Radmuttern und Kupferpaste | Posts 16+

I can confirm that there are good tire shops out there. After experiencing one for the first time in my life, because my steel rims were rusted solid in the winter. He used a crowbar to remove them, and then, using a cordless screwdriver and a plate-like attachment, he cleaned the wheel hubs until they were shiny. He then tightened the aluminum rims with an impact wrench and, finally, tightened all the screws properly by hand using a torque wrench and 100 Nm. He also advised me to lubricate the centering point on the wheel hub next winter, as it tends to rust solid there.

Bolzer wrote:

When a tire shop uses an impact wrench to tighten the bolts until water comes out, I think that's dangerous and stupid. But that's usually what happens, because of time pressure.

Hi Bolzer,

So, we once had lug nuts on our Audi that were so tightly fastened (by a really incompetent tire service) that we could only loosen them on the same day of the repair using a 1-meter extension and a strong jump. The threads survived. I find it hard to believe that 110 Nm of torque and a little grease would overstretch the screws.

What did you do when installing new wheel hubs and brake drums (if you replaced them in your workshop)? I highly doubt that any workshop removes the grease from the threads.

Hi.
It's not just about over-tightening the screws. For example, steel rims have a slight give around the screw holes to provide the screws with additional tension. If you tighten the screws too much, the rim itself will also deform and become plastically deformed (technical term). If you're putting steel rims on, pay attention when tightening them, or take a closer look at them. The screw holes are slightly recessed. It definitely takes a lot of force to over-tighten a screw, but it's possible. However, it doesn't take much to "damage" a rim. Aluminum rims are also more prone to breaking due to their material properties. With too much pressure, it's also possible for the rim to crack around the mounting holes. I haven't personally seen it, but I've heard reports from other dealers.

"When we install wheel hubs or brake drums/discs, we usually clean them with brake cleaner. However, we don't specifically clean the threads. But it's not grease, it's just a corrosion protection wax. Although, it does provide some lubrication."
It's a good idea to clean it occasionally. At the very least, you should rinse it out with brake cleaner.
Best regards, Bolzer.

Quote:

"When we install wheel hubs or brake drums/discs, we usually clean them with brake cleaner. However, we don't specifically clean the threads. But it's not grease, it's just a corrosion protection wax. It should be cleaned occasionally. At least, it should be rinsed with brake cleaner."

The brake discs are new and have a corrosion protection coating that must be removed from the braking surface after installation, for example, using brake cleaner.

I always try to avoid cleaning the area around the wheel hub, because the corrosion protection it has prevents rust from forming there for several years.

Hello there...

Please, never use this combination ever .

As mentioned above by my colleagues, the risk of detachment should not be underestimated.

I work for a company that operates across different regions, providing maintenance services, and I frequently encounter situations where bolts have sheared off. We also see completely deformed steel rims, as well as aluminum rims.

So: Keep your fingers off.

Best regards, Thommi.

By the way, I've noticed that there's very little or almost nothing written about the important torque wrench here.

Just as important, especially with LM rims, is the absolutely necessary tightening after installation.

I can already hear the groans... Okay, feel free to delete the post if you want.

Best regards, Thommi.

Hello everyone,
I highly recommend applying copper grease to the threads of the wheel bolts.
It's nonsense to say that the bolts will break off.
Once the screw is tightened, the friction is determined solely by the friction between the materials, not by any lubricants. Otherwise, a vise with a lubricated spindle wouldn't grip anything. Copper paste only prevents the bolts from rusting by preventing water from entering and helps maintain the condition for which the manufacturer specified the torque. In the case of rusted screws, a kind of micro-tooth structure forms, which increases the thread friction. This generates a torque, which reduces the clamping force available to secure the connection. In extreme cases, the bolts can even loosen.

I would be cautious about applying copper paste to the conical seating surfaces of the screw (it probably won't do anything) and to the wheel hub (because copper is more noble than aluminum or steel, which can address the mentioned corrosion).

By the way, I can only support the call for using proper torque wrenches and re-tightening after a few kilometers.

I'm looking forward to the answers; it's a fascinating topic.

Hi,
Okay, I'll chime in with my two cents (or, uh, copper paste) as well.
I've been using copper paste on the wheel studs for 20 years, but I use it very sparingly.
So far, I haven't had any problems with dented steel rims, cracked aluminum rims, or wheels that are stuck fast to the hub. This is quite different from many others who don't use any corrosion protection on the hub or bolts, which often results in steel rims with winter tires being difficult or impossible to remove from the wheel hub, sometimes requiring a sledgehammer or one of the methods described here in the forum. This is especially true since car manufacturers have started to cut costs by saving a few milli-cents on the surface treatment of the wheel hubs (or perhaps they simply stopped applying corrosion protection).
I think that using a good torque wrench and (!) slightly reducing the torque specified in the instructions, due to the possibility of over-tightening the screws, is fine when using copper paste. However, you should still take the usual precautions, such as keeping the brake discs clean and not using too much of the paste. A very thin layer is sufficient.

Regards,

Olli.

Hello!

Interesting discussion, I like it. But isn't it the case that the manufacturer assumes a dry screw? That the friction of a screw (at the thread) is never calculated with any potential lubrication taken into account?

I've never actually used any special products or treatments for anything. If the threads of the screws and the surface of the hub are cleaned each time, there are no problems. Because I help older people in my family by changing their summer and winter tires, regardless of the vehicle or manufacturer, this method has never caused any problems. Except for my brother's Audi 100, which he always takes to a tire service, that car had the problems. But with his current A& model, the problems don't occur anymore.

Regards, Peter.