E46 subframe differential reinforcement brace

E46 Non-M HD Differential Mount Kit

Another E46 part designed from the ground up by SLG that nobody else offers! This is for when you need the next level of protection from subframe and axle failures! 

The factory E46 differential mounting leaves so much to be desired for many reasons as explained below:

  • Power is unevenly distributed through the subframe to the vehicle floor, causing twisting and the notorious cracking of E46 subframe mounting areas
  • The diff is held with little leverage, and twists more than you think. With high power and/or clutch kicks we have seen bent front bolts and broken rear mounts in many cars
  • The moving diff contributes to blown axle CV joints aka broken axles
  • We just plain broke the rear mount on our 330. Race car problems!

So, take advantage of what is a power capable diff (up to ~450hp) and dont bother upgrading to an M3 subframe setup. Our kit bolts between the diff and the diff cover. It then attaches to the subframe via two weld-on tabs. Laser cut from steel in the USA.

Kit contents:

  1. Differential plate
  2. Two Subframe mounting tabs
  3. Two heavy duty mounting bolts
  • Remove differential from subframe, and cover from diff.
  • Install the large plate, using differential seal RTV between the diff and plate, and plate and diff cover.
  • Torque bolts to 30 ft/lbs after RTV has cured for an hour. We recommend using longer bolts to get more thread engagement and not strip the case. 30mm with a washer is ok if using stock cover.
  • Install diff back into the subframe.
  • Weld on the first mounting tab after loosely securing it to the diff plate, while the diff is still bolted to the original rear mount for placement.
  • Remove the diff and cut off the original rear mount.
  • Install the diff using the front mounts and first tab you welded on. Loosley bolt on the second tab and weld on.
  • Remove diff and finalize welding.
  • Paint, what you like, install diff, and go rip