E46 rear subframe carrier cracks

I have a few m3's to do at the moment so I am will stick up some pics here and observations as I know a lot of people have concerns

This is the one I've just started. It a 02 manual car with 110k miles. Looks to be a well minded car

Subframe down
http://uploads.tapatalk-cdn.com/2017...002e2c9aea.jpg

Cracks can be seen already
http://uploads.tapatalk-cdn.com/2017...614fb3a3b3.jpg

http://uploads.tapatalk-cdn.com/2017...c83a88e838.jpg

http://uploads.tapatalk-cdn.com/2017...208c095579.jpg

Bottom all cleaned down

Fronts
http://uploads.tapatalk-cdn.com/2017...2727842f74.jpg

http://uploads.tapatalk-cdn.com/2017...dabe137256.jpg

Rears
http://uploads.tapatalk-cdn.com/2017...b8eab2ef13.jpg

http://uploads.tapatalk-cdn.com/2017...fa1aededb6.jpg

Left arch crack
http://uploads.tapatalk-cdn.com/2017...05ade428c8.jpg

Spot welds popped
http://uploads.tapatalk-cdn.com/2017...1d6f0147a9.jpg

http://uploads.tapatalk-cdn.com/2017...296b107d2d.jpg

This is above the rear left mount in the boot
http://uploads.tapatalk-cdn.com/2017...48517b8959.jpg

I then drilled down to the top of the 2 front mounts from under the rear seat. Most people don't appear to bother doing this but there is no point plating the car if you don't address these
http://uploads.tapatalk-cdn.com/2017...2e869cc012.jpg

Both front receivers on the front were cracked at the top
http://uploads.tapatalk-cdn.com/2017...cca621c722.jpg

http://uploads.tapatalk-cdn.com/2017...e744d67dcd.jpg

Cut out over the rear mounts also
https://uploads.tapatalk-cdn.com/201...79f44cab7f.jpg

Drilled up through the receiver to access the threads

https://uploads.tapatalk-cdn.com/201...c04024e9ce.jpg


Cleaned things up and drilled the end of the cracks
https://uploads.tapatalk-cdn.com/201...b855a4f8d1.jpg

https://uploads.tapatalk-cdn.com/201...49931c92db.jpg

https://uploads.tapatalk-cdn.com/201...d924ede416.jpg

Drilled out all the broken spot welds also. About 15 in total
https://uploads.tapatalk-cdn.com/201...e6a8c3b249.jpg

Welded up
https://uploads.tapatalk-cdn.com/201...5ddc880696.jpg

https://uploads.tapatalk-cdn.com/201...651e6b02ff.jpg

https://uploads.tapatalk-cdn.com/201...fb86cda22d.jpg

Stitch welded the arch
https://uploads.tapatalk-cdn.com/201...3e436d906a.jpg

Weld ground down. You have to resist the urge to grind it down nice and flat as you are thinning the metal out by doing that
https://uploads.tapatalk-cdn.com/201...d7cfaffa7d.jpg

This is under the top skin I cut away over the rear mounts
I drilled up through the mounts and the upper skin

You can see the hole highlighted here
https://uploads.tapatalk-cdn.com/201...8977c3b18d.jpg

In the top of the pic you can see the rear chassis leg.

It's hard to believe that bmw could be so stupid as to not tie these together
Instead the loads are transferred out to spot welds on the other panels. Also because it is so far from any fixed point it is going to flex a lot more.
It's very clear that welding on plates as per reddish etc will not help this situation. It will only kick it down the road till the whole panel pulls out of the car.

Here is a video of a boot floor on a car with 40k miles and bmw structural foam injected. It's amazing that they last as long as the do when you see this

https://www.youtube.com/watch?v=ee0VvI8SlEQ

I made up some plates to transfer the load to the chassis leg
https://uploads.tapatalk-cdn.com/201...e4b43bfffa.jpg

https://uploads.tapatalk-cdn.com/201...2bbb6130ac.jpg

Here is the top of the rear mount highlighted again. It a lot nearer to a structural point now.
This is not enough on its own as over time the flexing will fatigue around the bottom welds. It could be spread out by plating around here to spread out the load.
I'm going to use longer bolts up through the rear mount and then tie that into this area and the cage on this particular car

