wheel bearings

what type of bearing is in a 300tdi?

3 of 4 of my wheels have slight "nock" when jacked up and held at 12 and 6.

When spun there is no rumbling though.

it may well be wishfull thinking, but there wouldent happen to be a taper roller bearing in there would there? remove a split pin, bit of a tweek and all is well?

yes they are indeed taper roller bearings

Difficult to see quite how much play there really is unless you take the wheel off and take the half shaft bolts out. Pull the half shaft out a bit then see how much movement you've got. You might be surprised. You have to pull the half shaft to tighten the nuts anyway. And you'll need a 52mm socket. All the specialist Landy spares places do them.
And it's a tab washer, not a split pin.

ah, i see. thank you.
I shall have a look into it before i start buying wheel bearings etc.

when you say pull the half shaft?
i have a 2" socket is that close enough?

Once you take the wheel off, you'll see a ring of 5 (possibly 6, I can't remember) bolts. Take them out and the flange they hold is the end of the halfshaft. Once they're out just lever the flange out about an inch and you can check the bearings for play.
2" works out at 51mm so it may not do the job plus there isn't much clearance round the nut. A thick walled socket may not fit in anyway.
When you put the bolts back in, check the torque. Its lower than you think and you can easily screw the heads off the bolts.

thank you very much for your help.
i presume there is a 52mm nut on the end of the half shaft? and it is a tight fit inside the flange once the cover has been removed?