Rear bumper bracket bolt specifications

[280sl1968]

Hi

Does anyone know what the specifications are for the bolts and washers etc that would have been used at the factory to fit the rear bumper brackets to the body and also the bumpers to the bracket? My existing bolts are in need of replacing but I can't tell by direct comparison with new bolts exactly what size and washer combination I should be using. If someone has the MB part numbers (if they're still available) that would be even better.

As they're out of sight, it's no big deal, but I'd like to get as close to original spec as possible.

Also, from other threads, it doesn't look as though there was ever a rubber seal or gasket between the brackets and the body. I'm tempted to make one myself because I don't like the metal against the bodywork and I think a piece of rubber would also help keep moisture out. Any reason why I shouldn't do this?


Thanks

David

[Naj ✝︎]

Hi, David,

Ordinary steel hex head bolts M10 x 30mm long (17mm head) for both bumper iron to body and bumper iron to bumper using one flat and one spring washer.

On mine, some square shims with 10mm holes were used to correct the gap between body and inner bumper edge.

Use a rubber gasket at your discretion but could it end up being a water trap?

naj

[Jonny B]

The 250/280 SL parts book I have lists the screw as DIN 000933 010035. The DIN book has 8.8 M 10 X 25 DBL 8451-21   8.8 is the strength rating, M10, and 25 mm long, (High polished galvanic iridescent passivation, standard version).

There are two washers listed

regular - 000125 010504 (I do not have a listing for this one)
lock washer - 000127 010202, DIN book says B 10 DBL 8451-11 (this is the finish, high polished, galvanized, iridescent passivation, standard version)

[114015]

John and Naj are correct about the parts, dimensions and numbers.

Only one diffence on my car.... the screws are not "high polished, galvanized, iridescent passivation, standard version" but highly brownish rusted standard version ...

Anyway,

current parts numbers are:
304017 010019 for the screw
and
912004 010102 for the lock washer.

I'm sorry that I don't have a current replacement number for the regular washer on hand.

Nevertheless, as Jonny and Naj already mentioned; these are regular norm metric screws. Any good hardware store should be able to provide (or order) them.

Good luck

Achim
(will replace these with non-original stainless ones)

[280sl1968]

Thanks guys, that's a great help.

Achim - I seem to have the same brown rusty versions as you. Maybe I will think about switching to a stainless version if it will keep the rust at bay a little bit longer.

Naj - I take your point on a gasket being a potential water trap. I would have initially thought otherwise, i.e. rubber under compression stopping water ingress, but I guess the converse is also true that it would also prevent trapped water from escaping. You guys have way more experience than me and if you are not doing it then I will leave well alone.

Thanks again

David