Make: BMW
Models: All E36

BMW E36 X-Brace

enlarge pictureFor improved turn-in response from your E36, few bolt-on parts are as effective as the BMW cross reinforcement (aka the x-brace) which is factory equipment on all E36 Z3, Convertibles, and the 1995 M3 Lightweight.  By bolting the subframe (which the engine is mounted atop) to the chassis, you get far less movement when the car is turned left or right.  As a added bonus, the x-brace covers the bottom of the oil pan, protecting it from curbs or other items which might otherwise damage the oil pan.  The oil drainage plug is not inhibited in any way with the addition of the x-brace. 

Most E36 M3s are ready to accept the x-brace with little fuss since the subframe already has the needed "nutserts" or "inserts" for the brace.  We have seen some early production 95 M3s that do not have the nutserts and require them to be installed.  To give you an idea if your car needs the nutserts, here's a simple chart as a guideline:

Model Year Build Date Model Nutserts Installed?
Early '95 E36 M3 Maybe
'95 to '99 E36 M3 Yes
'92 to '95 E36 318, 325 No
'96 to '99 E36 323, 328 No

You can purchase the x-brace and associated hardware from your local BMW dealer.  Here is a breakdown of parts that you will need:

Qty Part # Description List Price Each
1 # 51 71 8 410 212 Cross Reinforcement  $139.00
2 # 07 11 9 900 582 Bolt M10 x 30 $0.38
4 # 07 11 9 913 657 Bolt M8 x 25 $0.15
4 # 33 31 1 108 205 Washer $0.15
4 # 51 71 8 175 003 Nutserts (if req'd)  $0.63

If you have trouble getting to a dealer, you can purchase it direct from the following mail order outfits.  Be aware that the x-brace is rather large and may cost additional shipping charges due to it's size.

Some tools that you'll need include:

  • 13mm socket
  • 16mm socket
  • 17mm socket
  • socket driver
  • torque wrench

Installation is very straight forward.  First, you must remove the stock rear support brace (a simple bar) with the 16mm socket.  Do not be tempted to reinstall this bar in the holes located towards the rear of the car, a few inches away.  In a head-on collision, the engine is designed to move downwards, away from the interior passenger cabin.  With the x-brace AND the stock rear support brace installed, it inhibits this built in safety measure and may prevent the engine from moving downwards.

Most new E36 cars have yellowish, sticky substance called cosmoline which is sprayed to the underside of the car.  Using degreaser, clean the cosmoline from the holes and other areas where the x-brace is going to be installed.  Pre-install the x-brace loosely into position and torque according to the chart below.  If you over-tighten the M8s, you'll probably break the nutserts free (a bad thing).  If you under-tighten the bolts, they'll come lose over time.  I recommend using some Loctite 242 (blue) which is the medium strength threadlock.  Once torqued to the proper specs, the brace will never come loose.

Bolt Torque
M10 50 Nm.
M8 20 Nm

There, you've done it.  Go for a test spin around the block an notice how the slow, sharp turns will make the car feel more responsive?  Some say they feel a difference, others say it doesn't.  If BMW designed it to stiffen the more flexible chassis of a convertible, it would make sense that it would stiffen a non-convertible in the same way.

You can further enhance the x-brace by adding a UUC Motorwerks Barbarian strut tower brace to solidify the top of the chassis.  Good luck!

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