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vail426

vail426

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Some one had posted here a short while ago about duramax fan options, the fan clutches, 6 bolt fan, 4 bolt fan and the ways you could wiggle them together. For the life of me, I can't find it. Maybe it was at the other place? Anybody remember? Thanks...
 
I dont think so... I remember reading a thread about matching up bolt holes with other holes on a 1995. somewhere... maybe the other place?
 
This is what my automotive professor recommends against. Showing a poor repair off even as a learning tool because people will do this on their own vehicles. The 6 bolt fan clutch is garbage. Get rid of it and the wimpy fan it has. But you need to replace both to do it right. Just imagine the damage the Duramax fan would do if it came off center on a 6 bolt clutch.

Fan shroud, radiator, belt, clutch, any hose in line with the shrapnel grenade formally known as a fan, and water pump. Maybe dent the hell out of the hood. If the hood is open, well they ban this: clutch fans and no hoods at the track due to heads separated from bodies.

Do the job right : use a 6 bolt clutch with a 6 bolt fan or any 4 bolt fan with a 4 bolt clutch. To do otherwise is risking property damage and your neck with an open hood and engine running.
 
WarWagon said:
This is what my automotive professor recommends against. Showing a poor repair off even as a learning tool because people will do this on their own vehicles. The 6 bolt fan clutch is garbage. Get rid of it and the wimpy fan it has. But you need to replace both to do it right. Just imagine the damage the Duramax fan would do if it came off center on a 6 bolt clutch.

Fan shroud, radiator, belt, clutch, any hose in line with the shrapnel grenade formally known as a fan, and water pump. Maybe dent the hell out of the hood. If the hood is open, well they ban this: clutch fans and no hoods at the track due to heads separated from bodies.

Do the job right : use a 6 bolt clutch with a 6 bolt fan or any 4 bolt fan with a 4 bolt clutch. To do otherwise is risking property damage and your neck with an open hood and engine running.
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That is good advice. So are there any 6 bolt fans to use other than stock? Aftermarket maybe..
 
This is what my automotive professor recommends against. Showing a poor repair off even as a learning tool because people will do this on their own vehicles. The 6 bolt fan clutch is garbage. Get rid of it and the wimpy fan it has. But you need to replace both to do it right. Just imagine the damage the Duramax fan would do if it came off center on a 6 bolt clutch.

Fan shroud, radiator, belt, clutch, any hose in line with the shrapnel grenade formally known as a fan, and water pump. Maybe dent the hell out of the hood. If the hood is open, well they ban this: clutch fans and no hoods at the track due to heads separated from bodies.

Do the job right : use a 6 bolt clutch with a 6 bolt fan or any 4 bolt fan with a 4 bolt clutch. To do otherwise is risking property damage and your neck with an open hood and engine running.
Click to expand...

Your professor has probably never been a hot rodder and doesn't think outside the box. Your advice is okay for someone who is just a parts changer and has no creativity or problem solving ability. I'm not trying to knock you, but there is no danger in this mod, if you use your head and a little loc-tite. I also don't recommend doing this mod unless you have experiance with fab. or low on coin or in a bind [time].

As far as the clutch being garbage, that's not relative. It's the same construction as other model years of same manufacturer except the amount or placement of bolt holes.

The best way for towing, would be to upgrade to a heavy duty clutch and d-max fan. Which I will do when my six bolt clutch wears out. I finally have it set to wear it comes on at the temp I want and cuts off at the temp I want. I will have to do the same with HD clutch when I get one to retain milage I want to get.

Right now little timmy needs a new pair of shoes.

Nothing but love, just don't pick on the old men who shopped at the junk yard and made parts to fix their Ills before the aftermarket had the solution for all your reliability and speed needs.
 
Well, let's solve the problem.
You are looking for a better fan likely due to a cooling problem. You are on a budget like the rest of us, I understand. In fact if I could afford a Kennedy low temp clutch I would have bought another one, but, I had to get a Hayden 4 bolt to save $150.00 I did not have. I even tried to use another 21" 10 blade fan I had laying around, but, had to buy a better fan because the one I had laying around wasn't pitched deep enough and things kept getting too hot. My delay in obtaining the 1st Kennedy clutch was a big factor in getting my engine hot enough to scuff a piston with the 6 bolt clutch that could no longer lockup much.

