Differential drain bolt.... And washers?

[m3f_LockDots]

A while back a member got me thinking about these.


RealOEM lists the diff as requiring both the drain/fill bolts as well as aluminum crush washers. Viewing both on ECStuning.com sparked a thought. The drain bolt has a built in O-Ring.


Was this an update to an old version that didn't have an O-Ring (requiring the use of a crush washer) or are both the crush washer and O-Ring bolt required?


Car is a 97 M3 5spd

[m3f_bmwbob89]

You should not use both. If you have the old style with the crush ring just use a new crush ring. If you have the newer style you need new plugs.

[m3f_jayjaya29]

If it has an o-ring it doesn't need a crush washer.

[m3f_LockDots]

That's what I figured. I've never seen something double sealed like realoem makes it look like before. Most likely a plug change to include an o ring. BMW probably makes more money selling a plug than a washer.

[m3f_englishtom1596q]

yup the old ones used a crush washer. new ones use a rubber seal.

[m3f_fiveightandten]

In either case, do not over-torque. People have cracked the rear covers.

[m3f_LockDots]

yup the old ones used a crush washer. new ones use a rubber seal.

Any idea when they switched over to the newer o-ring style?