BMW E46 M3 RACP Repair & Reinforcement

This 2004 BMW E46 M3 Manual Coupe with just 80k miles came to us at Redish Motorsport for the Rear Axle Carrier Panel (RACP) Repair & Reinforcement Process.
Here we document the journey by recording key stages and offering help and tips and examples to other owners and repairs who may be requiring help when carrying out this repair, or installing our very own Redish Motorsport E46 V2 RACP Reinforcement Plate Kits (available here):
redish-motorspo...
This E46 M3 had some hairline cracks inside the car in the hidden cavities of the RACP which are only found during borescope camera inspections and drilling access holes for the camera.
We had 3 spot welds and a small hairlines crack inside the rear Internal left cavity which we repaired.
Also 2 hairline cracks in each of the front Internal cavities which we also repaired and then finished by stitch welding the Rear Seat Panel to the Chassis Legs, stitch welding the RACP to the chassis legs, and stitch welding the RACP to the Rear Boot Panel, as well as replacing 4 broken spot welds in this area underneath the car.
Obviously all the spot welds and hairline cracks around the mounting points were also attended to and repaired before we installed our Redish V2 Reinforcement Plates.
This customer also specified the additional labour time to treat the corrosion on these areas we were in.
So that meant removing the redundant Battery Tray bracket, as well as temporarily removing the Fuel Tank Strap Brackets, and the Brake Pipe Brackets to get to the corrosion behind them, and blasting the brackets before coating everything in a weld-thru primer and the re-welding them to make them look as factory as possible (just with no corrosion now).
We also found and treated corrosion on the Spring Perches, Shock Turrets, RACP fuel tank contact areas, and Rear Seat Panel (this is typical on mos most E46's - you just can't see it until 1) the car is stripped down and 2) the underside is fully de-greased).
We also applied a stitch weld each side to hold the RTA Pocket to the RACP as it showed early signs or sealer-split / movement.
Then came the POR-15 Metal Prep chemical to neturalise the corrosion.
All was dried with IR lamps, then we applied Etch Primer, then High Build Primer, and then Sprayable Seam Sealer, and the a top coat colouring of our version of factory E-coat.
This came out great!
Super thin, textured, and very original looking.
Once you've watched the painted section, wind back to the start to remind yourself of the corrosion. Big difference isn't it?!
Cavity waxing was also carried out to protect the internal sections where we've carried out welding repairs. A total of 1.5 L of cavity wax is used via a 360' spray nozzle and extended wand.
Then we rebuilt the car (and used a genuine BMW Sound Deadening Pad inside the car), and carried out a full Brake Fluid Bleed, along with a 12 mile road test and a Digital Wheel Alignment.
This car also had new Genuine BMW Metal Brake Pipes front to rear and over axle with all new clips (now heavily waxed too).
Exhaust Rubber Mount & Copper Nuts
Subframe Bush Heatshield and Bolts
Eibach Camber Arms
Rear Trailing Arm Lower Ball Joints
Rear Anti Roll Bar Drop Links
Rear Xenon Drop Link
Front Steering Tie Roads
Purple Tag Refurbished Steering Rack
Then an extensive in house vehicle clean including inside and out using only detailing type products from cleanyourcar.co.uk and carried out by James Redish.
For more info on our work:
www.redish-motorsport.com
redishmotorsport
/ redishmotorsport
Instagram: Redish_Motorsport
Thanks for watching.
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[@brenrowe2042]

It would be could if with the consent of the owner you included a price breakdown of all the works completed. All of us who are watching these very specific videos are watching for a reason, we want to know what was done, how it was done and most importantly, how much it cost all in to be done.

[@sociopathicnarcissist8810]

It's strikes me as extraordinary that the owners don't have you strip and refinish all of the suspension components and drive train as well. While the corrosion on the components is seemingly cosmetic, it would make sense to me to refinish the components while they are off the car.

[@RedishMotorsportbmw]

Sociopathic Narcissist Hi, yeah sometimes there is enough in the budget to do the axle components too, and sometimes not. Thanks for the comment, James 😃👍

[@soplim8632]

I actually learned a lot from this video. Especially being an owner a e46 M3. Now I’m scared to look

[@AlexP-yb7gh]

Does anyone know of a shop like this in the America ? ?

[@reallyhappenings5597]

Ultimate Rusting Machine

[@dany_6513]

Outstanding! Masterpiece work. If you are kind...can you tell me please what kind of drill do you use and machine to get down the rust pieces?

[@davyboy888]

Fantastic vids you guys produce, really love them. Truly amazing work you've done here. The standard is at the level of racing car prep. As a rough estimate, how much would a job like this work out at cost-wise. The problems at the rear end of these E46 M3s are sending the fear of god through me about buying one. So much is hidden - making it really difficult for potential purchasers... and I'm worried I could end up with something similar to the one you showed in one of the earlier vids that was so bad it had to be scrapped.

[@Genesislights]

I was in a similar situation few months back, wondering what would it take to get this things done. From what I gathered, to do just the sub frame reinforcement alone would be around $1-1.5K complete with plates, this is probably the best scenario depending on the damage. While you are in there, replacing bushings and rubbers would make sense as well. These are probably around $1k just for parts alone and this is not including any paint job like powder coating. If I can guess, a complete restoration for a clean/non damage sub frame with all new bushings would be around $3K with parts. Redish is doing fantastic job and this is the type of work where you do not want to get the lowest bidder.

[@chrisc_m3414]

What kind of degreaser are you using? Its insane how you able to clean years of dirt and grease. Are you using a power washer or damp microfider to remove the degreaser after?

[@brucerobertson5919]

Like watching a horror film - strangely compelling. My one is same age here in NZ, looks like new underneath and never been touched. We don't do salted roads. Top job on this anyway, would have been headed to the scrap heap soon without this attention.

[@brianrasmussen2956]

Thanks for sharing, good stuff :-)

[@stevejones3938]

What sort of price would you be looking at for this sort of job? Cheers Steve

[@bauerjack1978]

Whats the paint code for that under body protection?

[@anders949494]

that car has been driven all year around in the UK right? winter salt and stuff, for seems bad with rust

[@RedishMotorsportbmw]

AndersDog94 Hi, it's hard to say for sure but yes I would imagine it's been driving during the winters too. Road salt in the UK isn't the world in the world but it doesn't do the cars any good whatsoever underneath. James 😃👍

[@d913y]

@@RedishMotorsportbmw any recommendations for prevention with the salt?

[@wot48320]

Nice work! but the constant moving camera left me dizzy.

[@brandonhunter2760]

You keep saying, “80k miles” as to suggest that every car will have issues regardless of mileage, yet this car is a rust bucket, dirt ball and grease catcher. It has obviously been used and abused. The underneath of my car looks brand new. It has been garaged and babied. This thing is a corroded mess. No wonder it’s falling apart. I think that should be noted.

[@ahm3d718]

can you just not zoom in waaaaaaaaaaaaaaaaay too muuch, or just show us an overall view every once in a while

[@I53-624]

Is it necessary to use red heat lamps for the prep