Evaluating the 6 bolt clutch:
Did you replace it in the past 5 years? 5 Years is the design life of a clutch as the working fluid looses 200 RPM a year.
Is the clutch covered in a oily crud esp around the thermal spring? This is the clutch bleeding to death, loosing it's working fluid. No working fluid left and the clutch can't lockup or lockup very much.

Other places explain how the factory clutch even new will not stay locked in for an extended pull.

The compatibility with better 4 bolt fans... :skep:

If you have or the PO's has replaced the 6 bolt clutch in the past 5 years I will stand corrected of the term 'garbage'. (You may just need a new fan clutch.)

Another thing to think about is the fan clutch to fan interface. The fans have a circle that fits rather tightly on a hub flange on the clutch. This is like the axle flange that a wheel rim fits on. The lug nuts hold the wheel on, but, the flange absorbs shock from the pot holes and keeps the vehicle up. The lug nuts alone would just break off from pot holes etc.

So the flange on the 4 bolt fan clutches is very important to keep the fan centered in balance. 19", 20", 21" fan diameters is after all the same dimensions used for lawn mower blades bolted to a Briggs and Stratton engine. At 3600 RPM you are close to the speed of sound for blade tip velocity! (Or fan blade tip!)

My professor had a couple things to say about racing:

1/4 mile is cake. Stuff only has to live 1/4 mile: the street is WOT till the top of a several mile hill. Use a fire extinguisher to cool the fan clutch to make sure it is unlocked before the 1/4 mile.

Circle track is a good idea to wire a bolt or nut to the fuel pickup hose so it will follow the fuel in an near empty tank. Turn 4 last lap is a bad place to run the carb dry in 1st place. Next race he had a bolt wired to the fuel pickup...

I thought I was going to be bored to death about spark plugs in class, but, more to them than you would think. Just like this outside the box idea: More to the 6 bolt and 4 bolt fan clutches than just the bolts holding the fan on. So lets make sure we have all the bases covered.
 
More to the 6 bolt and 4 bolt fan clutches than just the bolts holding the fan on.
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I'm listening.. I'm always open to new ideas and covering all bases. That's how we learn what works and what doesn't.

And if my fan wasn't centered it would vibrate and/or hit the shroud. And when towing my clutch doesn't overheat or cut off except when it's supposed to. I do feel sorry for you about scuffing a piston, but that could happen with any part that fails, cheap or high dollar.Or if your fan didn't have enough pitch and other factors contributed to overheating.

I would never recommend a mod that I haven't tested on my own vehicle or atleast pass on a warning that it is as yet untested. After three months and zero issues I thought it safe to pass on that info. I realize that we won't all have the same results on every mod,but it was worth passing on because it works and saved me a boatload of coin.
As for cake in the 1/4, he hasn't done very much if any. Maybe for 1 or 2 passes,cooling isn't an issue,and that's what we're talking about so I'll leave it alone.Every intended use DD or towing/racing has it's area of beneficial mods.

But if you have any constructive arguments I'm feeling spunkier today than most others.


I feel so loved......
Click to expand...


You're loved. Sometimes it's just fun to banter about something.

It's all in good fun and we as individuals not a collective can choose what info to absorb and what to reject.

Feel the love WW, I do.
 
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Actually, I don't have any overheat issues and it is the original clutch. There is no "goo" leaking out either. I r and r'ed the rad to clean it and checked the fan clutch out. Plus I have a new one laying around. I just like to modify the inherent problems of this engine. I do a little here and a little there. Tinkering, ya know. But being retired gives me the time, but not the cash. I got other priority's like a wife with 30 freakin' horses. You wanna talk expensive! I was just reading these posts on the subject and could not find one of them. Still can't find it. Anyway, this cooling mod will be my next project.
 
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