[Gaspo]

Hello guys!

Just replaced my lower control arms/tension struts. The funny thing I see many peoples diy saying the torque setting should be 100nm for the bolt throw the bushing . But BMW workshop manual and Bentley publisher and Haynes publisher says different. If it's a 10.9 bolt it should be 100nm and if it's a 8.8 68nm. Here comes the funny thing BMW only has one bolt according to realoem to this bushing and its 8.8. I replaced my old bolts and dident check what it was stamped on the head on the bolt. My new bolts was BMW original and sad 8.8. As I understand 10,9 and 8.8 is the type of grades of the steel. And how much you can torque it before it expand and may crack. And 8.8 is about 81nm. 10,9 about 120.

Any thoughts? :-)

[PhaseP]

When three sources say the same thing it is better to go with it.
XI models use 10.9 grade bolt there. But XI front subframe where it bolts to is steel. I think RWD front subframe is aluminum, which may be the reason for less grade bolt that require less torque.

The torque spec for the 8.9 bolt there is 68 Nm (50 ft lbs) then 90 degrees from my notes. If it is a new bolt that is, reused bolt may snap with that. It will be more than 68Nm at the end.

[Gaspo]

Originally Posted by PhaseP

When three sources say the same thing it is better to go with it.
XI models use 10.9 grade bolt there. But XI front subframe where it bolts to is steel. I think RWD front subframe is aluminum, which may be the reason for less grade bolt that require less torque.

The torque spec for the 8.9 bolt there is 68 Nm (50 ft lbs) then 90 degrees from my notes. If it is a new bolt that is, reused bolt may snap with that. It will be more than 68Nm at the end.

I saw now that X models use 10.9 thx for the info. And yes rwd subframe is aluminium at least mine was :-)