TopGear Posted on Jul 23 2010, 07:34 PM
What's the difference between 1 stud and all the studs.. you just turn the hub

IOW: no that is not possible.
Unless someone cut a slot in the knuckle.
(not recommended!)

 

Exactly. That's what I thought, but several seemingly knowledgeable people have said that in the past. Don't ask me

Here, I found the post. I'm still skeptical, but it's from a reputable member, so I thought it was worth regurgitating. If my choices were ask the dealer if it was possible, or skip the track day without trying, I'd ask.: https://www.s2ki.com/forums/index.php?showt...ndpost&p=815082

And later on the same page: https://www.s2ki.com/forums/index.php?showt...ndpost&p=815152

Everything I've read tells me this shouldn't be possible, but he sounds pretty sure. (And I'm looking pretty stupid ) I'd better just shut up, because I agree with you, that it doesn't really make any sense.

 

Supposedly if its only one stud that needs to be replaced,.sometimes you can shave down a side of the lug on the back portion just enough to slide it in..i wouldnt trust it though, but it is an option

 

Is it stripped or cross-threaded? A shop f^cked up one of my studs where the lug nut would snag when 80% tight. I just cleaned up the stud with a die and the nut with a tap.

 

you might be able to fix the threads temporarily, but if it were me i wouldn't chance the strength--people have had wheels come off at the track, even with perfectly fine threads.

also, as i understand it, you can theoretically reuse your bearings if you're very careful not to damage them. i believe i've read here that some people have done just that. but if you're gonna do this, i say just be safe and do it all right the first time. when i had longer studs put in mine, i had all the bearings changed to fresh new ones.

 

The shop took the lug off and cleaned up the thread on the stud. Lug tightened down perfect.

Off to the track!

 

I waded through the previous thread and came away with two conclusions:
1) there are so many vagaries related to friction and lubrication that torque is only an approximation to the preload that is necessary for proper wheel installation - the key safety factor is that the yield strength of the lug bolt is greater than the expected load.
2) if you really want to accurately preload the lug bolts, you probably need to consider the angle-torquing method; tighten to a low torque where all slack is removed and the friction errors are minimum, then tighten a specified additional rotation angle to establish the proper preload.

Angle torquing specs are available for critical applications (e.g. aircraft engines) but might need to be experimentally developed for specific applications (e.g., S2k lugs).

So my conclusion is that if specified torquing works for you, keep using it. But if you are continually breaking lug bolts, you might want to experiment with more accurate methods of preloading the bolts.

Just my $0.02 worth.

From the earlier thread:

http://home.jtan.com/~joe/KIAT/kiat_1.htm

Excerpt:
I suspect the +/- 35% variation listed for "feel" is conservative because it is developed in a production environment in which the same wrench is used every time. Wrench type and handle length and shape change the amount of torque applied. For example, I have a 10mm sockets in 1/4, 3/8" and 1/2" drive sizes. I am sure I apply more torque when using the 1/2" drive than the 1/4" drive. It is interesting to note that using a torque wrench gives a relatively small improvement over operator "feel." However, using a torque wrench to set preload is still better than feel.
BMW and other manufacturers specify the torque of critical fasteners. BMW also publishes the DIN/ISO standard for all fasteners not specifically called out in the assembly instructions. However, Torque is a relatively poor way of generating preload because the value for K can be greatly influenced by the friction of the threads of the screw or nut on the parts and the friction of the bearing surface of the head. Friction changes with surface finish, material, hardness, and lubrication. Manufacturers are aware of this and use a safety factor when designing assemblies to account for the inconsistency in the K-value.
Attention to detail when reassembling improves the consistency of the K-value and improves the consistency of the preload generated by tightening. Threaded connections should turn freely with no binding when assembling. Test the bolt with the nut or threaded hole to make sure it turns freely. If it does not, inspect the threads for damage. (Bumps on our inclined planes reduce their efficiency.) Light damage can be cleaned up with the appropriate tap or die. Heavily damaged fasteners should be replaced. Dirt and debris in the threads can also cause them to bind. They can be cleaned with spray cleaner and compressed air. Heavily encrusted threads may have to be cleaned first with a tap, or bolt with a flat filed about 1/3 of the way across on one side.
For those readers who may doubt that there can be a +/-25% variation in preload when using a torque wrench, I have experience that shows this to be true. At work, I did an experiment where I torqued 36 screws to the point where they yielded (stretched). I assumed that the preload required to yield all screws was the same because they were from the same production lot from a reputable manufacturer. For the test, I used the same parts, the same torque wrench, the same lubrication, and the same technique. My results gave a perfectly normal distribution of torques with a standard deviation of 7.9%. This statistic indicates that 99% of the screws would yield at the mean torque value +/-23.7%, which is darn close to +/-25%.
Angle torquing is a more accurate way of preloading fasteners. The fastener is tightened to a seating torque to take up the slack and then tightened by turning it a specified number of degrees regardless of torque using a tool to measure the amount of rotation. This method is only used for certain highly loaded critical fasteners where the application warrants the extra time and expense such as with automotive head bolts sometimes use this technique. BMW uses the angle torquing method for highly stressed fasteners such as K-bike connecting rods and R11/12 cylinder heads.

 

Come on! If you going to share your knowledge make sure it valid and safe.

 

i just tighten with a calibrated torque wrench to ~90ft*lbs. i use a snapon model, and the price is totally worth it when it gives you peace of mind. i used cheapo models from sears/auto parts shops, and they've all been crap.

that said, you gotta REALLY torque super duper hard to strip those studs. maybe overuse of an impact wrench?