m40 gearbox

[bosers]

Hi, I'm plotting my M52 conversion. Was going to use my existing running gear, 320i gearbox and prop and 3.91 lsd. I'm wondering if there's any benefit to using an M40 gearbox? Will this avoid modding the gearbox mount, does it sit at correct angle? Thinking this might be easier than the mod. Any thoughts welcomed, cheers.

[jmc330i]

Yes the M40 box will bolt up to the M52 fine and will sit at the correct angle for the standard E30 crossmember etc. If you use the M20 flywheel, you will still need the M20 starter and don't forget the spreader plate for the flywheel bolts. You may also need to change the spigot bearing in the M52 crank to suit the gearbox shaft.

There is the question of how long the M40 box will last behind an M52 though. The only experience I've had of this combo is on a mates stripped out track/drift M52 touring that's driven hard at every opportunity. So far the M40 box is taking the abuse but he does say the getrag rattle is getting worse.

[bosers]

Thanks, yeah I've got the m20 starter and fly. Reading Wiki I think if I went m40 box I might need to get an M40 prop but still looks like it might be a cheapish option as opposed to e36 box, prop and diff.

[jmc330i]

If you use the M40 box I think you can use the 320i prop, but I'm not 100%.
My mate bought his touring already converted (albeit badly) so we don't know which prop was used.

[bosers]

Thanks James, I'll think on. . .

[bimanut]

M40 box needs the 320 prop,use the 320 gear stick cradle and put a short shift stick in it

[bosers]

Sounds like a good plan! Nice one for your help guys.