Retrofit upgraded differential in 2013 135is for 135i?

[rudyv1]

Does anyone know if the upgraded differential in the 2013is (which appeared in the 2012 model as far as I know) can be used in a regular 135i (any previous model years from 2008 to 2011) ?

Also, is this the same differential being used in the 1M?

Short Write up:

The differential in the 135is comes from a new generation of final drives optimized for running smoothness and fuel efficiency. Featuring double-helical ball bearings, the differential runs at an even lower operating temperature reached more quickly than before thanks to the reduction of fluid required in the differential. Electronic rear brake management is used to simulate a differential lock for stronger acceleration in turns and low-traction conditions.

[JasonCSU]

It is not the same rear differential that is used in the 1M. The 1M uses a traditional limited slip differential, unlike this differential whichs uses the rear brakes to simulate an LSD.

[froop]

Definitely not the same one as in the 1M. The 1M uses the same M3 limited slip differential. From that description, it seems very similar in operation to the standard open electronic differential in the older model 135i's.

[rudyv1]

is it possible to put the 1M's LSD into a regular 135i ?

I'm assuming this would require disabling the electronic signal to the differential since it doesn't have that

[Dackelone]

Originally Posted by rudyv1

Short Write up:

The differential in the 135is comes from a new generation of final drives optimized for running smoothness and fuel efficiency. Featuring double-helical ball bearings, the differential runs at an even lower operating temperature reached more quickly than before thanks to the reduction of fluid required in the differential. Electronic rear brake management is used to simulate a differential lock for stronger acceleration in turns and low-traction conditions.

Sounds like all they did was add some low friction bearings and reduced the oil capacity for the diff. Which would make it all the more important to change your diff oil - instead of BMW's "lifetime BS" policy.

BMW probably did what they did when the N55 came out. They changed the trans to slicker lower friction internals, and used less oil internally for the trans. That makes for better fuel economy. At the expense of long term life.

End result is the 2013 models probably doesn't put down power any better than a pre-2013 model would.

[GeeRam]

Originally Posted by rudyv1

is it possible to put the 1M's LSD into a regular 135i ?

Technically, yes. Wouldn't have to specifically be from a 1M though, as it's the same as the M3 one.

However, I believe, you would actually need to fit the whole rear end assembly and not just the diff unit (not sure if that includes the subframe or not) and you'd need the 1M prop to go with it.

So, technically, yes, in practical terms however........

[froop]

Originally Posted by GeeRam

Technically, yes. Wouldn't have to specifically be from a 1M though, as it's the same as the M3 one.

However, I believe, you would actually need to fit the whole rear end assembly and not just the diff unit (not sure if that includes the subframe or not) and you'd need the 1M prop to go with it.

So, technically, yes, in practical terms however........

This has been done in Australia already. M3 rear subframe + diff into a 135i.

http://www.1addicts.com/forums/showthread.php?t=748574

[TheSt|G]

M variable lock isn't a standard LSD. It is fully mechanical and uses spin pumps to transfer up to 100% of the power to either side depending on traction.

Non M cars(like a 135is) just fake it with the ediff.