Rear End Swap

[Jlastor]

Yeah, that is the idea, simply get the entire thing out of the m3 and into my car. Ill see if the drive shaft is good. Any idea if I cant source a good original m3 drive shaft?

[prowlerflyer]

That's my plan for the future, swap in an entire M3 rear end. Should be relatively easy over a weekend. It buys you a LSD (really needed w/TS2), slightly upgraded rear brakes and stronger axles.

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[danewilson77]

E46 M3 rear diff you will need the following.

Rear subframe
Diff housing
M3 sway bar (M3 diff will hit your stock sway bar)
M3 half shafts
M3 drive shaft (are you 5 or 6 speed?)
M3 abs sensors

Basically I would go with Quaife at this point if it was me.

Dont the steptronic ZHP have a 3.64 ratio? That is another option if you don't want to spend a ton.

If you can source the right diff out of a ZHP auto or step and do the labor yourself you could do it for a couple hundred bucks. Don't be scared, diffs aren't hard until you start trying to set ring and pinion gears yourself. Which you don't have to do.

Is a rear diff swap worth the money? IMHO one of the best damn mods you can do!!! Everyone talks HP gains Hp gains but for the money you spend to get more HP an the minimal impact it provides I say rubbish. Swapping the rear end is something you can truly feel and will give you way better acceleration. Will you have fancy dyno numbers to post? No, but who cares. This is one of the next things I want to do to the e90. Like said above, we don't have the ability to drive at high speeds like the autobahn and unless you are hitting some serious speeds on track I don't see any disadvantage.

Added to DIY thread.

HTC Thunderbolt+TT

[Hornung418]

So I just found out some super information for those wishing to swap their rear end for the M3 LSD!!

The e46m unit can be re geared with Oem m division ring and pinion to 3.23 and 3.15 ratio. LSD center can be clutch type or gin visco-lok. I just built one up for turbo use (3.15 e46m clutch LSD diff). This would allow non m cars to Pnp a LSD in matching ratio to a 6500 rpm engine with a m3 rear subframe swap.

The e46m rear diff can be configured with genuine BMW parts to have a 4 bolt front flange that will mate with non m 4 bolt driveshaft 4 bolt pattern, this would allow upgrade of e46m of diff without buying a zhp 6 bolt driveshaft

Also the late model 2005/6 325ci/cabrio 6 speed SMG cars have a 4 bolt driveshaft in 6 speed length, they run a ZF 6 speed gearbox with identical length and mounting position in the body to the e46m gearbox.

So we can get the LSD from an M3, although pretty weak compared to aftermarket options, but swap the ring and pinion for a more useable ratio.

See the entire thread HERE on e46fanatics.