Wheel bolt torque settings?

[MSport_Jon]

Originally Posted by darkbluemn

How much torque for studs? I remember somewhere said 15NM?

corrected at 15 ft/lbs.

[tom @ eas]

Originally Posted by darkbluemn

How much torque for studs? I remember somewhere said 15NM?

We use 15ft-lb. for setting studs. Nuts are torqued to 105ft-lb

[mlc1978]

Originally Posted by tom @ eas

We use 15ft-lb. for setting studs. Nuts are torqued to 105ft-lb

Can't argue with the expert.
I used wheel studs/nuts on racing BMWs for many years. Never had a single failure but the studs were the best available and replaced after every season. We used Loctite when setting the studs just for a little extra insurance.
Please understand that setting the stud in the hub is not what holds it all together. The five studs just need to be snugly seated in the hub. When you put those nuts on at 105ft lbs each, and properly torque the wheel, ain't nothin going nowhere except round and round.
Oh sorry, please change current auto to 2017 M3.

[Topdwnz]

I'm curious why some folks in this thread are stating it's 105 when it's really 103. Not trying to be anal about this, but the conversion of 140Nm is rounded to 103 ft/lb. Is there some BMW tech bulletin that says 105? My sense is, 103 vs 105 doesn't make much of a difference...true?

[GregW / Oregon]

Originally Posted by Topdwnz

I'm curious why some folks in this thread are stating it's 105 when it's really 103. Not trying to be anal about this, but the conversion of 140Nm is rounded to 103 ft/lb. Is there some BMW tech bulletin that says 105? My sense is, 103 vs 105 doesn't make much of a difference...true?

As you allude to, 103 vs 105 is inconsequential. Most torque wrenches cannot be set that accurately and are probably off by more than that difference. Uniformity of the bolt tightness is far more important than 2-3 lb. one way or the other.

[frankzlin79]

I have OEM wheel lock lugs on my 2018 M3. Would the torque need to be 105 ft/lb for a wheel lock lug?

[GregW / Oregon]

Originally Posted by frankzlin79

I have OEM wheel lock lugs on my 2018 M3. Would the torque need to be 105 ft/lb for a wheel lock lug?

All lugs should be consistently torqued.

[huangm3]

does anyone know what the lugbolt type is for the competition package m3 wheels? ball seat or concical ... thanks

[GregW / Oregon]

Originally Posted by huangm3

does anyone know what the lugbolt type is for the competition package m3 wheels? ball seat or concical ... thanks

Conical.

[CanAutM3]

Originally Posted by JoeFromPA

I just drove 2000 miles on my winter wheels torqued to ~85-90 lb/ft. When I went to re-torque them this morning to 105 lb/ft, I literally got no movement on the vast majority of the bolts before my torque wrench clicked over.

Just wanted to share this for those who may be concerned if they under-torqued the wheel.

I know I am replying to an old post here, but I think it is worth mentioning.

When torquing a fastener (bolt or nut), it is very important that the torque is achieved while the fastener in is motion (rotating). The reason that is, is because static friction is higher than dynamic friction. It takes more force to get an object moving from rest that it takes to sustain motion.

So it is quite possible for lugs that have been dynamically torqued at 90lb-ft to show no movement when staticaly checked at 105lb-ft. The proper way to re-torque lugs to a higher value is to first loosen them and then dynamically re-torque them to the higher value.

As a tidbit, it is also very important not to use lubricants on the treads when torquing (unless specifically mentioned in the torquing instruction) as lubricating the tread will significantly increase the fastener stretch and clamping force for a given torque value.

[///M4ster Yoda]

Originally Posted by CanAutM3

I know I am replying to an old post here, but I think it is worth mentioning.

When torquing a fastener (bolt or nut), it is very important that the torque is achieved while the fastener in is motion (rotating). The reason that is, is because static friction is higher than dynamic friction. It takes more force to get an object moving from rest that it takes to sustain motion.

So it is quite possible for lugs that have been dynamically torqued at 90lb-ft to show no movement when staticaly checked at 105lb-ft. The proper way to re-torque lugs to a higher value is to first loosen them and then dynamically re-torque them to the higher value.

As a tidbit, it is also very important not to use lubricants on the treads when torquing (unless specifically mentioned in the torquing instruction) as lubricating the tread will significantly increase the fastener stretch and clamping force for a given torque value.

It's interesting that you revived this thread as I just purchased the BMS floor jack pad adapter yesterday and was going to look here for the correct tightening specs for our wheels. I'm tired of bringing my car elsewhere to change out the winter wheels when I can do it myself in the garage.

[GregW / Oregon]

Originally Posted by CanAutM3

I know I am replying to an old post here, but I think it is worth mentioning.

When torquing a fastener (bolt or nut), it is very important that the torque is achieved while the fastener in is motion (rotating). The reason that is, is because static friction is higher than dynamic friction. It takes more force to get an object moving from rest that it takes to sustain motion.

So it is quite possible for lugs that have been dynamically torqued at 90lb-ft to show no movement when staticaly checked at 105lb-ft. The proper way to re-torque lugs to a higher value is to first loosen them and then dynamically re-torque them to the higher value.

What you say sounds logical, but this would seem to refute part of your argument: https://www.roadandtrack.com/car-cul...to-tighten-it/

[CanAutM3]

Originally Posted by GregW / Oregon

What you say sounds logical, but this would seem to refute part of your argument: https://www.roadandtrack.com/car-cul...to-tighten-it/

We are going deep in the technical stuff, I like that .

First, no, the R&T article does not refute what I am saying. In my post, I only describe torque measurement in the same direction: when the fastener is being tightened, so the point in the article regarding lower un-tightening torque is irrelevant. Where I work, we have electronic wrenches that record and log the applied torque for quality control. The device will not register a "positive" for a torque if there is no rotation. There is a reason for that .

Second, while it is true that, when tightening, a portion of the applied torque is used to stretch the bolt and when loosening, the tension in the bolt stretch helps the un-torqueing, the net result however is highly dependent on the friction level inside the thread. The phenomenon described will mostly be noticeable on a highly lubricated thread that is un-torqued almost immediately after it has been torqued. In real life conditions, the majority of the time, untightening will require more torque than the torque used when the fastener was originally tightened. Try it for yourself: using your torque wrench, try to loosen your wheel lugs without going past the torque wrench detent .