Bolt Help.

[leeuk93]

Hi Guys,

This bolt fell off my car yesterday,



It was very hot when I picked it up off the road and have no idea where it has come from. Nothing on my car feels to have changed since this fell off.

I'm just wondering if anyone knows what this bolt is used for.

The bolt is just under 9cm in length and roughly 1cm in circumstance at the thread.

Thanks

Lee

[gromgsxr]

think that may be a bolt that holds the gearbox to the engine or the starter motor to gearbox by the looks of it

[Jim320i]

Definitely gearbox related. Should be easy to spot where it came from when underneath there

[leeuk93]

ok thanks! will take a look this evening.

[jimbom30cab]

looks like one of the two right at the bottom on the bellhousing where is secures to the engine sump

[leeuk93]

I think there smaller than this one.

[Grrrmachine]

Don't know what E30 this came off, but I've definitely seen that size bolt on an M20 gearbox.

To refit it, you need a Torx set. That bolt is either 11mm or 12mm, but if your gearbox bolts are loose then get a 16mm as well and make sure they're all done up tight. DO NOT use a normal socket; it won't torque the nut tight enough and will just round off the head, costing you more in the long run.

[Speedtouch]

Highly unusual for a bolt with such a long thread to unwind itself.

[leeuk93]

its weird :/

[Brianmoooore]

Had an E36 M50 in a few years back where half the bolts were completely missing, a couple more were winding themselves out, and the remainder were just finger tight.
There were some recent looking pencil lines on the prop shaft either side where it comes apart, which I suspect were a clue as to the reason.