6.7 fan pulley on a 5.9 engine, will it work?

[07 ThunderRoad]

My warranty is running out of time and miles. Starting to think about mods to increase my engines usefull life span. I don't need the extra HP. I like the fluid damper but don't like the problem with not being able to change the belt without removing the damper. I'm wondering if any one has checked the 6. 7 pulley for fit and damper / belt clearance. What is the dia. differance between the 2 pulleys? Will this work?

 

[Prairie Dog]

I'm sure more info will follow but the short answer is no, it wont fit. The 6. 7 HB will hit the pulley above it. It looks like you would have to change 1 or more other pulleys to achieve this.

 

[07 ThunderRoad]

I'm sure more info will follow but the short answer is no, it wont fit. The 6. 7 HB will hit the pulley above it. It looks like you would have to change 1 or more other pulleys to achieve this.

I don't want to use the 6. 7 damper. From what I have read, the 6. 7 damper is larger and the fan pulley is smaller. I am thinking of using the 6. 7 pulley, for the fan, and a new fluid damper (from Fluidamper).

 

[Prairie Dog]

I think you might find the belt is too long in that situation but I'd sure like to know for sure. .

 

[seafish]

That's an interesting idea... I would think that the problem would be retaining the correct amount of tension if the 6. 7 fan pulley is much smaller then the 5. 9, with fluidamper being the same diameter as the oem damper.

Myself, I am VERY interested in placing BOTH the 6. 7 fan pulley and 6. 7 viscous damper on my 5. 9. I have heard that it works, bit have NOT been able to confirm that with anyone who has actually done it.

 

['strokeThis_'07]

Fan pulley on both 5. 9 and 6. 7 are exactly the same size, as is the idler pulley right above the fan pulley. The balancer pulley is within roughly a quarter inch of each other, by a quick eyeball (about 8in on 6. 7, 7. 75 on 5. 9).

 

[07 ThunderRoad]

On another thread (somewhere on the internet) I read that a 6. 7 damper was fitted to a 5. 9 but the fan pulley was against the edge of the damper. If I had a 6. 7 engine ser. number, I can look up the fan pulley part number for both engines. The differance in sizes should be less than . 125" .

 

[mwilson]

Please have a look at this thread from last spring. .

The fan pulley is different between the 5. 9 and 6. 7 engines.



https://www.turbodieselregister.com...95-fluidamper-vs-ati-harmonic-balencer-3.html



Mike.

 

['strokeThis_'07]

The fan pulley is 7" on both the 6. 7 and 5. 9. I just went out to the garage and measured both, like I did lastnight. And the idler pulley right above is 4 7/8" on both. I can't measure any accessory belts because my 6. 7 didn't come with any, but the damper is indeed larger on the 6. 7. Like I said, roughly 1/4" difference between the two where the belt rides. I'll go out and re-measure...

 

[mwilson]

E-mail me both engine serial numbers and I will check it on Cummins if you want... .



-- email address removed --.



Maybe there is some other difference rather than diameter???

Fan clutch still attach the same with a right hand thread????



Mike.

 

[07 ThunderRoad]

The fan pulley is 7" on both the 6. 7 and 5. 9. I just went out to the garage and measured both, like I did lastnight. And the idler pulley right above is 4 7/8" on both. I can't measure any accessory belts because my 6. 7 didn't come with any, but the damper is indeed larger on the 6. 7. Like I said, roughly 1/4" difference between the two where the belt rides. I'll go out and re-measure...

Is it possible that the pulley for the fan is shaved back to gain the clearance? Is the damper out farther from the engine block? (this need only be . 125" for belt removal clearance) The dia. of the pulley and damper is not the only way to gain clearance. If you can take another look at the 2 engines and check the measurements from the block to the damper and the pulley, that may explain what the difference is. It has been said that the 6. 7 damper touches the 5. 9 pulley when installed on the 5. 9 but, on the 6. 7 there is plenty of clearance for the belt removal.

