What (square blind nut?) p/n goes in the sheetmetal of the rear shelf?

[Jlaa]

You are looking at a photo of the rear shelf of my car, looking up, as if your head were on the trunk floor and your face was pointed upwards.
There are four square holes --- I believe these 4 holes were designed to hold some kind of hardware to allow for attachment of brackets for a CD changer.
I would like to use these holes to attach an amplifier --- what goes inside these holes?

I have looked in the EPC round and round for any mention of CD changer brackets / blind nuts to no avail.

Many thanks

 

[2phast]

A split square insert goes in these holes, look at the second EPC picture, item 59 which is used to hold the lower trunk trim panel in place.

 

[Jlaa]

A split square insert goes in these holes, look at the second EPC picture, item 59 which is used to hold the lower trunk trim panel in place.

Thanks 2phast. I looked up the EPC - 124.990.07.92 is the square plastic "rivet" that holds the lower trunk trim panel in place - 8 per car.
Are you sure that those pieces also go in the square holes in the sheetmetal of the rear deck? Check out the following pictures - I measured the plastic rivets and the corresponding square hole in the lower trunk trim panel to be ~13.3mm. However, the opening in the sheetmetal of the rear deck is only ~11mm wide.

 

[2phast]

That plug is two piece, one goes in the hole and the other piece (the one your measuring) that inserts into the first piece, thus spreading it apart and securing it in place. You probably should take a look at the piece that actually inserts into the opening.

Of course, I can't be positive but out of the handful of cars I have parted out, there has been nothing in those holes under the rear deck and the changers I have seen were installed in their factory location in the pockets on the side of the trunk floor. The only other square holes I have seen, use these plastic, two piece plugs.

Did you pull up the changer in the EPC? The screen captures you posted don't contain the CD changer or associated brackets. I would expect there to be several brackets, one for mounting on the trunk floor and if applicable, one for under the rear deck.

 

[Jlaa]

Hmmmmm.... so far I haven't been able to find any CD changer for a w124 in the EPC.
I did find this document - SI MBNA 82/69b - which describes CD changer and bracketry for 1994+ Model years 124,129,140, and 202. However, this infers that the changers are for use with the Becker 1492, and therefore different from the changer to be used with the Becker 1432, which was used with 1992 and 1993 Model year 500Es.

SI MBNA 82/65 is supposed to describe the CD changer componentry for use with 1992/1993 models, but so far I have not been able to find that document.

 

[2phast]

That is the normal CD changer installation doc and location, right side of trunk floor. Since the 036/034 has the battery there, the location needs to be changed. It would be nice to see the corresponding CD changer document for the 036/034 though, that would answer some of the out standing questions. I think any of the 036/034 CD changer documents would be OK for reference purposes, a 92/93 specific document would mostly be identical to the 94, at least for mounting location, brackets, etc.

My specific knowledge is limited here, but I don't recall ever seeing a 036/034 changer installed under the rear deck, unless of course it was installed after-the-fact. The logical location (as to not interfere with putting items in the trunk) would be the left side trunk pocket.

Hopefully someone else can chime in and let me know if the factory installed any changers under the rear deck

 

[Jlaa]

My specific knowledge is limited here, but I don't recall ever seeing a 036/034 changer installed under the rear deck, unless of course it was installed after-the-fact. The logical location (as to not interfere with putting items in the trunk) would be the left side trunk pocket.

Hmmm. I have seen threads on here where members with 92/93 cars mention that their changers were mounted under the rear deck but ai haven’t seen any pictures.

As well, in my 93 car, the left side trunk pocket is consumed by the AMPS telephone amplifier - no room for a CD changer.

Hopefully someone else can chime in and let me know if the factory installed any changers under the rear deck

Yeah, I am curious as well.

 

[Jlaa]

OK I'm getting closer. I found this document on WIS/ASRA. First time I ever used this software. I have no idea how to export for WIS/ASRA to pdf, so I took screenshots.

