Subframe Poll

[sp2c]

Just collected my car from ML yesterday
Monkey confirmed rear floor completely renewed by BMW
Understand work carried early 2013, but no paperwork
mileage would have been approx. 40k
Neil M just confirmed my car is 161/422
Stock OEM car
Don't know about prev. owner usage, but must have seen a track at some time

[Steve B]

#360

Subframe replaced at 69,000 miles.

Presume it'd been tracked before my purchase as it has 2 towing eyes in boot.

Stock car when I bought it.



Steve

[mick csl]

Here is mine:

- 80'000 km
- LHD
- 100% stock,(AP brakes 1000km)
- No track
- No cracks
- Preventive work done

no.157

[0836whimper]

There was a batch of them Lesa,all E46's,M3s and CSLs eventually.:hahaha:

I might extend this batch to include all E46's (edited to add, that's what you said....)

[Csl spurs]

As a good friend off James the owner off Redish Motorsport I have seen so many cars that have been checked on numerous occasions by Bmw or other independent inspections and have been given the all clear no cracks! For James then to inspect them and find cracks!
I advise anybody now that still has there original floor that hasn't been replaced under the Bmw 10 year goodwill as pretty much most cars now have passed this to get the Redish subframe reinforcement done as every car will crack it's just a matter off when!
The service at Redish Motorsport really is second to none and a full photo journal is done with every vehicle for the owner to keep for the cars records.

[NZ_M3]

I advise anybody now that still has there original floor that hasn't been replaced under the Bmw 10 year goodwill as pretty much most cars now have passed this to get the Redish subframe reinforcement done as every car will crack it's just a matter off when!

With all due respect ... I actually disagree ... In my opinion the reinforcement plates do next to nothing and it is well documented that the reinforcement plates do not work - if anything it'll cause failures elsewhere.

First and foremost you must understand the reasons for the failures. A picture speaks a thousand words in my opinion:



That picture above to me illustrates why the reinforcements plates do little to nothing to help the cracks from appearing in the first place. Essentially the cracks are appearing due to the poor stablisation of the inner mounting points and the way the spot welds are located around the structural void.

With no tie in with the chassis rails or a boxing of the mounting sections that tie the top and bottom together ... any reinforcement plate is only placing a bandaid over what is already a weak structure.

Try this simple test if you are still in doubt. Go grab a can of coke, empty it, drill straight through the middle of the can and place a bolt through it. Now proceed to manipulate the bolt in a 90 degree fashion agains the surface of the can ... Without much effort you'll rip the bolt out of the can - this people is our subframe floor in a nutshell.

Now do the same as above, but this time, cut another coke can and layer another layer over the existing can and glue the skin over this can - do the same test again - once again you'll rip the bolt out in no time (albeit probably in an area outside this other skin) - this is what the reinforcement plates do - absolutely nothing:

Here are photos of a car with the reinforcement plate welded in and shows how the loads have been transferred into other parts of the chassis:









Now do the same test again ... but this time fill the coke can with any sort of silicon you can find - let it cure overnight ... now drill a hole through it and put the bolt through and try and rip the can. I am sure you'll find it much much harder to actually rip the aluminium can (if at all).

[devam]

So how do BMW do the fix and can you tell if it has been done by looking at the car?

[Pip1968]

When all the details are down, I will use my secretarial skillz and create some sort of chart thingy :thumbs:

QUOTE=benfj180;161033]build number added............this should be interesting!

Is there a way of showing the results via a chart/graph?

[/quote]

CSLgirl, as long as it is better than your attempt to quote Benfj in an orderly manner :-D.

NZ_M3 are you sure your mate did not blow the floor due to his sub woofers and music paraphernalia (or I am looking at wires for a space shuttle here). Maybe he blew the cardboard floor following a bank raid which resulted in only coins.

Pip

[Mike RT4]

Tom,
Thanks for sharing, that explains it perfectly.

The BMW repair replaces the floor and if memory serves me correctly, they then reinforce this with the foam, as I am sure I remember seeing this listed on the invoice.

[0836whimper]

Yes, foam is listed.

Here's my eye-popping invoice :smt103

[s.mac]

So how do BMW do the fix and can you tell if it has been done by looking at the car?

Easy to tell, finished in shit undercoat

[shimmy]

Easy to tell, finished in shit undercoat

Mine was sprayed silver

[JBird]

Cracked at 30k / 9 yrs old.
Std, no mods.
Floor replaced and foam injection done.

[Pooky]

Easy to tell, finished in shit undercoat

Based on what evidence? My repair was excellent.

[J13NY S]

Had mine inspected & no signs of any cracks though it does concern me to read where some garages have misted them.

Mine is just about to turn 34K & had Intrax suspension fitted round about 21K.

Perhaps a stupid question but does the Intrax accelerate the process or does it transfer the stress elsewhere? Or make no difference?