kd7iwp

I am putting the exhaust back into my 535xi and in the process needed to replace two aluminum bolts that go from the bell housing to the block as they held the catalytic converter bracket. Oddly, the part number (23001222894) from realoem as well as the dealer’s system returned me a steel bolt. I’m fine with that, but now I don’t know what torque spec to use. Newtis.info only lists torque to yield values for transmission to engine bolts for the N54. Any ideas?

My transmission is the GS6-53BZ (manual)

Original aluminum on the left and new steel on the right.

Newtis instructions for N54.

kd7iwp

Well, I just made it pretty tight and called it a day. Should get the car back on the road tonight.

FormerE30Owner

I would use the 25nm value, since it is lower than what steel would be, but sufficient for this application.

kd7iwp

There's a huge difference between 25nm and 25nm +150 degrees. 25 is nothing (can easily do that with a 1/4" drive ratchet), especially on a M12x90mm bolt. I just made it really tight and called it a day.

audiophool

Torque until you can feel the threads in the block deform, then a bit less.

/s

xquatch

I just hit this same issue and BMW dealer told me to use 66NM, which is also shown in your diagram for steel bolts.

xquatch

Yikes!