BMW E46 M3 - How To INSPECT for Cracks and REINFORCE your Rear Subframe 

Ooof! Sounds like a dear do! Im after buying a cabriolet next spring, excited but nervous at the same time

Thanks nick! I wanted to show it both ways so people really understand how tricky it can be to spot small cracks when they just look under the car with a flashlight

Glad you enjoyed it!

Thanks kelvin!!

Unreal right? It's a shame BMW let this go but fortunately there are things that can be done to help it live a bit longer.

Definitely. Props to the people who will do the work.

Fr I’d wanna drive there just to have them look at it if only more shops like this

You just said it they prevent it ? Lol the other stuff helps reinforce it.

What did they manage to do that made it worse? 😬

@@TR4G they welded parts of the crack, never prepped the area, and did not paint over their welds. 😩

Stay safe and look out for your parents: we are in our 70s ourselves and makes a huge difference having others help us thru

That was a solution offer if you subframe floor didn't crack yet. I would personally do it after welding reinforcement plates.

How much was it?

Thanks!

Haha close!! Evan

I believe $2k for reinforcement, $10k for floor replacement

Finding humor wherever I can get it this week...or till mid july? Yikes.

The rear subframe is mounted on a thinner sheet metal. That means it’s extremely prone to cracking due to the amount of stress and load that is directed towards those subframe mounting points as the car’s drives with its “suspension” moving up and down constantly. So no, aftermarket suspension parts aren’t what’s responsible for this common occurring problem in the E36 and E46 platforms. Literally ALL E46 models suffer from this flaw and one of the best ways to resolve this inevitable problem is through welding in those subframe reinforcement kits and reinstalling the subframe from there.

Yes

That’s probably going to be your rear trailing arm bushings. They fail and cause the vehicle to self-steer somewhat, quite unnerving if it gets bad enough.

@@Jmort93 thank you sir

All of them will have the issue

The only E46 chassis that doesn't crack is the compact. Every other cracks, but is more likely on pre facelift models with manual gearboxes.

The subframe floor is stronger on the convertible m3. If you're making high HP, I would suggest reinforcement for extra insurance.

BMW resolved the issue for most cars (excluding the M3) after march 2000. Still it is not impossible for cracks to occur in models built after that. Manuals are much more prone to this failure. A good method of preventing an e46 from cracking (again) is to install harder bearings in the rear axle carrier. This minimises possible tilting which usually weakens the subframe...

Earlier ones are worse than later. My 328ci started to crack but decided to sell and get a m240i Like the look of e46 but wouldn't sell the m240i for one now no way!

💯

The video has served its purpose 😂