The e46 M3 is actually one of the most reliable cars BMW has built in the last 10 years… unless you have the SMG option on your transmission of course.
The first generation SMG (or Sequential Manual Gearbox) transmissions have not held up well over the long run and are starting to empty the pockets of their loyal owners. If you are in the market for an e46 M3, stay clear of the SMG. If you have an SMG M3, this may be what you’re in for (if you haven’t had the pleasure already).
When the e46 M3 came to market with the SMG option, it was widely understood that if there were any issues with the transmission, it would warrant replacement and that they were not to be serviced. Nor was any service attempts to be made. Being technicians/mechanics, however, it is in our blood to just fix things. Sometimes we can go to great lengths to do so.
The replacement parts are expensive, none of them can be returned, and attempts to fix a failing SMG usually wind up with the shop losing its ass and the customer about to sue. It’s quite depressing to read the trials and tribulations inflicted by our friend the SMG.
Perhaps the most common problem with the SMG will be that of the skip shift.
You’ll be driving around town, cruising along, listening to some tunes and minding your own business; everything is A-OK in your M3 world. You see this other car and decide to show them who has the horsepower.
Light turns green and you start to see his plastic horsepower machine in your rear-view until it’s time for 3rd gear to kick in. All of a sudden you slow down, he flies by, and you see a flashing “4” in front of you and a car off in the distance. FAIL.
We can fix it, but it’s not going to be cheap or easy repair. Something to think about when attempting to be king of the horsepower down the road.
(featured image courtesy of eFile989, flickr.com)