Duramax Fan Blade on 95 Stock Clutch?

[btsayles]

Does anyone know if a duramax fan blade can be directly bolted to a 95 stock clutch? And if so, what year d-max blade. Since the thread in the stickys about adjusting the kick in temp. I would rather keep the stock clutch and just replace the blade.

 

[Dave Barbieri]

Does anyone know if a duramax fan blade can be directly bolted to a 95 stock clutch?

It bolted straight up to a stock (heavy duty) clutch for my 94 1Ton. I ordered mine form Rock Auto. I'll check the invoice tonight for the part number(s).

 

[handcannon]

It depends on your fan to clutch bolt pattern. The earlier years used a 6 bolt pattern and this will not work with a DMax fan. The 4 bolt pattern of the later years will work with the DMax fan. I'm not positive of the year of the 6 to 4 bolt change, but my 94 had the 6 bolt, and 97 has the 4 bolt pattern.

Here's what I used to get the DMax fan to work on my 94. I got a severe duty clutch for a 97 from NAPA (according to Rockauto up to 99 will work). This will bolt to the water pump and have the 4 bolt to fan pattern needed for the DMax fan. I used AC Delco # 1580690 from Rockauto for the 01 to 05 DMax fan.

Hope this helps.
Don

 

[robzombie4551]

I have the 6 bolt clutch and bought the 2001 fan. It bolts up and lines up fine. You don't use the holes for the fan. There are 4 holes that are offset and just barely line up with the clutch. I found this out by accident and was going on a trip and needed the fan bad. I was even going to drill new holes to make it fit because sending it back or buying another clutch wasn't an option at the time. after spinning it around I noticed that it would bolt up and it doesn't hit the shroud and is in center and balanced. It's been on there for 3 months and no worries.

 

[Acesneights1]

Good info. I have a Hayden SD clutch for my Burb waiting to go on and the Dmax fan should fit it then.

 

[btsayles]

I have the 6 bolt clutch and bought the 2001 fan. It bolts up and lines up fine. You don't use the holes for the fan. There are 4 holes that are offset and just barely line up with the clutch. I found this out by accident and was going on a trip and needed the fan bad. I was even going to drill new holes to make it fit because sending it back or buying another clutch wasn't an option at the time. after spinning it around I noticed that it would bolt up and it doesn't hit the shroud and is in center and balanced. It's been on there for 3 months and no worries.

Thank you for the info guys. I did the research and here is the rules for the fan to clutch with 6 bolt configuration. '96 the clutch changed to the 4 bolt fan to clutch. Also, in '99.5, the 4 bolt clutch to water pump changed to the threaded shaft. Make sense everybody? Using the wrong holes, it can be done on the 6 bolt fan to clutch, but I don't like that. That's just IMO.

Someone with a 6 bolt fan to clutch has four options to switch to a duramax fan and 185 deg.F clutch assy for the lowest prices I could find. Remember there are discount codes on our site here for rock auto too:

1) Buy the 185 deg. F clutch and d-max fan assembly through Walt for $200
2) Use the wrong holes on the 2001 d-max fan blade w/ original clutch and adjust the bi-metal strip on the clutch to desired setting, rock auto fan only price $54.79; p/n 1580690.
3) Buy a stock or severe duty clutch for a '96 or later from anywhere and adjust the bi-metal strip. Rock auto price for stock '97 clutch $95.79; p/n154674. Hayden Clutch$142.79; p/n 2839. $54.79 for fan; p/n 1580690. Stock total $150.58. Hayden Total $197.58.
4) Junk yard clutch like i just did for 20 bucks, used the clutch bimetal spring adjusting link in the stickys, buy the d-max fan from rock auto with coupon code. Total cost, 75 bucks. :thumbsup:

I hope this really lets everyone know what they are up against for '95 and older. I hope it helps too!
NOTE: The Hayden Clutch engauges at 170 deg. F. That's a little low for me. I usually run at 185 deg. F. I don't want the fan running constantly. I set mine for 190. For info how to adjust the temp on your fan clutch, check the stickys. http://www.thetruckstop.us/forum/showthread.php?t=12265

 

[WarWagon]

Old fan clutches are high risk. Their design life is 5 years as they loose 200 RPM per year due to age and wear on the silicone fluid in them. Bill Heath has blogged that the OEM clutches did not hold in when needed for extended hills further adding to the ruined 6.5 engine pile. Clutches leaking out the silicone fluid, aka, beading to death is common - no fluid = no lockup. When you need the fan and the clutch is worn out and does not perform you have to shut your engine down as the temp starts to run away or you will ruin your engine. One hard hill is all it takes to crack the heads. Add a trailer and piston scuffing and complete engine failure is possible if you push the temp up. Ask me how I know.

If that 6 bolt clutch is the the factory original and coated with an oily grime get rid of it ASAP! The cheapest you can change the engine for is around $1500 vs. the $110 clutch. Don't be too cheap on a critical part like the limited life fan clutch.

