Good Evening all,
I am having a serious problem with the ring gear bolts for a new ruckstell. I broke 3 of them off, and stripped the threads off of another trying to torque them to 35ft/lbs. After I broke the first bolt I switched torque wrenches. Although both of my torque wrenches are used to build aircraft engines and are sent out for calibration check frequently.
See photo below. Bottom is an uninstalled bolt, middle is one which the threads pulled off of, and it broke cleanly, top is one which broke "dirty"
The manual says to torque to 35ft/lbs, and that the fasteners are good to 60ft/lbs. Bolts were installed according to the rebuild manual.
Has anyone else experienced this issue? it is quite alarming. The only thing I can think of is they were not heat treated?
Anyway if anyone has any suggestions please let me know.
If you are using Chaffins, they shouldn't do that. Why do you need to torque them? Just do it by hand like has been done for the last90 years.
I bought the kit from Lang's (I assume they get it from Chaffins? It has their rebuild manual with it)
The reason I was torqueing it down, is there is a called out torque spec in the manual for 35ft/lbs. The bolts are too small for that torque but the manual points this out, and mentions that they should be good for 60ftlbs. I believe that when there is a called out spec it should be followed.
Anyway if anyone has any thoughts on this I would like hearing if I am the loose nut here.
Are they new bolts or old?
I was taught to NOT re-use the old ring gear bolts.
: ^ )
you're doing what is called for in the manual. I'd sure put a file to them and see if they are hard. Please report back what you find. That sounds like faulty heat treat on the bolts if in fact you did not somehow overtorque them (and it sounds like you did not).
I will be where you are today, soon, and would like to have this little issue put to bed before I get into it, too.
I used original bolts and Larry's method of tightening.
Back in the 80's I had my first ruckstell rebuilt by an old gentlemen who had done many of them ' Because of his age and weakness in his hands he did all his bolt tightening with an air impact wrench. I'm sure he over torqued the ring gear bolts. On my first drive I went 75 miles when the car broke down. All the ring gear bolts had broken and the ring gear came off, leaving me with no brakes and unable to go forward. I've been very careful about torqueing to 35 lbs. since then and have had no more trouble - Ed
It's my understanding that torque value is with an 8 inch wrench if it matters.
"A torque wrench is a calibrated tool for applying a known amount of load to a bolt or nut. The amount of torque applied depends on the force you apply on the tool handle and the length of the wrench (torque = force x length).
For example, if your torque wrench is one foot long and you apply 30 pounds of force on the handle, you are applying 30 ft. lbs. of torque on the fastener you are tightening. If your torque wrench that is two feet long, and you apply the same 30 pounds of force on the handle, the longer tool will increase the leverage effect and multiply torque, applying 60 ft. lbs. of torque to the fastener.
A torque wrench indicates how much force you are applying to a fastener with a deflection beam or a calibrated spring mechanism. A scale or display on the tool shows you the load that is being applied. The scale may be calibrated in foot-pounds (ft. lbs.), inch-pounds (in. lbs.) or Newton-meters (Nm). A typical automotive torque wrench will have a scale that reads up to about 200 to 250 ft. lbs. (or 150 to 200 Nm).
Torque values for fasteners with wrench head sizes of 1/2 inch (12 mm) or larger are usually specified in foot-pounds (English) or Newton meters (metric). Torque values for smaller fasteners (wrench size less than 1/2 inch or 12 mm) are usually specified in inch-pounds. Typically, torque wrenches with a 1/2 inch drive will have a dual scale that shows the reading in both ft.lbs and Nm. Torque wrenches with a 3/8 or 1/4 inch drive will be for light loads and calibrated in in-.lbs."
(Message edited by Jtt3 on August 16, 2017)
(Message edited by Jtt3 on August 16, 2017)
Hi John.....I think you have had too much HOT COFFEE. "See name bar"
Your explanation of the torque wrench is spot on but I feel that your 2nd paragraph ( For example) is lacking one thing. A torque wrench is set at the desired force or tension setting for that particular wrench and bolt/nut, If you were not strong enough and you extended the deflection beam it wouldn't increase the applied torque to the bolt or nut. It would just make it easier to do the job. Regards ...Neil.
Neil I'm going to think about that over a cup of Hot Coffee, maybe I need a little cream with it. Ha John
Thank you Neil, I was getting worried. My trusty old Proto torque wrench has served me well. I couldn't work out how extending the handle length would upset the calibration.
Allan from down under.
My torque chart shows a lubricated grade 8 5/16-24 should be torqued to 20 ft-lb. I'm not sure how 35 ft-lbs was determined, but its not what I would torque them to.
The 2nd bolt in the picture has damaged threads- check the holes in your ring gear.
Threads in ring gear are OK, i chased them to be sure, but no apparent damage, it just stripped the threads right off the bolt.
What is the word on torquing them to 20Ftlbs like you would do with a Grade 8? I agree that 35 seems a bit excessive for a 5/16-24, but it was called out in the manual (even with a few sentences explaining that the supplied bolts were good to 60ftlbs)
FYI, i forgot to add, 4 fasteners which did not fail, i pulled and they showed signs of stretching. With a file they were hard, but not "hard" difficult to explain unless your the one doing the filing on them. I am guessing that these bolts are not TTY? They were the bolts from Chaffins. I guess i am going to give them a call tomorrow to get clarification.
