Lock N Roll bolt thread failure
- Thread starter teotwaki
- Start date
teotwaki
Excelsior!
maybe somebody can start their own thread on Pintle failures?
Pintle Hitch Failure
October 1, 2008
Recently a Pintle hitch locking mechanism failed and opened while in
transport. This allowed the trailer to over-ride the service truck on the
highway.
The safety chains held as designed.
Inspect or remove Pintle hitches manufactured by; SAF Holland,
Model # PH-T-100-A
http://www.laynesafety.com/index.php?option=com_docman&task=doc_download&gid=211&Itemid=81
Think of the noise that this failure made!
Lots more failures out there
http://www.arfc.org/commercial/peterbilt/357/recalls/000026252000364636000000316/recall.aspx
PACCAR IS RECALLING 318 MY 2007-2009 KENWORTH T800, W900, AND PETERBILT 357, 365, 367, 378, 379, 384, 385, 386,388, AND 389 TRUCKS EQUIPPED WITH PREMIER TRAILER HITCH ASSEMBLIES. THE PINTLE HITCH ASSEMBLIES MAY HAVE BEEN MANUFACTURED IN A MANNER RESULTING IN A REDUCTION OF FATIGUE STRENGTH OF THE PIVOT PINS.
Consequences THIS REDUCTION OF FATIGUE STRENGTH COULD CAUSE THE PIVOT PIN TO CRACK AND EVENTUALLY BREAK, CAUSING THE TRAILER TO DETACH FROM THE TRUCK WHILE IN MOTION, WHICH COULD CAUSE A CRASH THAT COULD RESULT IN PERSONAL INJURY OR DEATH.
adventureduo
Dave Druck [KI6LBB]
Wow, im lucky our LockNRoll is a past down unit that has never been changed since we bought it 3 years ago. I probably can't even get the nut off if i wanted too 
Thanks for posting up about this Jim and letting everyone know what's going on. I'll be watching this thread.
Thanks for posting up about this Jim and letting everyone know what's going on. I'll be watching this thread.
teotwaki
Excelsior!
Greg Russell at Lock N Roll says that my complaint is the only one he has ever heard of. Given that they are not receptive to complaints I am not surprised. I'll PM you his email address if you'd like to let him know about yours and help me out.
camp'n_hunt
Observer
Guess all day
Well it comes down to everyone and their grandmother can guess all day about it, or if you really want to know send it to a lab. I have had similar failure's with our product; turned out to be defective heat treating after the wheel stud was rolled. There's a ton that comes into play with bolts and nuts and no cut threads aren't weaker, but they do cost about 10 times as much. Only way we found our root cause was sending it to NW Labs for physical analysis.
As for Mr. Grumpy, 1 we all have bad days, 2 when designing a product for such a demanding application there’s going to be more than just a few failures and standing behind your product “no matter what” would put the company under most likely.
Good luck with your hitch.
Well it comes down to everyone and their grandmother can guess all day about it, or if you really want to know send it to a lab. I have had similar failure's with our product; turned out to be defective heat treating after the wheel stud was rolled. There's a ton that comes into play with bolts and nuts and no cut threads aren't weaker, but they do cost about 10 times as much. Only way we found our root cause was sending it to NW Labs for physical analysis.
As for Mr. Grumpy, 1 we all have bad days, 2 when designing a product for such a demanding application there’s going to be more than just a few failures and standing behind your product “no matter what” would put the company under most likely.
Good luck with your hitch.
teotwaki
Excelsior!
Thanks!
Lock N Roll has consistently demonstrated poor handling of my issue whether or not they would have allowed a warranty replacement. They had no interest in photos. They had no interest in me mailing the old hitch piece back to them to look over. When I said that I needed the new piece quickly they screwed up the address and made a tiny one-call effort to contact me and the new piece eventually came a day late. When I said that I was in danger of having the trailer ticketed they said "Hook a chain to it and drag it somewhere".
teotwaki
Excelsior!
The funny thing is that I attributed the discolored look to a partial application of a die to the threads byt the OEM as some sort of thread cleanup process.
When I go to that link that you gave I don't see any mention of applying a die to a rolled thread as a problem. I am interested in learning more.
Last edited:
R_Lefebvre
Expedition Leader
The link provided wasn't intended to be a treatise on the matter. Just a brief description of why rolled threads are stronger. If you want to learn more, you need to read this book:
http://books.google.ca/books?id=NaZ...ok_result&ct=result&resnum=13&ved=0CD8Q6AEwDA
I did about 10 years ago.
http://books.google.ca/books?id=NaZ...ok_result&ct=result&resnum=13&ved=0CD8Q6AEwDA
I did about 10 years ago.
Martyn
Supporting Sponsor, Overland Certified OC0018
I don't think we are looking at a "bolt failure" here. The part in question was no where near a situation where it broke or came apart.
What we are looking at is a situation, two cases that we know of, where the threads were stripped when taken apart.
I'm not sure if the strength of the threads is related or not. Why it's happening is really the question to answer, even with just two cases I'd be interested in an answer.
What we are looking at is a situation, two cases that we know of, where the threads were stripped when taken apart.
I'm not sure if the strength of the threads is related or not. Why it's happening is really the question to answer, even with just two cases I'd be interested in an answer.
R_Lefebvre
Expedition Leader
That's true. "bolt failure" is a bit of an alarming title. The bolt didn't fail. It just failed to come apart easily.
camp'n_hunt
Observer
All things Equal?
When all things are equal yes, rolled are stronger by about 6-8% over a cut thread. But, and it's a big but, all things aren't equal. When you order bolts to be cut tolerances are met, each bolt is inspected. Rolled bolt's come out of machine's at alarming speeds. Out of 5 different manufactures of studs being produced to meet specific spec's we were lucky to find a few that did, and no, none were Chinese manufactured. Besides, that looks like a big bolt and there aren't a lot of plants that roll over 1".
Customer service seems to be dieing everywhere, whether online, over then phone or in person. it's like they don't know that us customer's pay their bills.
When all things are equal yes, rolled are stronger by about 6-8% over a cut thread. But, and it's a big but, all things aren't equal. When you order bolts to be cut tolerances are met, each bolt is inspected. Rolled bolt's come out of machine's at alarming speeds. Out of 5 different manufactures of studs being produced to meet specific spec's we were lucky to find a few that did, and no, none were Chinese manufactured. Besides, that looks like a big bolt and there aren't a lot of plants that roll over 1".
Customer service seems to be dieing everywhere, whether online, over then phone or in person. it's like they don't know that us customer's pay their bills.
teotwaki
Excelsior!
This is a tough crowd! :sombrero: Maybe Bolt Thread Failure?
teotwaki
Excelsior!
I think that you are onto something about the galling.
The nut's threads were pretty toasted. I won't be able to post pictures of it until Sunday
teotwaki
Excelsior!
Well, maybe I'll find another source....:ylsmoke:
Do not waste you money to buy this book,
September 13, 2001
By JAN FILIPECKI
This review is from: Handbook of Bolts and Bolted Joints (Hardcover)
Contrary to what the title suggest, this is not a "handbook". The book is composed from the loose articles written by approximately 30 authors. Every article written in different convention, different language, different approach.
The book contains very limited amount of practical, "handbook like" information, charts, formulas, suggestions, etc. Some chapters are very superficial, the chapter 29, to name only one, "Torque Control of Assembly" completly misses the point. This is neither handbook nor academic textbook.I am dissapointed. I woudn't recomment this book to anybody.