 

[JJPage]

I like the fluid damper but don't like the problem with not being able to change the belt without removing the damper

I still have my factory damper, are you saying that with a Fluid damper installed, you need to remove the damper to change the belt? I had not heard this before, and I have read quite a few threads on the Fluid damper.



If that's the case, I don't like that situation at all.

 

[07 ThunderRoad]

Thats what I have read. I would like to know the facts from someone that has done the install of the FD on a 5. 9 and than changed the belt.

 

[Prairie Dog]

Thats what I have read. I would like to know the facts from someone that has done the install of the FD on a 5. 9 and than changed the belt.

I have the FD and I think it may be possible the pull the belt between the two, perhaps while turning the crank in the same direction. There seems to be about ~. 08" clearance. It may just cut the belt though.

 

['strokeThis_'07]

Is it possible that the pulley for the fan is shaved back to gain the clearance? Is the damper out farther from the engine block? (this need only be . 125" for belt removal clearance) The dia. of the pulley and damper is not the only way to gain clearance. If you can take another look at the 2 engines and check the measurements from the block to the damper and the pulley, that may explain what the difference is. It has been said that the 6. 7 damper touches the 5. 9 pulley when installed on the 5. 9 but, on the 6. 7 there is plenty of clearance for the belt removal.

5. 9, front cover to front face of damper-2 3/8"

6. 7, front cover to front face of damper-2 11/16"



The 6. 7 damper is tapered, where the 5. 9 damper is not. The fan pulley, as well as the idler pulley above it, are the same. They share a mount, which mounts in the same spot on the block. Both mounts are identical.



6. 7 damper

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5. 9 damper

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6. 7 fan pulley (fan removed)

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5. 9 fan pulley

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6. 7 idler

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5. 9 idler

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[seafish]

stroke, MANY thanks for all the pix and measurements.
Is there any chance that you can get a measurement of the DIAMETER of both the 5. 9 and 6. 7 damper??

ALSO, I think that some of us would appreciate a WEIGHT of the 6. 7 damper as so far we only know that it's shipping weight is 35 pounds, but it would be great to learn it's ACTUAL weight!!!! (may as well throw in the weight of the 5. 9 damper for the hell of it??)

Hope that it's not too much trouble. . TIA

PS--seems like you are going to be the person to figure out how all of this is going to fit together so that a person can use a 6. 7 oem damper on the 5. 9 CTD, while still leaving enough clearance to change the belt without loosening the damper again... . after all, you seem to have all the parts handy, and certainly you have the skills!! :-laf Oo.

 

[07 ThunderRoad]

I would like to see pics and put this issue to bed. Can we talk you into installing the 6. 7 damper on the 5. 9 engine with the fan pulley installed. Also, is the tone ring index tooth in the same spot on both dampers? I want to thank you 'strokeThis_'07 for your valuable information and the time you have spent on this.

 

[seafish]

I would like to see pics and put this issue to bed. Can we talk you into installing the 6. 7 damper on the 5. 9 engine with the fan pulley installed. Also, is the tone ring index tooth in the same spot on both dampers? I want to thank you 'strokeThis_'07 for your valuable information and the time you have spent on this.

X2... . :-lafOo.



That would be fantastic if you are in a position to do that... many of us would be forever grateful... and your name would go down in the history of CTD forums as the person who figured it all out!!! :-laf



FYI--I have posted on 3 different forums and at least five different threads, and still no one has been able to give a definitve answer as to what parts and mods need to happen to get this done.



And IMHO, it IS worth doing as the 6. 7 oem viscous damper not only costs less but is also heavier then the Fluidamper.

 

['strokeThis_'07]

Haha, thanks fellas. Yeah I can bolt it on tomorrow and grab some pics before I drop the 6. 7 in. Should be able to pull the dampers and weigh them also. I held each up to the other block (didn't bolt them on) and they both looked to clear.

 

[cerberusiam]

FYI--I have posted on 3 different forums and at least five different threads, and still no one has been able to give a definitve answer as to what parts and mods need to happen to get this done.

Yep, all kinds of talk and prognostication with no hard facts.



Stroke and TDR will the firstest with the mostest to figure this out for sure.