E30 Zone

im having problems understanding the torque convertor. is it part of the autobox?, if i have my autobox changed does this change the convertor too?

No it isn't part of the box, it is an essential part of it but isn't actually a part of it.

Cheers,

Iain T

The 'torque converter' used to be called a 'fluid flywheel' (very Daimler,check my username).It's purpose is to replace the clutch on a conventional vehicle.It works by spinning fluid(ATF) until it becomes a solid,thereby joining the driving(engine)plate to the driven(gearbox)At engine idle speed,the plates are not connected,as the engine speed is increased,the fluid is forced to engage the gearbox,giving you drive.In simple terms,a torque converter forms the clutch for an autobox.It is bolted to the engine's flywheel in the same position that a clutch is.Hope that makes sense..

Always thought torque converters are one of these brilliant inventions, so ingeniousley simple.

Whilst we're on the subject of torque convertors, anyone know whether the fluid could be changed or if they're "sealed for life"?

Just wondering as when I had my 730i (ZF 4HP22/EH 'box) I always felt it would have been better with heavier fluid in the TC (i.e. the takeup of drive would have been more efficient)

thanks guys, im having my gearbox changed and the guy had it there ready too, i was told mine had prob gone too so wanted the one with replacement, so all is well cheers.

not sure about changing the oil on it i think it uses the atf from the autobox but im no profesh