Front wheel axle rust.

[BMWED]

Hello all

Took the front wheel off during a brake flush to re-balance, and found this.

Can't figure out what happened, how did water get in there, rust is only in the spacer area. The spacer is captured between the fork leg and bearing.

Galvanic reaction?

[dirtrider]

30 minutes ago, BMWED said:

Hello all

Took the front wheel off during a brake flush to re-balance, and found this.

Can't figure out what happened, how did water get in there, rust is only in the spacer area. The spacer is captured between the fork leg and bearing.

Galvanic reaction?

 

 

 

 

Morning BMWED

 

That area is not sealed, it fits together tight but not sealed so when the axle/spacer/threads heats up it pushes the expanded air out, then when it cools again the air contracts then can suck in moisture. Or, if that area is power washed it can take in moisture.

 

The axle OD is suppose to be lightly greased with high temperature  waterproof grease  (like Optimoly TA)  when re-installed, it looks like that wasn't done at last tire change. 

 

Once that rusting starts it will keep going so maybe some good used parts from E-Bay, or at least use a rust killer to get into the metal pores & convert the deep rooted rust into an oxide.

 

Careful of that wheel speed sensor when re-installing the wheel as it is easy to damage if not careful.

[BMWED]

Thanks for the reply dirtrider.

 

Yes, I did not grease the axle during the last tire change. Didn't know about that.

I don't power wash the bike as I realize that could force water into seals etc.

That aluminum spacer is worn out where it contacts the seal, to the point of letting water into the bearing. Had to change it once already.

I am in the process of making a spacer out of stainless, which hopefully will last longer.

 

[aggieengineer]

Have you determined how wear occurred on that spacer? It seems an unlikely spot for friction.

[Beech]

When you changed the tire and did not apply grease or aluminum based neversieze to you axle did you fill the wheel bearing lip seals (both sides) with a water resistant wheel grease. This keeps the lip seal from wearing as it rubs on the axle and keeps water out. If your seals are worn as I suspect you should replace them and also check the quality of your wheel bearings by inserting a finger and rotating the inner race. Should be absolutely smooth.

[BMWED]

I always put grease on the inside lip of the seal. Problem is, the grease attracts road grit and thereby acts as grinding paste wearing away the aluminum.

It also happens on the other side. Since the axle is harder, it doesn't wear it down, only polishes it.