Rusty Towball

To JohnRH

I am having the same problem, what did you find to be the best solution please.

I clean any surface towball oxidisation with fine emery cloth and then spray brake cleaner to remove any residual contamination. Brake Cleaner and emery cloth bought from Tool Station, much cheaper than Halfords.

Steve

I too have the same challenge with the towball stowing upside down - any sort of cover on the ball precludes the bar from stowing away properly. 

So I take a (clean!) black dog pooh bag and place it over the ball and then secure the handles around the bottom of the coupling.  It is waterproof and keeps the ball clean and can be recycled if you want to use a clean one!! 

When away I keep the towbar "open" and then use a proper towball cover - only returning to a plastic doggie bag when the towbar is folded away for any length of time.

 I just give the towball a wipe with a dry cloth to remove any loose rust. I figure that so long as the rust is still firmly attached to the steel ball it won't contaminate the pads and hence won't be detrimental to the function of the stabiliser.

For what must be the few times I would need to do it, a longish layup, I would use a good rust protection fluid and accept I needed to give the ball a "degrease". I can't see applying or removing needs to be more than a minute or two tasks.

For the protection phase I would spray/ wipe it with Supertrol and cover with the "doggie" bag, suggested.

On needing it I would remove bag and wipe most of the Supertrol off with a bit of kitchen towel followed by a spray with brake cleaner, wipe off etc.

As said if out touring or a single trip I would not bother, but if not intending to deploy for a month I would.

Supertrol

Sorry for long link:

It must be down to the towbar's finish. My MLs oe factory towbar doesn't rust, has a yellowish anodised finish, but the detachable on the previous car used to rust if left on.

Yes, it is a surprise these retractable tow balls, where 365 days year in year out are exposed to all weathers etc are not made from a more surface corrosion resistive steel alloy.

I expect in part it is the real challenges most steels have in resisting attack from the rock salt used on the roads. Plating for corrosion protection not being ideal with the wear attrition they will have in use on the loaded surfaces.

Just a tip for anyone considering purchase of a retractable tow - hitch check the material from which it and specifically the tow ball is made. I`ve had one fitted by Merc and current by Volvo and both are "bright" with no rusting. A previous detachable towbar (Witter) used to rust in the garage let alone under the car.

@JohnRH - what worked best in the end?

My Merc W204 (2012) swing out hitch has the same problem, it's steel and it rusts like crazy and cannot be replaced.  I too have an Alko friction stabiliser so the ball needs to be 100% free from grease, paint or any rust that could contaminate the friction pads.
Anything I try to seal the ball with just channels water onto the ball when it is inverted under the cars eventually (over months). 
TIP: I use a latex glove doubled-over for short stays for a few days.
For anything more than a week in wet weather I have to fully grease the ball with bearing grease and this of course requires degreasing with solvent and rags before going anywhere near the Alko stabiliser.
My next car will not have a swing out, I will go back to a detachable swan neck for this reason.  Real shame as they are so convenient in every other respect.

To any car manufacturers out there - what is your solution to swing out hitches and friction stabilisers (virtually all braked caravans need them)?  Do you supply rust-free hitches as standard?

I also suffered from rusty ball syndrome. Now over winter I smear the ball with vasline, put on an old rubber Alko ball cover and then tape a small plastic sandwich bag over it making sure to totally cover the edge of the bag.

When touring I remove everything, give it a good clean and cover with a clean Alko ball cover. I've tended not to retract the tow hitch but leave it out for the season.

Colin