Front sub-frame mounting bolts

Blaise · Post by **Blaise** » Tue Oct 04, 2011 1:55 pm

I am bolting my car back together and need to replace the bolts that mount the front sub-frame to the car.

On the realoem diagram, it notes that two of the four bolts use wave washers and the other two standard washers. Is that really the case?

http://www.realoem.com/bmw/showparts.do ... g=31&fg=05

I would imagine that wave washers all around would be best.

Any thoughts? Minor detail, I know.

M12X60 and M12X70

Mike W. · Post by **Mike W.** » Tue Oct 04, 2011 10:37 pm

That does look odd. Typically a split washer is used against steel and wave against aluminum. My guess as to what is going on is they really use 4 of each, the split lockwasher against the bolt head and a flatwasher against the subframe.

Blaise · Post by **Blaise** » Wed Oct 05, 2011 11:54 am

Mike W. wrote:That does look odd. Typically a split washer is used against steel and wave against aluminum. My guess as to what is going on is they really use 4 of each, the split lockwasher against the bolt head and a flatwasher against the subframe.

Cool, I will go with that. Thanks