• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Which upgraded fan is better?

You are saying the Kodiak Dmax fan clutch will thread onto a 99+ spin on 6.5TD WP.
Yes, that is correct. I'm running this setup on my Suburban. Spin on water pump, 2886 Hayden clutch with 15010202 Duramax fan.

Horton may just make an elec clutch for said Kodiak...See where I'm going....;)
Its the Kodiak with the Duramax engine. I think they list it as 6.6L Diesel.
 
The threaded water pumps are also better than previous editions. If upgrading water pumps on any 6.5 I would put the 2000 (1999.5+) water pump on it.

Kennedy Diesel:
$250.00 clutch
$65.00 fan ($75.00 Dmax also same price at Dealer wholesale account.)
$100.00 HO 4 bolt water pump at Autozone.
$15.00 180 RS Thermostat

Kennedy Diesel $430.00 total.

Heath Diesel:
Total $629.00, fan, t-stat, clutch. And the price went up in the past year. You will not do much better on your own for these parts.

Kennedy does the job.

Yes being cheap the spring mod is attractive - but there is such a thing as being too cheap and having to do the job over a few times to get the calibration 'close'. Some people don't mind doing a job over. But, when your engine depends on the clutch and you have a load to haul: I have already paid the price with a blown engine and understandably will NEVER take this risk again. :skep: 1st thing that comes off my 6.5 when I get them is the fing worthless factory clutch and garbage 6 blade fan. Then and only then do I pull and clean the radiators as step #2 and step #3 is a HO pump before reassembly.

Yes, buddy is correct: better for latest GM's design that Heath sells, thread on water pump, for balanced flow to each bank. See the subscription maxxtorque article on the 1995 suburban. The teaser is long enough to explain the balance flow problem. clicky... However, I do not see the need for it running as hard as this engine can like I did. Dual t-stats are said elsewhere to keep the block pressure down with regard to freeze plugs etc - however the water pump will not generate anything like the 16 PSI your radiator cap will and is Heath's philosophy - running a single stat with a HO pump.

So it is hard to justify the additional $200 for the PIA thread on pump and clutch. Try and get one loose without the proper tool or an air chisel and PIA is accurate. Perhaps a racing type restriction washer could be fitted to the 4 bolt HO pumps or t-stat housing to balance the flow out?

Acesneights1 and others have the best idea of on/off clutches with no 'delay' for the extreme hard working 6.5's. EVclutches are not easy to do so they are out of the running. The on/off setting can drive you a little nuts unloaded and AC pressure switches will be a can of worms - but doable.

We should get Slim Shady involved in redesigning the Hummer clutches for reverse rotation as a PS pump tap and switch setup is available (and simple) for Hummers. :thumbsup:
 
Ok, the Dmax fan is 4 bolts, Hayden fan is 6 bolts, so do I just redrill the fan? Its a tad loose around the center.
 
So it is hard to justify the additional $200 for the PIA thread on pump and clutch. Try and get one loose without the proper tool or an air chisel and PIA is accurate. Perhaps a racing type restriction washer could be fitted to the 4 bolt HO pumps or t-stat housing to balance the flow out?

This is my feeling, i don't think the spin on WP is worth the trouble for what I want to do with my truck. a 97 model 4 bolt will do the job, imho
 
If you are upgrading from a 92-96 low flow pump, with a new clutch and new fan, there is no reason to not go for the spin on clutch. If you are not replacing your 97-99 HO water pump then sure, you may not want to add the expense. i didnt say you had to buy a Heath kit, no need to swap out T-stat housings either. If you already are into the mod with the new clutch and fan and decide later to upgrade to a HO pump then yeah, you might not want to also buy a new clutch. If you only want to do it once, you might as well do it right the first time right?

I dont understand how you can consider the fan clutch mod unreliable. You take any clutch and mod it to engage whatever temp you want. It can be a new clutch of any flavor. If youre paying someone else to calibrate your clutch then you still have to verify it.
 
I have the same setup you have and I know some of the people here disagreed with how I mounted it but,I would avoid drilling because if you're off-center the fan may hit the shroud or atleast be out of balance.

I centered the fan on the clutch and lined up the semi circular holes,which there are four of , with the holes in the clutch and the shoulders of the bolts grab it fine and center the fan.

Your only other choice is to buy a 4 hole clutch. I'm only sharing with you because it's been on my truck for over 20.000 miles with no issues so I haven't replaced the clutch and won't until it fails. Hope this helps.
 
I have the same setup you have and I know some of the people here disagreed with how I mounted it but,I would avoid drilling because if you're off-center the fan may hit the shroud or atleast be out of balance.

I centered the fan on the clutch and lined up the semi circular holes,which there are four of , with the holes in the clutch and the shoulders of the bolts grab it fine and center the fan.

Your only other choice is to buy a 4 hole clutch. I'm only sharing with you because it's been on my truck for over 20.000 miles with no issues so I haven't replaced the clutch and won't until it fails. Hope this helps.


I was thinking of doing that too, and I just might drill a few holes as well.
 
If you are upgrading from a 92-96 low flow pump, with a new clutch and new fan, there is no reason to not go for the spin on clutch. If you are not replacing your 97-99 HO water pump then sure, you may not want to add the expense. i didnt say you had to buy a Heath kit, no need to swap out T-stat housings either. If you already are into the mod with the new clutch and fan and decide later to upgrade to a HO pump then yeah, you might not want to also buy a new clutch. If you only want to do it once, you might as well do it right the first time right?