I'm waiting on getting some custom bolts made and the reddish plates so moved on the the rod bearings

https://uploads.tapatalk-cdn.com/201...c55f3062d3.jpg

https://uploads.tapatalk-cdn.com/201...88b46c946e.jpg

https://uploads.tapatalk-cdn.com/201...7d95cb763d.jpg

Bmw spec for oil clearence is .030-.070 so these are bang on in the middle.
https://uploads.tapatalk-cdn.com/201...3bfad40971.jpg

Top shell in place
https://uploads.tapatalk-cdn.com/201...f0664ec52a.jpg

Cap shell in and arp bolts lubed up
https://uploads.tapatalk-cdn.com/201...2e0f728664.jpg

Old shells
https://uploads.tapatalk-cdn.com/201...86e8847ec8.jpg

The car has 110 miles on it. I rand bmw and it had the rod bearing recall done at 35 k
So labour 75 k on them

This is probably the worst one. You can just see the copper showing
https://uploads.tapatalk-cdn.com/201...ca3d9254e0.jpg

I wouldn't like to see a big lot more mileage on them

Epic work Dave, I was extremely impressed when I saw it in the flesh.

Great work Dave. :D

https://uploads.tapatalk-cdn.com/201...81098e5d68.jpg
Made these up to go on top of the front and rear sockets.

https://uploads.tapatalk-cdn.com/201...1c60e4ab60.jpg

Welded in place


https://uploads.tapatalk-cdn.com/201...cc2fa70ef2.jpg
Then tied it into the reinforcement plate
The longer subframe bolts will now go up through these with a nut on top which will tie the subframe directly to these.

https://uploads.tapatalk-cdn.com/201...33a7f7389e.jpg
Reddish plates

https://uploads.tapatalk-cdn.com/201...d3cdeeb467.jpg
https://uploads.tapatalk-cdn.com/201...e82220537b.jpg
https://uploads.tapatalk-cdn.com/201...dd006c335a.jpg
https://uploads.tapatalk-cdn.com/201...dbceb88170.jpg


https://uploads.tapatalk-cdn.com/201...0010c55365.jpg
Primed and stonechip applied
https://uploads.tapatalk-cdn.com/201...fe09025c10.jpg

Great work Dave.

Is this a customers car or your own Dave?


Sent from my iPhone using Tapatalk

Quote:

---

Originally Posted by Chillipepper

Is this a customers car or your own Dave?


Sent from my iPhone using Tapatalk

---

Customers car. Have 3 of them to do together so will be great to compare.

Quote:

---

Originally Posted by DaveG

Customers car. Have 3 of them to do together so will be great to compare.

---

Will you Pm me your no Dave, Thanks


Sent from my iPhone using Tapatalk

This is the best E46 M3 rear axle carrier panel reinforcement service available in the country at this moment in time.

Not only adds the plates but addresses the root cause and is the only way to do it. Fair play Dave. I'm glad there is someone doing it properly as a service. Great to have someone upto date on the current best method whereas other places are just unwilling to accept the change from the traditional​ plating.

Quote:

---

Originally Posted by schoonerm3

This is the best E46 M3 rear axle carrier panel reinforcement service available in the country at this moment in time.

Not only adds the plates but addresses the root cause and is the only way to do it. Fair play Dave. I'm glad there is someone doing it properly as a service. Great to have someone upto date on the current best method whereas other places are just unwilling to accept the change from the traditional​ plating.

---

Thanks Marc. It's only because of people like you and me that aren't just happy with the "that's what everyone does" attitude and want to really understand what is going on so we can come up with the best way to fix things.
The whole reddish plates thing has spiralled out of control. They know what's going on but they are too far into it now to change their stance on it. Think they have done over 150 cars. Imagine all those cutomers coming back if they admitted what's going on.

