Baby BMW Forum banner

BMW Performance rear brakes hub swap?

8K views 56 replies 12 participants last post by  Mike_RS 
#1 ·
I'm looking for a set of BMW Performance callipers for the 125i and I know the rears can be problematic getting these installed and working in an OEM fashion :?

I've looked at various threads for information and I've not seen anybody get these installed yet, It seems the only definite way to get the rears installed is to swap the hubs over to 135i ones, so I'm going to start a list of parts required to get these swapped over and I need your help choosing the right parts to do the install :)

In the diagram below can you let me know which numbers I'll need to do a hub transplant on my 125i? Will I need any parts not shown in the diagram, longer drive shafts etc.

 
#53 ·
#54 ·
Thanks to the Tyrant, I've managed to collect a set of 135i hubs so I'm all set to swap the hubs over and get the rears installed on the 125i! :spotman:

I think it should be straight forward enough (fingers crossed) if anybody was wondering what's involved in doing this you need to remove about 6-7 bolts on the wheel carriers, undo 5-6 bolts on the drive shafts, remove the centre console and release the handbrake cables, unplug the ABS sensors and then remove the entire drive shaft/ hub assembly. Not exactly a 5 min job but I think it'll be worth the hassle once them lovely performance rear callipers are installed! :D

I envy 135i owners who just undo two bolts on the calliper, pop the new calliper on and bleed the brakes! :lol2:
 
#55 ·
Glad you've got the parts now and hope all bolts on easy enough :)

Shame you weren't closer for me to pop in for look at old setup, Im sure it might be possible to do this swap without a hub change just a case of finding the right disc to suit, might not be available but when I did the M135i rear swap onto my 130i with a lot of measuring and searching I found one that did he job :)

Anyhows let us know once all bolted on :D

Ian
 
#56 ·
I didn't finish this project as I ended up buying the entire 135i instead of swapping the hubs on my 125i! :lol2:

I was completely convinced I knew how to do a successful hub swap but after the replacing ABS sensors on the 125i and now the 135i (how crap are ABS sensors!) There is one issue that's throwing a spanner in the works if anybody wanted to do this conversion. The sensors are a different design on both cars!

Appart from being different part numbers, the 125i has flat a metal ring with slats on the drive shaft and a stubby ABS sensor. The 135I had a thin "band" on the drive shaft and a pointy looking sensor. My question is can the 125i be coded to work with a 135i sensor/ drive shaft?

I accidentally fitted the wrong part number on the 125i and it sent everything haywire, the fuel gauge had a mind of its own and the dash was lit up like a christmas tree so I suspect without some changes the 135i hub conversion is dead in the water.
 
#57 ·
Does anybody know if it is possible to recode the 125i to accept the 135i ABS sensor (different part number).

I was looking to sell the 135i hubs, shafts and brakes as a ready to install package for a lucky 125i owner on here but the different ABS sensors are not going to be compatible on the 125i.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top