About the Torque-to-Yield Damper Bolts..

[HEMI®Dart]

I thought I could finally clear this issue up. Emailed Cummins with their damper bolts p/n's 4937228 & 3903857 as per David Magnoli's article in the current TDR.



So I get this hokey reply from Cummins:



"Thank you for contacting Cummins. I want to get you the best results for you and your engine. Since Cummins only manufactures the engine, we normally recommend contacting your local Dodge dealer for advice regarding Dodge Ram truck options in regards to parts and services. The information in regards to the parts don't state what to do about the bolts. "

 

[MVenditti]

After torqued should not be reused, replace with new.

 

[Buddy's Ram]

If you are replacing the damper; Geno's supplies the new bolts with the fluiddampr.

 

[HEMI®Dart]

"I’ve read on the TDR forum that these bolts

should not be reused as they are said to be torque-to-yield, but

the Service Manual does not say anything about using new bolts. "



https://www.turbodieselregister.com...al-topics-inspect-your-harmonic-balancer.html

 

[Joseph Donnelly]

I don't believe the damper bolts are torque to yield. I have re-used them repeatedly.

 

[Allnew2Me]

I have not found anything in print that says they are torque-to yield either. The service manual does not say to replace them, as they do in other circumstances. It is still cheap insurance though.

 

[HEMI®Dart]

Genos garage

FLUIDAMPR HARMONIC DAMPER ('03-'07, 5. 9L)-Dodge Cummins Diesel Truck Accessories – Geno’s Garage

 

[Bill Lins]

Mebbe the bolts supplied by Fluidampr are TTY but the OEM ones are not?

 

[Parks]

I do not believe they are TTY either. I have re-used them before with no problems.

 

[Joseph Donnelly]

Cummins torque to yield (or angle) head bolts have T+<90 on them meaning torque plus turn 90 degrees. They actually haven't yielded, as they can be re-used at 115 to 120 ft-lb afterwards. The marine camshaft retaining bolt, however, has a necked down shank and won't be re-usable after the first torque. I prefer to use a grade 10. 9 bolt there as it is cheaper and reusable. Damper bolts have 12. 9 on them, meaning their grade, which corresponds to Grade 9 on the American scale.