Lug bolt won't torque - PeachParts Mercedes-Benz Forum

MCallahan · #1 12-31-2018, 12:21 PM

I just ordered them from McMaster-Carr, you can buy as few or as many as you like. I'd say you are looking at $25-40 to fix that, yourself. You will need to buy a tap and drill for the next size up to install, as well.

"Regarding anti-seize: it seems that I ran across this at some point. I've heard that it will interfere with torque value. Any knowledge on that?"

Common sense says a lug with proper anti-seize on it is going to torque a lot more accurately than a dry bolt in a dry hole that galls before it reaches full grip. If you ahev ever had a stainless nut gall on a stainless bolt while running it down with your fingers, this will be very clear. I have been using anti-seize on all my wheel studs adn bolts for several years now and have never had one loosen up or fall off... or gall and strip.

"FSM torque values for wheel bolts are dry values for clean, rust-free threads. If you lubricate the bolt and use the same torque value, you will be applying more clamping force. That risks damage to rims, bolts and threads. The bolts are probably 25% below their load limit at specified torque, so you may have enough reserve strength to get away with it. But it's a still a risk you need to think about. If you know the thread size, you may be able to find a table of appropriate wet torque values by internet search."

The amount of extra force applied with the anti-seize is going to be negligible, percentage wise, if in doubt, torque to the lower value of spec and it would not exceed the upper limit by more than single digits percentage in the worst case. The torque wrench could be that far off unless you have it calibrated yearly. A lot less likely to damage anything than galling, as is the case with the original issue here.

And no, don't anti-seize the tapered seat of the wheel or lug.

mmiller · #2 12-31-2018, 12:38 PM

Just an FYI to tuck away in your tool cabinet. From the Anti Seize Technology web page.

https://www.antiseize.com/PDFs/torque_specifications.pdf

mpolli · #3 12-31-2018, 12:46 PM

If the hole in the hub is stripped then you can't fix it by tapping it. If it was me I would just get another hub from a wrecking yard. Second idea would be take the hub off and take it to a machine shop for thread repair.

As far as anti-seize and torque values, the most important point is never get any anti-seize under the head of the fastener. Make sure it is just on the threads, and I tend to use it sparingly, just enough but not too much.

party · #4 12-31-2018, 12:46 PM

Quote:

Originally Posted by MCallahan

I just ordered them from McMaster-Carr, you can buy as few or as many as you like. I'd say you are looking at $25-40 to fix that, yourself. You will need to buy a tap and drill for the next size up to install, as well.

"Regarding anti-seize: it seems that I ran across this at some point. I've heard that it will interfere with torque value. Any knowledge on that?"

Common sense says a lug with proper anti-seize on it is going to torque a lot more accurately than a dry bolt in a dry hole that galls before it reaches full grip. If you ahev ever had a stainless nut gall on a stainless bolt while running it down with your fingers, this will be very clear. I have been using anti-seize on all my wheel studs adn bolts for several years now and have never had one loosen up or fall off... or gall and strip.

"FSM torque values for wheel bolts are dry values for clean, rust-free threads. If you lubricate the bolt and use the same torque value, you will be applying more clamping force. That risks damage to rims, bolts and threads. The bolts are probably 25% below their load limit at specified torque, so you may have enough reserve strength to get away with it. But it's a still a risk you need to think about. If you know the thread size, you may be able to find a table of appropriate wet torque values by internet search."

The amount of extra force applied with the anti-seize is going to be negligible, percentage wise, if in doubt, torque to the lower value of spec and it would not exceed the upper limit by more than single digits percentage in the worst case. The torque wrench could be that far off unless you have it calibrated yearly. A lot less likely to damage anything than galling, as is the case with the original issue here.

And no, don't anti-seize the tapered seat of the wheel or lug.

That is an extremely dangerous and oversimplistic conclusion. It is absolutely not common sense as you claim. Lubing threads can increase the torque readings by much more than a few percentage points. Please share where you got this information from because it's known that it can be much higher than that. Tool makers are well aware of this. It's why an impact wrench with a spec of 500 lb/ft may not be able to break a lug nut torqued to 100 lb/ft.