The Kennedy clutch with a HO pump and 180 T-Stat is the best cooling you can get for towing. Dmax fan is even better. Bill Heath's parts may be the absolute best setup, but, the Kennedy setup will do the job esp in AZ. You can't go wrong with either product.

I hear bad about SS Diesel and if their clutch does not kick in lower it isn't doing you any good.

 

[handcannon]

I have the 6 bolt clutch and bought the 2001 fan. It bolts up and lines up fine. You don't use the holes for the fan. There are 4 holes that are offset and just barely line up with the clutch. I found this out by accident and was going on a trip and needed the fan bad. I was even going to drill new holes to make it fit because sending it back or buying another clutch wasn't an option at the time. after spinning it around I noticed that it would bolt up and it doesn't hit the shroud and is in center and balanced. It's been on there for 3 months and no worries.

Rob

Your post got my interest up. Last weekend was the test run for my truck

with the new fan and clutch while towing the travel trailer. I was

dissappointed to say the least. I removed the fan/clutch combo today to

mod the bi-metal spring on the clutch. I looked for the holes you talked

about, not there. The only other holes were extremely large, too large for

bolts. They were about 1" wide and maybe 2" long. I guess not all DMax fans

were created equal.

Don

 

[btsayles]

Rob

Your post got my interest up. Last weekend was the test run for my truck

with the new fan and clutch while towing the travel trailer. I was

dissappointed to say the least. I removed the fan/clutch combo today to

mod the bi-metal spring on the clutch. I looked for the holes you talked

about, not there. The only other holes were extremely large, too large for

bolts. They were about 1" wide and maybe 2" long. I guess not all DMax fans

were created equal.

Don

That's what I was thinking too just by looking at the pictures of the fan. The only way I could see using the 6 bolt clutch with the d-max fan would be to do some serious compass measuring and hole drilling. Not a fun time to me to get it right. Otherwise it would require using only four of the bolts and some big azz washers. Now were adding weight to the outside of center on the clutch. Not well balanced either I would imagine.
Also, to the previous post about clutches losing 5 deg because of leaking a year. It would not engage at all for me because I have never reached 230 deg obviously my truck is 15 years old if you do the math. That's also why one adjusts their bi-metal spring to keep it in check. I don't believe it. Could just be the fallacy of positive instances? But. $200 for a hayden 175 deg clutch and d-max fan from rock auto as previously stated. Sounds like the way to go to me. JIMO

 

[robzombie4551]

Okay here it goes. As I said I was in a pinch. Those big holes are the ones I used. No washers were needed. The shoulder of the bolts grab the metal and center the blade.

The threads of the bolts just make contact with the outer edges of the holes and center the fan on the clutch.

I'm not telling anyone to do this but since it has been on there for 3 months and I'm Al bundy, and have zero problems with it. I will save my money for more important things.

Now when it's time to replace the clutch maybe I'll drop the coin, but if your're worried about that then why bother with fan clutch mod??? Just blow all your money on stuff if you can afford to.

This is how most hot rod solutions come about, IE; Try to save coin,improve on the factory set up, or in my case, had to get down the road that day.[ Make it work] JMHO.

SINCERLY, ROB ZOMBIE

 

[WarWagon]

...
Also, to the previous post about clutches losing 5 deg because of leaking a year. ...
That's also why one adjusts their bi-metal spring to keep it in check. I don't believe it.
...

Let me clear up it is an RPM loss not a temperature setting that wears out.

http://www.aa1car.com/library/cooling_fan_clutch.htm

Defective fan clutches are a common and often overlooked cause of engine overheating. The shear characteristics of the clutch fluid gradually deteriorates over time, with an average loss in drive efficiency of about 200 rpm per year. Eventually slippage reaches the point where effective cooling is no longer possible and overheating results. (On average, the life of a fan clutch is about the same as a water pump. If one needs to be replaced, the other usually does too.)

If the fan clutch shows signs of fluid leakage (oily streaks radiating outward from the hub of the clutch), spins freely with little or no resistance when the engine is off, or wobbles when the fan is pushed in or out, it needs to be replaced.

 

[Odlaw]

Just curious, what is the difference between the d-max fan and 6.5 fan? (performance wise) - I understand the differences between the other clutches vs. OEM 6.5 but was just wondering about the fan itself.

Thanks
Smitty

 

[ak diesel driver]

I believe it has more blades and a larger dia.

 

[robzombie4551]

9 blades, composite or plasitic and a steeper blade pitch to move more air at lower rpms.

 

[Steve93mustanglx]

Pics of stock 95 fan and clutch

Here is a pic of a 95 stock fan clutch. 6 bolts. I bought a newer model fan clutch from THEFERMENATOR (sp??) last week. It is to the left and is 4 bolts for fan mounting. I bought a 2001 Dmax fan. Bolted right up.

Had a 1/2 inch clearance all around. Tickled pink! Definitely pulls a good amount of air at idle. Did not see temps over 195 today in 95 degree heat.

Big fan of this fan):h