[F10Dan]

I am stopping in from the F10 Forum (2016 528xIDrive). Recently my tie rods needed to be replaced, the whole unit, not the ends. Why? My mechanic could not get the ends to move for an alignment, even with major heat, because the aluminum ends had fused to the steel rods.

As most of the F10 and earlier cars like yours are mostly aluminum with steel nuts, bolts, screws, washers etc... I am concerned about future repairs. For instance, what will happen when I try to remove a steel bolt from a aluminum control arm years from now.

So, I am wondering if you can shed some light on what you have found to be helpful, if anything, in preventing or delaying this issue.

Do treatments like Fluid Film help at all?

[Volasko]

Fluid film would help the surface corrosion but the dissimilar metal reaction is a chemical process that happens in all metals of differing properties that are in contact with each other. The only thing I could think of was if the manufacturer created a coating to prevent this chemical reaction from happening.

[mecheng77]

Oils do help only if they don't wash off, but anti-seize is much better.

[F10Dan]

“Stress Corrosion Cracking” is when differing metals fatigue over time and exposure to a corrosive environment. I am not an engineer but am interested in learning how BMW planned to handle this in the development of our aluminum chassis cars.

When last removing my car’s underbody shields, the screws released a white dust residue which is the result of the steal screws devolving in the aluminum frame. I imagine the process is occurring throughout the car.

I put anti seize on all of these screws hoping to reduce the rate of them turning to dust. But honestly it was just a guess. Are there any automotive engineers or others knowledgeable in this area who can provide some insight?