• Screenshots 1 and 2 show the pedestrian w124 sedans --- changer was mounted vertically on the right side of the trunk
  • 10 CD type was the sony supplied changer
  • 6 CD type was the Alpine supplied changer with an MX3192 converter there to make the Alpine changer works w/ the Becker Grand Prix 2000.
• Screenshots 3 and 4 show the 400E / 500E --- changer was mounted under the rear deck.
  • 10 CD type was the sony supplied changer
  • 6 CD type was the Alpine supplied changer with an MX3192 converter there to make the Alpine changer works w/ the Becker Grand Prix 2000.
• Note that the bracket for the Sony changer is different than the bracket for the Alpine changer.
• Note that the Sony changer mounts with 2 screws
• Note that the Alpine changer mounts with 2 nuts

I am really curious as to how those screws/nuts fasten --- what do they fasten into / onto? Hmmmmm.

 

[2phast]

I dug through my goody box, its the box I have with all the screws, nuts, connectors etc. that I remove from cars that I have parted out. I had thought there was another white square insert that took a regular screw, but I did not find any. Only the black push pin for the square holes. I don't think these would be sufficient to hold a changer in place anyway.

There could be a snap in nut for those bolts, hard to say as none of the cars I parted out had anything in that location (otherwise I would of pried them out and kept them.)

 

[Jlaa]

Hmmmm. I think we have to wait for someone like @Dbreid or @a777fan or @SayHey to tell us how their changer bracketry mounts to the steel rear deck.... and what kind of hardware is installed in those holes in the rear deck to allow them to mount the changers. From these two threads, we can infer they have changers.

https://www.500eboard.co/forums/ind...32-without-rewiring-anything.4521/#post-64647

https://www.500eboard.co/forums/index.php?threads/cd-changer-boxes.11443/#post-162791

 

[gsxr]

Jlaa, I'm not certain, but I have a feeling you won't like the answer... pretty likely the changer mount required drilling. This was a dealer-installed option, not a factory-installed option.

 

[speedy300dturbo]

Jlaa,

If I understand correctly, you're looking for a square piece that goes into those cutouts on the *underside* of the parcel shelf? There's nothing special about those pieces and you can get them from fastener suppliers or eBay:

https://www.mcmaster.com/nylon-nuts
http://www.fastenercomponents.com/square-head-nylon-grommet-nut-p-81.html

You press it into the hole, and when you thread a screw through it, it forces the "ears" of the clip outward.

 

[a777fan]

Hmmmm. I think we have to wait for someone like @Dbreid or @a777fan or @SayHey to tell us how their changer bracketry mounts to the steel rear deck.... and what kind of hardware is installed in those holes in the rear deck to allow them to mount the changers. From these two threads, we can infer they have changers.

https://www.500eboard.co/forums/ind...32-without-rewiring-anything.4521/#post-64647

https://www.500eboard.co/forums/index.php?threads/cd-changer-boxes.11443/#post-162791

...

Back in a jiff...

 

[a777fan]

Apologies, but i did not have time tonight to dissasemble the changer bracketry, but I did take some video to show the general location of where the changer is located in my car, and a shot of the hardware used to attach the bracket.

I’ll be out working on it tomorrow (headiner replacement and rear reading lamp install) and might have some more time for exploration if it will help.

Video showing general location:

W124 CD changer mounting location

Photo of hardware:


The changer is an alpine unit.

 

[Jlaa]

Jlaa, I'm not certain, but I have a feeling you won't like the answer... pretty likely the changer mount required drilling. This was a dealer-installed option, not a factory-installed option.

Yeah, I think you're probably right. Too bad as those four square holes look perfect. I'll have to figure out a way to use those 4 holes then.

Jlaa,

If I understand correctly, you're looking for a square piece that goes into those cutouts on the *underside* of the parcel shelf? There's nothing special about those pieces and you can get them from fastener suppliers or eBay:
https://www.mcmaster.com/nylon-nuts
http://www.fastenercomponents.com/square-head-nylon-grommet-nut-p-81.html
You press it into the hole, and when you thread a screw through it, it forces the "ears" of the clip outward.

Yes! You understand me correctly. Yeah - I was looking at McMaster carr as well but then I Thanks! I was actually looking at blind rivets from McMaster Carr as well but I'm not sure those square nylon nuts are strong enough to hang ~8 pounds of amplifier off of.
Then I thought --- why not cage-nuts like are used in rack-mounted server equipment, but then I discovered that cage-nuts are a standard sized and they are a couple mm too small for the mercedes mystery four holes.