I dont understand how you can consider the fan clutch mod unreliable. You take any clutch and mod it to engage whatever temp you want. It can be a new clutch of any flavor. If youre paying someone else to calibrate your clutch then you still have to verify it.

I suppose with an IR temp gun and a heat gun you could cal the clutch close to your liking by shifting the 'full open' hot position of the valve by 10-15 degrees lower. Heat the clutch and record the temperature it is full open. Then adjust it and heat it again to make sure it is full open at the 10-15 degree lower temp. This does not guarantee the curve of locking up will be the same as a factory low temp calibrated clutch that is offered.

Hayden clutches tend to turn on lower then the factory set points. I think I read this in a parts catalog for the 350 TBI Yukon gasser. I can't put my finger on anything to back it up at the moment. Just something to keep in mind when modding a new clutch.

I am concerned that the modded clutch would not turn on low enough on the first hill loaded and result in the customer coming back to your shop after the mod. This is the risk the OP's post is taking on a customer, not his, truck. I would suggest the customer be given the option of saving $150 or spending it to CYA. Risk of modded clutch failing for any reason and ruining the engine - that Hayden will not cover now due to the mod. Customer's budget my say do a mod. The same reason budget sometimes dictates not going to a thread on setup. (Cheaper parts source may soften this fact.)

Truthfully the IDI 6.5 should not be pushed this hard as fuel economy goes down quick the harder you load it. Other solutions should also be thought of like ceramic coating the prechambers etc.

We beat this to a dead horse before here:
http://www.thetruckstop.us/forum/showthread.php?11413-88894035
 
Last edited:
You wouldn't by chance use this for bank robberies, or cranky wives would you ???

No, just cranky wives and kids, :rof:

I suppose with an IR temp gun and a heat gun you could cal the clutch close to your liking by shifting the 'full open' hot position of the valve by 10-15 degrees lower. Heat the clutch and record the temperature it is full open. Then adjust it and heat it again to make sure it is full open at the 10-15 degree lower temp. This does not guarantee the curve of locking up will be the same as a factory low temp calibrated clutch that is offered.

Hayden clutches tend to turn on lower then the factory set points. I think I read this in a parts catalog for the 350 TBI Yukon gasser. I can't put my finger on anything to back it up at the moment. Just something to keep in mind when modding a new clutch.

I am concerned that the modded clutch would not turn on low enough on the first hill loaded and result in the customer coming back to your shop after the mod. This is the risk the OP's post is taking on a customer, not his, truck. I would suggest the customer be given the option of saving $150 or spending it to CYA. Risk of modded clutch failing for any reason and ruining the engine - that Hayden will not cover now due to the mod. Customer's budget my say do a mod. The same reason budget sometimes dictates not going to a thread on setup. (Cheaper parts source may soften this fact.)

Truthfully the IDI 6.5 should not be pushed this hard as fuel economy goes down quick the harder you load it. Other solutions should also be thought of like ceramic coating the prechambers etc.

We beat this to a dead horse before here:
http://www.thetruckstop.us/forum/showthread.php?11413-88894035

I've done it before on 2 customers and they both noticed a difference, with stock fans and clutch's so I am not worried.
 
Kennedy Diesel:

Heath Diesel:
Total $629.00, fan, t-stat, clutch. And the price went up in the past year. You will not do much better on your own for these parts.

:
The thread on hub water pump is double the price of the 4 bolt. I know, I bought one a few months ago for my dually and I get shop price at Advance auto and the New 99.5+ WP was a tad over 200$ so Heath is not that far off. I am toying with the idea of the Kennedy Fan on my burb though cause it's a 98 and has the 4 bolt WP. As far as the Dmax vs steel I had both and I personally have had better results with the 9 blade steel on an HD Clutch. I have many many annual threads on 6.5Td's and overheating and I have tried it all....:D
 
Ears perked up here, await confirmation!

I spoke with Horton today. They do not offer a clutch for the Kodiak with dmax, only the Kodiak with 3116 Cat. I spent an hour looking at diagrams from their online catalog and 30 pages worth before I had to stop. I didn't look at them all but the closest thing I could find was the proper rotation but the nut was m30rh and ours are m36rh. If the thread on the WP could be turned down and re threaded to m30 it would work I think but I am not sure who if at all could do such machine work.
 
I really think if someone could design an Elec clutch for the 6.5TD it would be the greatest thing ever made. I would go as far as to say it would be a must have for anyone who tows. It should not be that hard but when I talked to R&D at Horton they were not interested.
Horton is the only one who makes these kinds of clutches that I am aware of.
 
Kennedy Diesel:
$250.00 clutch
$65.00 fan ($75.00 Dmax also same price at Dealer wholesale account.)
$100.00 HO 4 bolt water pump at Autozone.
$15.00 180 RS Thermostat

Kennedy Diesel $430.00 total.

Heath Diesel:
Total $629.00, fan, t-stat, clutch. And the price went up in the past year. You will not do much better on your own for these parts.

Peninsular take off spin on type water pump $65
Hayden Truck duty fan clutch $110 (Summit)
New Duramax fan $75
You are at maybe $300 with shipping and a thermostat.
You just gotta shop around and make your own setup.
 
The other option would be electric fans but I have yet to see an elec fan setup that can pull the same amount of air as the engine driven one. I don't see that possible.
 
Back
Top