M10 Gear box (240)

[yung-gun]

I've been informed by a friend that the IS gearbox will fit the M52 engine. i was wondering by comparing write ups on the E30 that the 318 is has a selection of either the Getrag 240 or the Getrag 245. I was just wondering if anyone knew if the 240 would line up to the fly wheel and which fly wheel i should use. i know i'd need an uprated clutch as i doubt the M10 clutch would take the power of the M52

[jmc330i]

An M10 gearbox won't fit an M50/52 I think - I'm sure they fit the M30 anchors.

An M42 (318iS) box will bolt up to the M50/52. I believe people use the M20 flywheel and clutch.

[yung-gun]

Thanks for the heads up matey Perhaps i could pursuade someone with an IS who is considering an M30 swap

[jmc330i]

The bellhousing bolt pattern is obviously the same on the M40 box, and I've read of people using the M40 box on M50/52 conversions, but I wouldn't like to say how long the box will last.

[yung-gun]

There was no clear difference in the 2 resources i used to understand which gearbox was for which. If the m42 uses a Getrag 240 or 245 and the M10 is a getrag 240, then surely it would line up to an M52?

[jmc330i]

The gearboxes might be similar internally, but the bellhousing bolt patterns differ.

The E30 325i and E34 535i both use a getrag 260, but the boxes aren't interchangeable. If that was the case, the deviants who fit M30s in their cars could just use the M20 box, rather than M30.

In some cases, like M20 to M50, the bellhousing bolt pattern is the same, but the angle of the bolt pattern differs, so the M20 box will be rotated slightly when fitted to an M50 - the E30 320i uses a getrag 240 and will fit an M50 in this way. The M42 (as you say, also a getrag 240) happens to share the same angle as the M50 engines, so bolts straight up.

The M10 and M30 share the same bolt pattern, but this differs from the rest of the range.