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BMW e46 M3 SMG to Manual Swap

The E46 SMG does well on the track for DE and Time Trials but for racing it is not quite ideal. It is streetable technology and hinders the car in various ways on the race track. Up shifting is a […]

The E46 SMG does well on the track for DE and Time Trials but for racing it is not quite ideal. It is streetable technology and hinders the car in various ways on the race track. Up shifting is a touch slow and down shifting doesn’t perfectly rev match creating a problem on trail braking and turn entry. You can overcome this somewhat by assisting rev matching by bliping the throttle but it is still not ideal. Another problem is transmission longevity. The 3rd gear syncros in the 6 speed transmissions are known to fail quickly. However, the 5 speed ZF is known to be a tough transmission and they are readily available from junk Yards. The 5 speed gear ratio’s are the exact same as the 6 speed ratios for 1st through 5th gear. Basically 6th gear is pretty much not used on the track. Some have tried to use a really short diff to utilize 6th gear but the pinion in the diff becomes too small and breaks teeth. Since 6th gear is useless it makes sense to go to a lighter, cheaper, more durable 5 Speed transmission.

So if you want to switch to a 5 speed gear box below is complete documentation on how to do this. Also note, if you are going to build a car from scratch, having the ability to include an SMG car in your donor car search is a nice option knowing the swap is easy.


  • 1 Special Notes
  • 2 Transmission/Clutch/Driveshaft
  • 3 Shifter Parts
  • 4 Clutch Pedal and Hydraulics
  • 5 Recommended Replacement Parts
  • 6Electrical
  • 7 Pictures

Special Notes

  • Parts such as the clutch disk and shift lever can be different depending on your needs but the general information is logged in the tables below.
  • You will need to weld a rear shift carrier bushing bracket to the chassis. Part (41128246251) You could actually bolt this part in if you drilled holes but some spot welding is best. Another option is to omit the bracket and bushing and use a rod end bolted to the chassis with an adapter sleeve to mate the rod end to the shift carrier.
  • You will need to trim the clutch fluid supply nipple on the brake fluid reservoir. This is simple with a pair of diagonal cutters.
  • You will have left over SMG wiring that will need to be removed. It is loomed with other engine wires so it is a pain to remove. You could get a Non SMG engine wire harness and rewire the whole engine. It is a toss up.


Part Number Qty Needed Part Description Chassis Description
22316769911 1 trans bracket e46 330 To match shorter transmission to chassis.
23001434485 1 e36 m3 transmission e36 M3 ZF 5 speed
26112229240 1 driveshaft e46 M3 lengthen front section 4″
Optional 2 gear oil N/A Gear oil of your choice
Optional 1 ECU e46 M3 You will need a non SMG ECU or have the SMG ECU modified to remove SMG programming.
21212226958 1 e36 M3 240mm clutch disc e36 M3 To match 5 speed trans splines
21512226729 1 release bearing e36 M3 Smaller bore release lever to match 5 Speed guide tube

Shifter Parts

Part Number Qty Needed Part Description Chassis Description
25117522149 1 rubber boot e46 M3 To seal around the shift lever to the transmission tunnel
25111220600 1 lever cup e46 M3 The cup for the ball of the shift lever
25111434110 1 330 shift carrier e46 330 this is from an earlier 5 speed 330
25117527255 1 shift lever e46 M3 You could use a 330 shift lever as well if desired
25111222015 1 shift carrier rear bushing e46 M3 This fits into a bracket that needs to be welded or bolted to the trans tunnel
25117507695 1 shift carrier front bushing e46 M3 The bushing is for the carrier to transmission
25117529079 1 front carrier clip e46 M3 This clip connect the shift carrier to the transmission
25117571899 2 shift rod clips e46 M3 Secures the shift rod to the shift lever and rod joint pin
25117580281 1 rod joint kit e46 M3 Connects the rod to the selector shaft of the transmission
23411466134 1 rod joint pin e46 M3 connects the rod joint to the selector shaft of the transmission
25111434116 1 330 shift rod e46 330 Connects the shifter to the rod joint/selector shaft of the transmission
optional 1 shift knob N/A Whatever factory or aftermarket shift knob you like
optional 1 shift boot N/A Whatever factory or aftermarket shift boot you like
41128246251 1 bracket for rear shift carrier bushing e46 M3 Does not exist on SMG chassis. Needs to be welded or bolted on.

Clutch Pedal and Hydraulics

Part Number Qty Needed Part Description Chassis Description
07129904567 3 Circlip e46 M3 To hold pedal onto pivoting post
35211158290 2 Bush bearing e46 M3 For pedal to pivot post
35301165321 1 return spring for clutch pedal e46 M3 to pull the clutch pedal back to top
35411113728 4 Grommet e46 M3 Fluid reservoir to clutch master supply hose through firewall grommet
35311163870 1 CLUTCH PEDAL e46 M3 The pedal itself
35311163874 1 Pin master cylinder e46 M3 To connect the pedal to the master cylinder
35211108634 1 Rubber pad e46 M3 anti slip pad on pedal surface
35316750569 1 Clutch pedal stop buffer e46 M3 to prevent pushing the clutch pedal too far. Screws into chassis weld nut.
21526773670 1 clutch master cylinder e46 M3 Main Hydraulic cylinder
07119902997 1 bolt e46 M3 To attach master cylinder to pedal assembly
07119902976 1 bolt e46 M3 To attach master cylinder to pedal assembly
07129900191 1 nut e46 M3 To attach master cylinder to pedal assembly
21521156082 1 grommet e46 M3 To close hole where clutch master goes through firewall
21521163714 1 hose e46 M3 To supply fluid from reservoir to clutch master cylinder
21526774274 1 hard clutch line e46 M3 Goes from clutch master to soft line
21521163894 1 Grommet e46 M3 Seals hard clutch line to chassis behind accelerator
21526774267 1 soft clutch line e46 M3 Goes down the firewall between the two hardlines
21522229699 1 support bracket e46 M3 Supports connect of soft line to clutch master hard line
21522229699 1 clip e46 M3 Supports connection of slave hard line to soft li
21522229675 1 hard clutch line e46 M3 From soft line to slave cylinder
21526785966 1 slave cylinder e46 M3 Hydraulics that actuate release lever
07129906196 2 slave cylinder nuts e46 M3 For slave cylinder to side of transmission

Recommended Replacement Parts

Internal Clutch Parts

Part Number Qty Needed Part Description Chassis Description
21511223328 1 release lever pin e36 M3 For release lever pivoting
21517570284 1 release lever pin clip e36 M3 Holds release lever to lever pin
21511223302 1 release lever e36 M3 Pushes the release bearing via the Slave cylinder


The SMG DME software DOES NOT look for a clutch switch input to the EWS module, it uses logic from the SMG computer. When switching to a Manual shift DME, the software DOES looks for a clutch signal from the EWS. This creates a problem since the e46 M3 SMG chassis wire harness doesn’t have the wiring that goes from the clutch pedal switch to the EWS module. Since we are talking about a racecar the best way to do this is to run a fake signal to the EWS module. You can do this by supplying +12v to Pin 8 on the EWS plug. Since there isn’t a pin or wire there, you can steal a pin out of the plugs for the SMG computer or buy a new pin from BMW and wire it yourself. The +12v supply can come from various places such as the ignition switch, power distribution block, brake switch or even a switch on the dash. The nice thing about this is you can use the starter to move the car in an emergency since you do not have to have the clutch pedal depressed.