[jcdub]

I fitted 340mm front discs and 4 pot calipers to my 330e. It had standard brakes. I also went to fit twin pot 345mm discs and calipers. I removed the calipers and disc and went to fit the 345mm disc, and it wouldn't fit on over the brake drum shoes. The drum on the 345mm disc was too small to fit over the original shoes. I thought it was a straight swap?
Can anyone tell me if there are other brake discs that allow for the larger drum shoes? I really would like to fit the rear twin pot calipers.

[Jimmert]

There are two types of 345mm rear discs. The ones with ~160mm drum size and the ones with ~180 drum size. Clearly you need to get the latter one. For the front, 340mm, there is only one type.

[jcdub]

Originally Posted by Jimmert

There are two types of 345mm rear discs. The ones with ~160mm drum size and the ones with ~180 drum size. Clearly you need to get the latter one. For the front, 340mm, there is only one type.

Thanks so much got the reply. I checked real OEM. But it's only showing one m performance disc number for my chassis. But it doesn't give disc / drum dimensions..

[Jimmert]

Go to the drum shoes section, there with your chassis it should show the 185mm drum size, that’s how you know.