Are my JD toothbar nuts defective or special?

[ragkar]

Yesterday I had a heck of a time removing those toothbar nuts and had to resort to an impact wrench. When I examined the nuts I found that the top thread is damaged on both resulting in an extremely difficult tight down or loosen.
The bolts are marked TVS 10.9 which my web search leads me to believe are special hardness. The nuts have and indentation on the top that crushes the top thread and causes the tight fit.
I'm thinking that if I retain the bolt but replace the nut with a lockwasher and nut, I'll be able to remove and replace them easier. I don't want to cause safety problems but I think that reusing the special bolt will work out.
What do you think?

 

[swines]

Yesterday I had a heck of a time removing those toothbar nuts and had to resort to an impact wrench. When I examined the nuts I found that the top thread is damaged on both resulting in an extremely difficult tight down or loosen.
The bolts are marked TVS 10.9 which my web search leads me to believe are special hardness. The nuts have and indentation on the top that crushes the top thread and causes the tight fit.
I'm thinking that if I retain the bolt but replace the nut with a lockwasher and nut, I'll be able to remove and replace them easier. I don't want to cause safety problems but I think that reusing the special bolt will work out.
What do you think?

The nuts are distorted thread lock nuts. You can certainly use a lock washer and regular nut if there is enough threads for both. Generally, the distorted thread nuts are used when the bolt threads don't protrude far enough to get the nut fully seated on the threads with the lock washer under it.

Class 10 is equal to a Grade 8. Class 10.9 is heat treated for stress relief. If you use a Grade 8 it should be equal in strength.

 

[Willl]

No worries man, your nuts are normal.
(can't believe I just said that)

 

[ragkar]

Thanks for the good advice. I'm going to look for replacement rustproof nuts tomorrow.
I think that I may attack the hooks on the toothbar with an angle grinder to make it reinstall easier.
I noticed that the dealer used lithium grease on the thread bolts to make the nuts go on easier.
off topic - the wierdest advertisement headline that I've seen is one that said "Your balls saved my life" It was an advertisement in a flying magazine for those orange balls that are put on elevated power lines to make them more visible for landing pilots.

 

[johnk]

I like to double nut them so no threads are showing. You can whack em, band em and whatever and they still come off. That way you won't distort the threads. I use grade 8's..