My rear wiper stopped working the other day so I summoned up the courage to have a look and try to find the problem. To cut a long story short, once I had removed the tailgate liner panel, I was showered with rusty water which was leaking from the motor housing. I removed the motor with the gearbox attached and more rusty water ran down my knuckles. I stripped the assembly down, cleaned out all the rusty water, de-greased the housings in the sink (don't tell the Mrs), re-assembled, re-fitted and I now have a working rear wiper. I'm curious as to how all that water ended up inside the gearbox housing as there was no apparent sign of ingression, I can only guess that it ran down the wiper shaft and didn't run out again.

hi had exactly the same problem on my focus and carried out the same repair as you. i too came to the same conclusion that the water is running down the shaft, however i didnt do anything to resolve the problem. fixed mine about 3 yr ago an still working sweet as, so if it dies again i will just carry out the same repair. good fix mate!