Terrible Vibrations, Front Wheel Options

[3SGTE]

Over the last month or so, i have noticed a clunking/knocking noise from the front passenger wheel when turning slow or parking and turning the steering wheel, but when on a long journey home tonight, i was driving at 60mph max and just taking my time, when ever i took my foot off the gas i got a really strong knocking vibration from the passenger side wheel i think and vibrating towards the middle, hard to tell as i was driving, strange thing was though, that it only happened when my foot was off the gas!!

Any ideas?? front drive shaft, or could it be something to do with the 4wd drive shaft system??

That is my best way of describing it, any questions and ill answer them best i can.

[3SGTE]

not too sure about it being a bad motor mount, the wife said the knocking felt like it was under her feet in the foot-well, (unless that is where a mount is situated). Wierd thing was it didnt do it every time!!

As for gear change it was fine, never had trouble with gears etc, i am going to change gear-box oil soon though.

How easy is it to find out if the motor mount is broken?
Im taking it to my mechanic on wednesday so hopefully he will find out pretty quick.

[DEATH]

not too sure about it being a bad motor mount, the wife said the knocking felt like it was under her feet in the foot-well, (unless that is where a mount is situated).
How easy is it to find out if the motor mount is broken?

The rear tranny mount is right there and could very well be the culprit [as said above tho these problems can be elusive].
On FWD Celicas that mount is a serious PITA to change out - I'd hate to think what it would be like with another drive shaft and whatever else running right there. But IDK cause I've never had the pleasure of working on a true GT4.