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E46 Rear Chassis/Subframe Reinforcement Kit
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Turner Motorsport - Corporate Logo
T#:91
Part#: TDR4675412
Back Ordered
Sale - Save 35% $ 193.99

This product was last offered at the strikethrough price on
06-13-2026

$ 125.49 USD
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Sale - Save 35%
$ 193.99

This product was last offered at the strikethrough price on
06-13-2026

$ 125.49 USD
Free Shipping
Updated in 2020 to provide additional reinforcement! The E46 rear driveline and suspension are very similar to that of the E36. An unfortunate side effect of this is that the E46 also shares some of the same problems as the E36. One of these problems is the rear mounting points for the subframe, which can rip out from their spots in the sheet metal. This happens because the rear differential transmits the torsional load from the engine through the subframe, then into the chassis. This constant loading and unloading weakens the sheet metal and causes it to fatigue and separate from the chassis. BMW tried to fix this problem in the E46 by placing a cross member on the front two mounting points of the subframe. This cross member keeps the front mounting points from having problems by placing the bushing and the stud in double-sheer, thus reducing the twisting action on the sheet metal. The unfortunate side effect of this is that the load from the front of the subframe now gets transmitted to the left rear of the subframe. This is where we have seen many failures of the chassis on low mileage street cars and race cars. BMW has also tried to prevent the issue by injecting foam into the open space between the underside of the chassis and the top of the trunk. This seems to work but that does not address the issues of the spot welds failing on the sheetmetal. It can also make any additional work there harder and almost impossible to weld against. Our reinforcement kit has proven over and over again to be effective and the easiest to work with in the long run.

This product reinforces the chassis sheet metal at the subframe mounting points. We do this by thickening the metal and distributing the load over a larger area. This kit will save time when repairing the chassis, and is also strongly recommended as a preventative maintenance item.

Photo Gallery: E46 Subframe Failure / Repair

Click here for installation instructions.

This item fits the following BMWs:
1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi M3
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E36, E46 Rear Shock Tower Mount Reinforcement Kit
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Turner Motorsport - Corporate Logo
T#:3440
Part#: TSU9975100
In Stock
Sale - Save 15% $ 58.99

This product was last offered at the strikethrough price on
06-13-2026

$ 50.14 USD
Free Shipping on orders $49 and up
Sale - Save 15%
$ 58.99

This product was last offered at the strikethrough price on
06-13-2026

$ 50.14 USD
Free Shipping on orders $49 and up
Made in the USA A very common weak point on the 3 series BMW is the sheetmetal of the rear shock tower. The sheetmetal here is relatively thin and very susceptible to stress and fatigue. A worn out shock will bottom-out more often and this energy is transferred through the bump stop and into the metal chassis. Stiffer shocks and shock mounts also put more stress on the sheetmetal. Factor in age, mileage, and environmental conditions and it's not a surprise that we see shock tower failures often. BMW addressed this issue with reinforcements of their own but our's are thicker for additional strength. This kit mounts on top of the shock tower and can either be bolted or welded in place. Because of the shape of the rear shock tower, these do not fit cabrio/convertible cars.

This item fits the following BMWs:
1992-1999 E36 BMW 318i 318is 318ti 323is 325i 325is 328i 328is M3 - not for convertibles
1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi M3 - not for convertibles
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E46 Front Subframe Reinforcement Kit
10X Entries Into Our F80 M3 Sweepstakes
Turner Motorsport - Corporate Logo
T#:631
Part#: TDR4675F99
In Stock
Sale - Save 77% $ 79.99

This product was last offered at the strikethrough price on
05-03-2026

$ 18.25 USD
Free Shipping on orders $49 and up
Sale - Save 77%
$ 79.99

This product was last offered at the strikethrough price on
05-03-2026

$ 18.25 USD
Free Shipping on orders $49 and up
Made in the USA The motor mount area on a subframe is one of those easily-forgotton areas that may be hiding a serious problem. The subframe on the E46 has a gusset ('ear') welded on for the motor mounts. These gussets take the stress of the motor mount as the engine torques (more upgrades = more torque = more stress). Worn motor mounts only transfer more stress to the subframe. Unfortunately, the sheetmetal will fatigue over time even though the gusset is reinforced from the factory. Check for cracks along the welds and an uneven plane from the subframe to the gusset. A total failure of the guesset will shift your engine to the side and forward, taking out many other components along the way and leading to a very costly repair.

The next time you replace the motor mounts, oil pan gasket, checking your oil pump nut, or any other time you drop the front subframe, you should install these reinforcements. This kit comes with steel reinforcing plates that are welded to the underside of the guesset as well as plates to close off the bottom of the gusset for extra strength. Instructions included.

This item fits the following BMWs:
1999-2005 E46 BMW 323i 323ci 325i 325ci 328i 328ci 330i 330ci M3
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