Vibrations

[Bens-hdi]

Hi everyone I have recently purchased a dturbo it needs tracking as the wheels are worn on the outside I'm doing that tomorrow however tonight I started getting a knocking on changing up. Also a lot of front to back vibration on the gearstick. No vibration on the steering wheel a slight knock on the suspension at times (full lock). 
I'm thinking it's possibly the rear engine mount. The rubber looks ok but I've been told they can work loose so may just need tightening. However I have read a few things where people have found it to be the driveshafts which may explain the full lock knock? Or could that be the tracking? Any common problems or ideas please people.

[Poodle]

Sounds like balljoints to me, get them checked before doing the tracking as if they're knackered it'll need tracking again once they've been replaced. I've never seen a rear engine mount work its way loose, they generally need a couple of tons of pressure to get them out. Driveshafts tend to click more than knock, and you'd be able to feel it through the steering.

[Bens-hdi]

Sounds like balljoints to me, get them checked before doing the tracking as if they're knackered it'll need tracking again once they've been replaced. I've never seen a rear engine mount work its way loose, they generally need a couple of tons of pressure to get them out. Driveshafts tend to click more than knock, and you'd be able to feel it through the steering.

There's a fair bit of movement on the driveshafts it had lower arms a while ago I'll check the ball joints cheers.

[Toms306]

Check the P bushes as well, cheap ones don't last long.

[Bens-hdi]

The drive shafts are a bit loose and knock if I shake them.

[Poodle]

From your description it does sound like the shafts are tired, if everything else is ok then that's going to be your issue. I still think it's more likely to be something suspension related though, perhaps top or lower engine mount.