If it doesn't work, change it.

"If it doesn't work, change it."

Hmm! There's a new and intriguing twist. Reminds me of Mario our former squatter, whose motto for delicate repairs always seemed to be: You don't have a heavy ball peen? Here, let me try.

"Analysis paralysis" it is. Those tabs are there so that the same clutch can serve in multiple engine applications, some where the fan is on the front, others where the fan is on the back, they're just locating/mounting tabs which mate with slots on the fan hub.

From a fan clutch patent: "...According to an embodiment of the invention, it is provided that attachment niches, with which attachment tabs extending inward from the fan flange ring engage, are situated on the front and the back of the fan clutch. The attachment niches on the front are offset in relation to the attachment niches on the back in the circumferential direction, i.e., they are situated in a "staggered" manner. This achieves the advantage that the fan may be mounted and attached to the same clutch from either the front or the back. The mounting and fastening directions are therefore preferably the same..."

They're thin and small relative to the entire spinning mass so they probably don't affect the balance but if you're really worried, snap 'em all off.

Now that's the kind of analysis "lysis" (in the fever sense) I have been waiting for, especially the answer to the implication that "leave 'em or rip 'em." When comes to mechanics NY rocks...except Troy. Definitely definitive. And, I had noticed with bemusement the atypical front rear symmetry of mating cavity; and a peculiar "front" embossment that evoked the question: "front of what?" GArate.

Front of the vehicle. The circular spring is a bimetallic thermostatic element, it senses the temperature of the air coming in from the "front" of the vehicle after it's passed over the radiator. It controls the opening and closing of ports inside the clutch which in turn control the flow of a silicone fluid that forms a temperature and engine speed sensitive system for controlling the fan speed.

Totally automatic but not adjustable/controllable, its use has been has fallen in favor of computer controlled electric radiator fan(s) which are both.

If it ain't broke, don't fix it. As long as the engine is cooling when the vehicle is idling, it must be working. Stop worrying about it.