John...Glad you got a Ha Ha out of my comment.
Allan...I owned and drove a heavy vehicle with alloy wheels each held on with 12 nuts and were tightened to 650 ft/lbs torque, with my 66kg weight, I had to put a pipe extension on to the torque wrench to break over the torque setting.
Do a search for "ring gear torque" and you'll get a number of really good hits. Stan Howe provides some very excellent guidance and also reinforces the 35ft/lb values, though he goes about it differently to say the least. Of all the people with experience in many dozen Ruckstells and standard rear ends, I would trust him and Glenn, the fellow who is reproducing the Ruckstell. There is no doubt that it appears that the bolt is being overtorqued at that value (exceeds chart value), however these bolts are not or should not be of the same material/heat treat as the bolts on the chart. Something went wrong, and you need to find out what...keep at it and please report back as to what Chaffin's says.
You put them in dry, right?
I got my Ruckstell ring gear bolts from Lang's and they worked fine at 35 ft-lbs. Chaffin's would also be a good source.
Do all of your set-up and checking work with old bolts, then use your brand new bolts for the final (really final) assembly.
Stephen, I assume these are our bolts as i know of no one else making them. However, the torque for a standard 5/16 -24 bolt is 27.5 Ft Lbs. Ruckstells spec was 35 Ft Lbs and used a bolt with a special heat treat to enable this torque. We use that same heat treat and have sold thousands of these bolts with no problems. Our bolts are made from 4340 Chrome Molly steel and are heat treated to C38-42. In out tests, the bolts broke between 45 Ft Lbs and 65 FT Lbs. Therefore, they should not break at 35 FT Lbs. If you send me your address i will send you a new set of bolts free of charge. Glen
Glen- one thing to clarify for folks- is the 35ft-lb a dry or lubricated torque value? As an example- the 27.5 ft-lb value you quoted above for a grade 8 bolt is, according to the info I have is for a dry torque. That value drops to 20 ft-lb for a lubricated torque- that's a 27% difference and I don't know if the Ruxtell manual clarifies that point or not.
Dan, no it does not clarify. I have always done a dry torque and have never had a problem with these bolts.
Glen and Dan are right on target at least in my experience torque values are based on clean an dry standards unless stated otherwise.
Neil, while I'm still thinking about what you commented on, coffee's getting a little cold, ha. There is so much drama going on in the forum that I try not to take anyone's stance as a personal slight. Sometimes even in the face of evidence we should be friendly and agree to disagree and still be civil. It does the hobby no good to make things personal.
I didn't see where Stephen said if he torqued them dry or lubricated. Maybe that's the problem
I have used at least six sets of Ruckstell ring gear bolts from Glen Chaffin, all torqued to 35 lbs ft and never had a problem.
Just had Stephens bolts tested. They are C40. Spec is C38-C42. Assuming the threads in the ring gear were good I suspect he torqued them wet with oil. However, the so called pulled threads were more than pulled, they were damaged and very irregular shaped. This would indicate bad threads in the ring gear. The original Ruckstell torque spec is 35 Ft Lbs and we have sold thousands of bolts that were torqued to this spec. However, it is definately pushing the envelope at this spec. At this point i would recommend 25 Ft Lbs as being more than adequate. I am sending Stephen a new free set of bolts. Glen
Just had Stephens bolts tested. They are C40. Spec is C38-C42. Assuming the threads in the ring gear were good I suspect he torqued them wet with oil. However, the so called pulled threads were more than pulled, they were damaged and very irregular shaped. This would indicate bad threads in the ring gear. The original Ruckstell torque spec is 35 Ft Lbs and we have sold thousands of bolts that were torqued to this spec. However, it is definately pushing the envelope at this spec. At this point i would recommend 25 Ft Lbs as being more than adequate. I am sending Stephen a new free set of bolts.
Stephen, Would you please post your address so I can send you the bolts? Glen
thank you for great supplier support to the hobby
Please note that the tips of the threads on Stephens bolts were flat indicating that they had bound up in the threads of the ring gear.
If you use an extension on that tourque wrench it will give you a faulty reading.
Glens bolts are A-1. I've used them in the past.
Richard, if you read Neil Martin's post above, you will see extending the length of pull on a torque wrench will not alter the settings. It will allow you to apply greater force if required, but will still allow the wrench to signal the correct setting, regardless of the length of the handle.
Allan from down under.
I'm talking about an extension between the socket and the wrench. Guess I could have clarified that a little better.
Does anyone have the contact information for Stephen Bowers? I would like to send him a new set of bolts. Glen
Hey Glen. Getting ready to put my Ruxtell together. Should I put in new bolts or use the old ones? It's richard in Tennessee.
Glen, click on his name and it will allow you to email him.
George, I e-mailed him but no reply. Guess he doesn't want a free set of bolts. Glen
STEVEN , WHERE ARE YOU? HOPE YOUR NOT FLOATING AROUND IN TEXAS OR FLORIDA. i HAVE A SET OF BOLTS FOR YOU. GLEN