New problem tighten bolts

[ch1ch2]

I always knew JD liked to be proprietary, but I guess I never knew how much.

 

[bcp]

What does JDM stand for? and, ASTM?
I always thought SAE was the standard.

JDM = John Deere Material

SAE = Society of Automotive Engineere

ASTM = American Society for Testing and Materials

 

[jd110]

The clutch pack to flywheel bolts should be 3/8" bolts. Grade 5 should be 35 ft/lbs and grade 8 can be up to 50 ft/lbs/. For this application I have always torqued them to 35. Never had one come loose in 40 years. Are you sure the spec you were looking at wasn't for the flywheel bolts that hold it to the crankshaft? They should be 120 ft/lbs if grade 8. 85 ft lbs if grade 5. I would not use 120 inch lbs. That is not enough... equivalent to 10 ft/lbs.

By the way, I think the stripping sensation you were getting was the bolts stretching. Compare to a new bolt and you will see the difference in length.

 

[dragoneggs]

I always knew JD liked to be proprietary, but I guess I never knew how much.

Many large OEMs create their own standards... usually very similar to National or Industry standard but they may have a specific requirement or two that they want to be assured of, and they can control their purchasing and receiving better in some cases. Does drive cost though because often it means additional qualification/certification testing to verify.

 

[ch1ch2]

We have it together. Used new grade 8 bolts. We torqued it to 40 ft/lbs and used loctite. Just need to finish the little stuff which we will finish tomorrow.
Thanks for all the information and adding to my education.