The BMW Z3 M Coupe is an iconic classic for most BMW enthusiasts but that doesn’t mean it’s perfect. In fact, because the Z3 M’s chassis was based on that of the E36 3 Series‘, it actually had some inherent structural issues, especially when it came to more powerful versions like the Z3 M Coupe. Which is why many owners actually spend some money to have their chassis’ weaker points reinforced by independent shops, to keep things from breaking in the future. In this video from Wheeler Dealers, we get to see the chassis of a BMW Z3 M Coupe get some helpful reinforcement.
Due to the BMW Z3 M Coupe’s added torque and beefier rear diff over standard models, the rear subframe tends to fail after awhile, especially after a lot of spirited driving. Rear subframe issues are some of the most common on E36 M3s and Z3 M Coupes, due to weaknesses in the material.
To compensate for this, Wheeler Dealers’ Ant Anstead dropped the exhaust, axles, and rear differential, so he could access the rear subframe. He then removed all of the rear differential brackets completely, which required drilling out the welds and prying them off. He then made his own brackets out of steel and welded them into place. After that, he primed them, to keep them from rusting. He also added some steel to the rear anti-roll bar mounting points, to reinforce those as well.
Obviously, this isn’t a job for the average DIYer. This job requires being able to make your own metal parts, the ability to weld, and all the requisite tools. Most DIYers have neither access to such tools, nor the ability to actually do the job anyway. So most enthusiasts will have to bring their car to an independent (and reputable) shop to have this reinforcement done if they want to keep their BMW Z3 M Coupe (or E46 M3) for many more years to come. It might be an expensive job but it’s one that will give the car’s owner some much needed peace of mind.