So then I browsed back to McMaster Carr --- maybe the circular blind rivets nuts will do it .... like the "screw-to-install rivet nuts" or the "steel low-profile rivet nuts" Geesh, they remind me of drywall anchors!

Apologies, but i did not have time tonight to dissasemble the changer bracketry, but I did take some video to show the general location of where the changer is located in my car, and a shot of the hardware used to attach the bracket.

I’ll be out working on it tomorrow (headiner replacement and rear reading lamp install) and might have some more time for exploration if it will help.

Video showing general location:

W124 CD changer mounting location

Photo of hardware:
View attachment 85276

The changer is an alpine unit.

Dude thanks so much! This place is awesome and you rock! The changer is mounted much more rearward than I expected, and does not cover the forward 2 square holes at all. Based on the proximity of your mounting fasteners to the ridges in the sheetmetal of the car, I am concluding that the @gsxr is right --- the CD changer brackets were probably mounted by dealers drilling new holes in the sheetmetal. The square holes are nowhere as close to the ridges as the your mounting fasteners are.

Good luck with the headliner / C-pillar trim tomorrow, and be gentle and patient with the C-pillar trim so that you don't break off those plastic tabs, but you already knew that.

 

[a777fan]

Jlaa, indeed, the changer is mounted only on the rear half of the parcel shelf space. Directly over where your really neat manufacturers sticker is located! Gixxer is most likely correct...

 

[gerryvz]

That is the normal CD changer installation doc and location, right side of trunk floor. Since the 036/034 has the battery there, the location needs to be changed. It would be nice to see the corresponding CD changer document for the 036/034 though, that would answer some of the out standing questions. I think any of the 036/034 CD changer documents would be OK for reference purposes, a 92/93 specific document would mostly be identical to the 94, at least for mounting location, brackets, etc.

My specific knowledge is limited here, but I don't recall ever seeing a 036/034 changer installed under the rear deck, unless of course it was installed after-the-fact. The logical location (as to not interfere with putting items in the trunk) would be the left side trunk pocket.

Hopefully someone else can chime in and let me know if the factory installed any changers under the rear deck

Hmmm. I have seen threads on here where members with 92/93 cars mention that their changers were mounted under the rear deck but ai haven’t seen any pictures.

As well, in my 93 car, the left side trunk pocket is consumed by the AMPS telephone amplifier - no room for a CD changer.

Yeah, I am curious as well.

Remember, that the CD changer for both early and facelift cars was a dealer-mounted option, and did NOT come from the factory with a CD changer installed (though there was wiring from the factory to mount both a phone and a CD changer).

I just last weekend disassembled and removed a factory CD changer from underneath the rear deck of a 1994 E420. I got the bracket as well. The mounting bracket/plate was attached by four sheet-metal screws bolted into the underside of the rear deck, and these were drilled holes that the screws were screwed into, NOT NOT NOT existing factory round (or square) holes. Repeat, the changer was mounted by dealer personnel, at the time of sale, using sheet metal screws drilled into holes they put into the back deck.

I was actually going to put this CD changer (for the 1492) and bracket up for sale here on the forum. Guess I'll do that today.

I have a TSB on mounting the CD changer from MB, if anyone needs it.

Cheers,
Gerry

 

[Jlaa]

Remember, that the CD changer for both early and facelift cars was a dealer-mounted option, and did NOT come from the factory with a CD changer installed (though there was wiring from the factory to mount both a phone and a CD changer).

I just last weekend disassembled and removed a factory CD changer from underneath the rear deck of a 1994 E420. I got the bracket as well. The mounting bracket/plate was attached by four sheet-metal screws bolted into the underside of the rear deck, and these were drilled holes that the screws were screwed into, NOT NOT NOT existing factory round (or square) holes. Repeat, the changer was mounted by dealer personnel, at the time of sale, using sheet metal screws drilled into holes they put into the back deck.

Oh how disappointing! I'll just have to use the "steel low profile rivet nuts" with the existing holes then.

I have a TSB on mounting the CD changer from MB, if anyone needs it.

Do you have the TSB on mounting the CD changer for 92/93 model years? I'd like to take a look please. In post #5 I threw up the TSB for mounting the 94 model year changer, which indeed talked about drilling holes.