Papaduck. help a brother out here! I picked up the parts for the 6.7 upgrade this AM and after I opened the boxes, I had a brain fart! . Is the reason I'm changing the 5.9 fan pulley to compensate for a larger diameter of the 6.7 damper? As I'm writing this, I'm feeling like "why am I overthinking this, just swap the parts"!

 

Read post #17 in this thread. I think it's to line up the belt properly. Hopefully Papaduck will chime in.

 

The reason you are changing the fan pulley is the diameter of the fluid damper is larger by about 3/4 inch. The fan pulley is the same as the old one but it has an offset that allows it to clear the damper. Look at both pulleys and you can see the differance.

 

You're right, I guess I will have to see them side by side.

 

 

Momma always said "Be careful what you wish for"

Thanks, Guns

 

Update,

Ok, I put 3k miles on the truck the past two weeks with 3/4 of those pulling the 5ver. The Fluidampr did suppress the vibrations very well. I can now (un)comfortably say the vibrations I have been trying to find are caused by the motor.

 

have you changed 1 injector? i heard a matching set is critical???

 

Did the damper, little if any change in vibration. Beginning to think it may be driveline. Perhaps one of the new U-joints went South. Stay tuned!

 

I just replaced 1 injector, that's all I could afford and I also notice a vibration up in the rpm range since then. Can't pin it down due to my 2006 wacked tach issue but it is at the same rpm.

 

Do yourself a favor and drop the driveshaft center bearing mount one inch. It makes a huge difference. You just have to make a spacer. The deflection angle is too large. I went through 2 sets of "U" joints before I did mine. Remember, the larger the deflection angle,the greater the velocity modulation from the "U" joint. Straightening mine out really increased smoothness.

 

Update on this vibration,

It has now been awhile since I first noticed this problem and it is now to the point where I can feel it empty.

Always between 1500 and 1900 rpm in second, third and OD most prominent with the torque converter locked up as then the motor and transmission are physically locked together.

Does anyone know of a tool that can sense vibrations and can be remotely monitored? Or some way to determine the source of a harmonic vibration?

 

Wondering if you ever fixed this problem I have a 06 mega cab and it's doing same exact thing, any help would be great, thanks

 

I have an 06 with identical problem. Pulling 6k pound trailer, up the slightest hill, I have vibration. I saw some type of silicone dripping from front of engine. I didn’t think the 06 had a fluid dampener. I thought it was rubber. My truck is in the shop that replaced the transmission with a BD last year for a transmission leak. He seems to think the issue is the harmonic balancer. I’ll know next week when he works on it.