W123 Front Impact Strip Retainer Part #?
 

Anyone have the part number for the front impact strip retainer? It's the two plastic pieces that the rubber slides over. I have the part number for the back, it's 1238854423 but the front is different. I know it's NLA from Mercedes but I'm hoping with a part # I can track down at least a good used one.

I don't even know what it is. Ebay is one source of used parts or even new out of stock parts. It would be easier if you had the part number for the one you need.

There is a simple repair. On the plastic piece ,remove 1" of outer rib, several inches from
end ,make this area flat, pull tight, drill 4or5mm hole through plastic and bumper
install bolt, washers, lock, nut. I prefer self locking nuts. Even can do this method if
plastic broken in several pieces. Works well and is a permanent repair.

Unfortunately trying to fix the old one wasn't an option. It was broken into four parts when it came off.

A thought...take 12-32 flat head screws, washers with two flats ground in the side, put the screw in the washer, put the thinnest nut you can find on the screw and tighten it, slide the screw into the impact strip from the end, put the screw through the hole in the bumper, install a flat washer and nut.

Another idea, secure the impact strip with 3M double sided molding tape.

Thanks to Sugar Bear for giving me an idea on how to approach this. There are three issues with the plastic retainer strips. The first is that according to the parts manual they are part of the bumper itself and not sold as a separate part like the rears are (or were anyway, since all of them are NLA). Second, they get old and brittle so inevitably they snap when trying to get the impact stip off or they crack during an impact. Third, they make getting the impact strip on a real bear.

My objective was to make it easy to get the impact strip on and get cheap, easy to source parts to do it.

The final product works amazing and makes it very easy to get the impact strip on and off. It also clamps amazingly well.

Parts List:

16-GA Sheet Aluminum
1/4-20 Stainless Hurricane Bolts
1/4x1-1/2 Stainless Fender Washers
1-4 Stainless Lock Washers
1/4 Stainless Wing Nuts

The first step is to cut the aluminum into 3/4" by 9.5" strips. I have a Accucutter shear so this was easy but if you don't have a shear this may be the hardest part. One thing I did, which may not be necessary, is I radiused the ends and then sanded everything so it was slippery smooth.

https://i.imgur.com/YZDLAwsh.jpg

The next step is to take your strip and start on one side of the bumper and mark the first two holes. The first and last strips get bent a little so make sure that you mark your first hole under the side cover and then carefully bend the strip to mark the next hole.

After you mark the holes, you just drill them out in the center. I did some sanding/deburring at this step as well.

https://i.imgur.com/shUzwU7h.jpg

Then insert the hurricane bolts.

https://i.imgur.com/RH5o4Pch.jpg

You then will insert the reainter strip with the bolt into the groove in the impact strip.

https://i.imgur.com/xTjyoXXh.jpg

The sides take a small bit of finesse but I found the easiest way was to leave the retainer strip partially out and then feed that under the side cover and then move the retainer with it attached to the bumper. The nice thing about having retainer strips that only have a few attachment points is that you can move the impact strip around when it is loosely mounted.

Repeat the same process until you have done all of the attachment points. Then align the impact strip with the front license plate and you are ready to clamp it down.

https://i.imgur.com/iIU6kASh.jpg

I used wing nuts because you don't want too much pressure otherwise you will get dimples in the rubber. It also makes it much easier and faster than trying to get a ratchet into all those weird angles.

https://i.imgur.com/iWu59GQh.jpg

The end result is everything I could have asked for. Hopefully this helps some folks in the same position.

https://i.imgur.com/xLGAVZlh.jpg

Good job!

oooh! clever, i'm definitely going to use this idea, thanks!

Yeah that was a very creative solution. Nice.

One thing I didn't try was whether just using the hurricane bolts alone would be sufficient. I have a feeling that in the front it wouldn't make much difference but it probably would be a little loose on the sides in the curve. Worth a try for someone who doesn't have easy access to a shear to make the aluminum strips.

That being said, if anyone is hard up and really needs the strips, just PM me. They're real quick to make and shouldn't cost too much to ship since they'll weigh almost nothing.

I've been silent for a bit, but I've got some concerns about this proposed repair. The different materials you've used are going to cause galvanic corrosion over time and you'll be left doing this again.

Aluminum + Stainless Steel is a no-go. The Aluminum is going to corrode when moisture is present.

Stainless + Carbon steel (the back of the bumper) is a no go. The Bumper is going to start to corrode when moisture is present.

I think the solution is great, and would be perfect if the materials were changed. I'd propose a painted aluminum strip or perhaps a piece of ABS or other thermoplastic as a retainer. The addition of a rubber/plastic fender washer behind the stainless washer would insulate the bumper from the stainless hardware.

To be honest, I hadn’t given any thought to galvanic corrosion because my car is a sunny day only driver. You’re definitely right that this could be an issue for those driving in weather or even cars that aren’t garaged.

It seems like using stainless strips and then using some rubber or fiber washers on the back of the bumper would solve the issue.