While travelling back down the M1 into Sydney the car developed a bad shake mainly felt through the steering for about 45 seconds. It went away and returned about two weeks going to work on the M5 lasting about the same time again. I saw the mechanic close to work telling him and he said it could be the transmission. It has 197000 kms on it and the car is in very good condition. Is this shake leading to the transmission problem. It was serviced at 178000 and they found a little metal in the pan but it has never given me any problems yet. Has anyone experience the same.

Did the little metal piece look like this:
http://i26.photobucket.com/albums/c104/spetz83/IMG_1109_zps4c0852ea.jpg

If so have a look here:
http://www.aussiemagna.com/forums/showthread.php?t=103812

Not quite sure as it was about 12 months ago. It wasn't that large, only about a third that size. Auto Mechanic told me it will need a rebuilt soon as if it pierces the filter and gets in the pump its stuffed about $1300 for that. Since it still changes nicely and not wanting to spend the money I've forgot about hoping its ok.

My old TH started having shaking issues every now and then and it turned out to be the engine mounts !

Sounds like it was the wave spring.
To be honest seeing as you have a 5 speed auto which is rare, my opinion is that you should fix it before it destroys the transmission. From other members it seems that even if the wave spring is broken not mean certain catastrophic failure, however as your auto mechanic mentioned if one of those pieces gets picked up by the oil pump that will be the end of your transmission.

I can't comment whether the shaking is related to this.

Sounds like it was the wave spring.
To be honest seeing as you have a 5 speed auto which is rare, my opinion is that you should fix it before it destroys the transmission. From other members it seems that even if the wave spring is broken not mean certain catastrophic failure, however as your auto mechanic mentioned if one of those pieces gets picked up by the oil pump that will be the end of your transmission.

I can't comment whether the shaking is related to this.

You say the 5 speed auto is rare, I thought
Most of the sports would have been auto and the rare one the manual

Yeah the sports are 5 speed but it's still a fairly rare transmission, granted the manual more so