Hello all. I am a new owner of a 2012 GL550 with 43k miles on it. The aluminum on the running boards looked pretty bad with yellowish stains around all the rubber protrusions. I searched around for a method of removing and cleaning them but couldn't find a reasonable solution. So the other day I messed around with them and this is what I did.

First, remove the five torx screws underneath the boards. These hold the metal to the plastic frame. Then, gently lift up on the aluminum part, maybe an inch, leaving the rubber part attached to the metal. Once the metal piece is loose, slide it forward about an inch into the front part of the running board slot. It my take a little wiggling and force to get it to move forward. With the metal part as far forward as it will go, the rear of the aluminum will be just barely free of the plastic slot and able to be pulled away and off of the vehicle.

Once removed, pop out the rubber pieces and clean with a soapy solution and stiff brush. You can treat the rubber with some silicon at this point, too. Don't mix up the rubber pieces as they need to go back just as they were removed!

On my car, under the aluminum and rubber, there was tons of dirt and sand built up on the plastic running board piece. Take the opportunity to clean off all the gunk here before reassembly.

The aluminum piece is pretty flimsy and needs to be treated with care. In order to be able to clean it thoroughly, I put it on top of about a 4 foot section of 2x4 with the lip over the side. I temporarily held it to the 2x4 by carefully putting a screw with a large plastic washer through one of the holes towards the middle.

Using bug/tar remover spray as a lubricant, I GENTLY rubbed the metal with 3M 400P wet sandpaper. This is a VERY fine sandpaper and does a great job of removing all the stains and bits of tar and dirt off the aluminum without leaving any scratches or marks. However, this method will not remove existing scratches. In doing my floorboards, I learned they are painted aluminum color, probably powder coated. I found out because on one particularly deep scratch, I tried using a more abrasive sandpaper. It removed the scratch but also removed the paint and left an unsightly shiny bare metal spot, so don't do what I did!

Reassembly is straight forward. Follow my tips and you will be rewarded with running boards that look almost as good as new!

 

I just left them in place and scrubbed with a product I found under the kitchen sink called "Bartenders Friend" which is made for cleaning stainless steel (I believe these are stainless, not aluminum.) I just wet them down, sprinkled the Bartenders Friend on there, then scrubbed with a toothbrush between the rubber nubs.

Sounds like your way works well too, perhaps good to do once every couple years, or after a really salty winter.

 

I used what amounted to rubbing compound and a bristle brush. I had to replace one of the boards as the previous owner must have worn cleats and torn the board up!

 

I use bar keepers friend at home to clean lots of kitchen gunk. Flat glass stove and stainless steel pots especially. I believe the can says not for aluminum. It has a tendency to oxidize the aluminum and turn it black(ish)

 

As the first poster mentioned the running board inserts are not bare aluminum. There is some kind of finish on them otherwise the salt and environment would tear them up.


Use caution when cleaning them up. Not advisable to use wheel cleaner and or some kind of degreaser either. If used rinse well and don't allow for it to dry on the finish.


Agree under the inserts was caked with dirt/grit a breading bed of dampness.


The inserts are easily removed for replacement and or cleaning. Mine were too far gone and needed replacement. Previous owner either played sports or was a golfer on Long Island, NY. Got the replacements online from an OEM shop in the Midwest for half what the stealer wanted locally and they came via Fed Ex Ground pretty quickly.

 

Do you have the part numbers for the metal part of the running boards? Also, how much did you end up paying?

 

so are these stainless steel or aluminium?

 

Aluminum with some type of finish to keep them from the weather. So don't scrub too hard on the finish with anything! I suspect it's baked on like powder coated. I don't think that paint would hold up to the grit on your shoes. I know it does not like golf shoes very much.


Do not use any liquid cleaner (Wheel, tire, 409, Simple Green) on them as it will hose that finish up in a heart beat. If you do, rinse very well. Rinse and repeat often.


I've seen people use wheel cleaner on them and it does a great job on hosing the finish up. The rational is leaving it on and letting it really hose the finish up therefore really killing the finish.

 

Canadian eh? I like the "hose" the finish.