Rust On Wheel Hub

[ibmaxx]

There is a significant amount of rust stain on the right rear hub. All the other wheels are OK and I have snapped some photos of it -



It's unsightly and the car has only done 1200km. Something is rusting big time inside but what? Any clues?

 

[Robs]

That doesn’t look right. Seems to be coming from the flat nut in the middle pic. Should have it looked at and opened up at the dealership.

 

[baabootoo]

I'd say its the steel rotor, and the rust "flung" outwards to the hole. The paint has been worn off, from the wheel, so bare metal.

 

[sean888]

There is a significant amount of rust stain on the right rear hub. All the other wheels are OK and I have snapped some photos of it -

It's unsightly and the car has only done 1200km. Something is rusting big time inside but what? Any clues?

It's not a big deal. The rust you can see is simply on the rotor hat section and it is rusting because the protective paint on the rotor hat has broken down. The screw appears to be a rotor retention screw although these are normally set further down the rotor hat behind the wheel and not all vehicles have retention screws on their brake rotors. If it is a retention screw (I am not certain) it needs to be treated because retention screws need to be removed before the rotor can be removed for machining or replacement and are a problem if they rust in place. Furthermore, where the back of the alloy wheel contacts the face of an unprotected rotor face, over time the wheel will tend to glue itself to the rotor face and if you have a flat tyre and need to put on the spare, the wheel can be very hard to remove.

If you remove the wheel you will probably find most of the rotor hat facing behind the hub section of the wheel has rust on it also which would not be unusual. Any part of a brake rotor not protected with paint and not contacted by the brake pads will get some surface rust very quickly .
You can ask the dealer if they will clean up the rust and paint the rotor hat for you under warranty but I suspect they probably won't because it is not really a significant product fault and the surface rust will not affect the performance of the brake rotor for it's normal life.

This is easy to fix yourself. Just remove the wheel and clean up the rust on the rotor hat, especially around the screw, with a small wire wheel on the end of a drill and some wet and dry sand paper. Clean the surface and paint it well with a few coats of high temp black paint.

 

[ibmaxx]

It's not a big deal. The rust you can see is simply on the rotor hat section and it is rusting because the protective paint on the rotor hat has broken down. The screw appears to be a rotor retention screw although these are normally set further down the rotor hat behind the wheel and not all vehicles have retention screws on their brake rotors. If it is a retention screw (I am not certain) it needs to be treated because retention screws need to be removed before the rotor can be removed for machining or replacement and are a problem if they rust in place. Furthermore, where the back of the alloy wheel contacts the face of an unprotected rotor face, over time the wheel will tend to glue itself to the rotor face and if you have a flat tyre and need to put on the spare, the wheel can be very hard to remove.

If you remove the wheel you will probably find most of the rotor hat facing behind the hub section of the wheel has rust on it also which would not be unusual. Any part of a brake rotor not protected with paint and not contacted by the brake pads will get some surface rust very quickly .
You can ask the dealer if they will clean up the rust and paint the rotor hat for you under warranty but I suspect they probably won't because it is not really a significant product fault and the surface rust will not affect the performance of the brake rotor for it's normal life.

This is easy to fix yourself. Just remove the wheel and clean up the rust on the rotor hat, especially around the screw, with a small wire wheel on the end of a drill and some wet and dry sand paper. Clean the surface and paint it well with a few coats of high temp black paint.

Thanks for the technical info. It turns out the screw is actually a plug made of rubber so inspections can be made. Apparently it can retain water around the plug so rust and a stain appear. I had a look at a Stinger on the showroom floor and lo and behold rust was appearing already in the same place. I fixed it by injecting rust converter in and when all dried and fixed injected aerosol grease to prevent the same happening again. You are right with the dealer not taking any action or responsibility though. I suspect a lot of others will have this trivial but unsightly problem.