I'm sure a lot of the cars that are getting plates will be fine just because these cars are not getting driven like they are supposed to be driven and a lot of them won't put up a lot of mileage at this point in their life

Thanks Marc for your very detailed posts. A real inspiration to every one

What's the craic Dave? [emoji1][emoji1][emoji1]

No end to the craic down here

https://uploads.tapatalk-cdn.com/201...a9af220048.jpg
I got some longer bolts designed and machined up to extend up above the receiver

https://uploads.tapatalk-cdn.com/201...c70c541309.jpg
This is the front mount.
The tube will fit on top and a nut will then pull all the layers and the receiver together which will be a massive improvement on the std design in which all the layers are trying to pull apart from each other.
On these cars it will be tied into the cage also.

https://uploads.tapatalk-cdn.com/201...9ec74781e7.jpg

Top quality work Dave, I know where I'd be going if I had a m3.

https://uploads.tapatalk-cdn.com/201...c255ba8efe.jpg

Rear



Panel back in
https://uploads.tapatalk-cdn.com/201...c0766c7cbc.jpg


https://uploads.tapatalk-cdn.com/201...a5131d2c9e.jpg

https://uploads.tapatalk-cdn.com/201...a9af220048.jpg
I got some longer bolts designed and machined up to extend up above the receiver

https://uploads.tapatalk-cdn.com/201...c70c541309.jpg
This is the front mount.
The tube will fit on top and a nut will then pull all the layers and the receiver together which will be a massive improvement on the std design in which all the layers are trying to pull apart from each other.
On these cars it will be tied into the cage also.

https://uploads.tapatalk-cdn.com/201...9ec74781e7.jpg


Rear end completly polybushed and adjustable camber arms back in
https://uploads.tapatalk-cdn.com/201...97b013861a.jpg

Bit behind in the updates as trying to get these cars finished

https://uploads.tapatalk-cdn.com/201...e1010feacc.jpg
Noticed a small crack in the sound deadening behind the seats. Scraped off some.
Few spot welds pulled again.

https://youtu.be/yQyviZSYQnk

This is the car stopped at idle with the handbrake on. I am just letting in and out the clutch.
Fairly scary. The owner had not noticed anything when driving.

https://uploads.tapatalk-cdn.com/201...5e99aeb27f.jpg
I cut open the panel over the rear mounts again.
Found this large crack also

https://uploads.tapatalk-cdn.com/201...9df0d75dbb.jpg

I welded in the 2 side plates again like before to see what difference it would make
I didn't do anything else or repair any of the welds or weld on the reddish plates at this stage as the car is still together and I wanted to see the difference these 2 side plates would make.

This time you can see that I'm really trying to move the boot floor. Lots of revs and being aggressive with the clutch

https://youtu.be/n_vUb6YAxeg

Plates on the bottom would have had no affect on repairing this at all.

https://uploads.tapatalk-cdn.com/201...b9b72e6141.jpg

https://uploads.tapatalk-cdn.com/201...c0a95e9d1b.jpg

https://uploads.tapatalk-cdn.com/201...5f517d8a87.jpg

https://uploads.tapatalk-cdn.com/201...7422d25ff1.jpg

Bottom is very bad also

https://uploads.tapatalk-cdn.com/201...4e9a941c4b.jpg

https://uploads.tapatalk-cdn.com/201...d989601778.jpg

https://uploads.tapatalk-cdn.com/201...4371d59fc6.jpg

https://uploads.tapatalk-cdn.com/201...167d59bf67.jpg

Cracks drilled and welded up

https://uploads.tapatalk-cdn.com/201...319db6906b.jpg

https://uploads.tapatalk-cdn.com/201...7ad5bd71eb.jpg

https://uploads.tapatalk-cdn.com/201...54d287d3b5.jpg

https://uploads.tapatalk-cdn.com/201...7043f81891.jpg

https://uploads.tapatalk-cdn.com/201...4355226b1c.jpg

Plates welded on

https://uploads.tapatalk-cdn.com/201...7befd05cb5.jpg

Mounts drilled through and tapped

https://uploads.tapatalk-cdn.com/201...fbc19830b7.jpg

https://uploads.tapatalk-cdn.com/201...9d83cdbd39.jpg

https://uploads.tapatalk-cdn.com/201...fade9a50c9.jpg

https://uploads.tapatalk-cdn.com/201...51b9d5bb22.jpg

https://uploads.tapatalk-cdn.com/201...d84efda0b5.jpg

Tie in tubes welded in place.

https://uploads.tapatalk-cdn.com/201...0e56cb350c.jpg

Some more bolts machined up