Undertray attachment parts

JINGLE · Post by **JINGLE** » Sat Feb 16, 2019 2:18 pm

I’ve had my share of undertrays

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RDFlo · Post by **RDFlo** » Mon Feb 18, 2019 5:31 pm

patriot66 wrote: ↑Thu Feb 14, 2019 5:00 pm I've just had a look on http://www.realoem.com/ and ALL undertrays from 2.0i N46, all M54 engines and N52 engines have the same part number, 51717012723. Only the S54 engined //M has a different part number. The diagram shown for all undertrays on Realoem is the same as mine and your broken one, however if you put the part number 51717012723 in on Ebay they all come up either new or secondhand as the simpler flatter version without the mouldings on the rear corners that mate up to the anti-roll bar mounts. At some point early on BMW must have simplified the design, kept the part number and not updated the diagrams
There is a brand new one on Ebay for £45 https://rover.ebay.com/rover/0/0/0?mpre ... 3197260706

That's true. I've got in touch with the local BMW dealer and they even contacted the German counterpart and yes, they only have the flat undertray these days and recommended me to get in touch with some scrapyards.
I do have a flat one, but my mechanic said it doesn’t fit and needs some further bits to attach it to the wheel arch or, as you said, mate up to the anti-roll bar mounts. Hell knows that he wasn’t specific. He’s a cracking mechanic, but I’m starting to doubt his knowledge on cosmetic issues. Would you say the flat one couldn’t be installed if the car is set up for the undertray that you and I have? Alternatively, I should get under the car and have a look at it myself.

RDFlo · Post by **RDFlo** » Mon Feb 18, 2019 5:33 pm

JINGLE wrote: ↑Sat Feb 16, 2019 2:18 pm I’ve had my share of undertrays

Why the hell are they all different!

RDFlo · Post by **RDFlo** » Mon Feb 18, 2019 5:43 pm

Help me understand something.
I think i got point 1. and 4. right, but what does point 2. and 3. connect to?

GuidoK · Post by **GuidoK** » Mon Feb 18, 2019 5:48 pm

2 and 3 connect to side plastic parts that mask up the sides of the bumper (bridge the gap between underside bumper and wheelarch).
So they screw in to the inner/under sides of part 6:

What I don't understand is why only that flat tray has a rubber lip/air dam.
Thats imho an important piece to seal up the space behind the grilles so that the air is forced through the radiator and ac condensor (those parts seal pretty good against all sides so air can't escape along that way)

And none of those undertrays is for an M bumper? (that as an additional oil cooler on the underside so I could imagine thats a bit differenty shaped regarding that air dam)

patriot66 · Post by **patriot66** » Mon Feb 18, 2019 7:04 pm

GuidoK wrote: ↑Mon Feb 18, 2019 5:48 pm 2 and 3 connect to side plastic parts that mask up the sides of the bumper (bridge the gap between underside bumper and wheelarch).
So they screw in to the inner/under sides of part 6:

What I don't understand is why only that flat tray has a rubber lip/air dam.
Thats imho an important piece to seal up the space behind the grilles so that the air is forced through the radiator and ac condensor (those parts seal pretty good against all sides so air can't escape along that way)

And none of those undertrays is for an M bumper? (that as an additional oil cooler on the underside so I could imagine thats a bit differenty shaped regarding that air dam)

This one IS for an M bumper

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Mind boggling isn't it ?

GuidoK · Post by **GuidoK** » Mon Feb 18, 2019 8:01 pm

Makes sense, that rectangle part in front is maybe to seal the oil cooler on the underside (so that air doesnt escape there and is forced through the cooler)

JINGLE · Post by **JINGLE** » Mon Feb 18, 2019 11:56 pm

Yea my photo shows the standard (on the left) the //M (at the top) and the modified //M (bottom) to fit my APR carbon splitter all together in 1 piece

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