Hi All,
I have put the 90 into daily commuting use, however I have noticed a really annoying vibration/wobble through the steering wheel between 60-70 mph. I have checked the basics to ensure nothing is loose and it all looks ok, could it be the steering damper on the way out? I am also going to get the wheels balanced just to be sure, but does anyone else have any suggestions?
Thanks,

I get same thing, at same speed. I looked and drove another defender before buying mine, and the guy told me that they get unstable at 60+ if they've got 7.50 tyres - as they are too skinny for motorway driving. Then I bought my Defender, with 7.50s from someone else later that day, and it vibrates (big time) at 60-70, so I figured this was normal! Until today, when I was searching threads here, its common but not supposed to happen ... Sorry, not a terribly helpful reply.

I don't believe that the steering damper is relevant to the problem you have. FWIW, I had a similar problem that turned out to be the Panhard rod bushes, but there are a number of potential culprits. All are easy to fix but not diagnose!

I had been battling with the same symptoms for months. There are loads of things that could cause it. On mine it turned out to be the rear diff, rear hub bearing and front swivel bearing. Often it could be multiple causes. But as yours is only 60-70 get the wheels balanced first...start with the easiest and cheapest first

I don't have a steering damper
Someone needs to wiggle the steering wheel a bit while you find/look for the fault.
Check the following
Ball joints
Steering joint
Panard rod
Swivel bushes.
A bit of play in these causes shaking.

If you are feeling it specifically through the steering wheel rather than a general vibration it will be the front axle. I would start with checking the wheel and swivel bearings. Jack one front wheel off the floor, hold it in the 12 and 6 position and rock it back and forth and repeat holding it in the 3 and 9 position. If there is movements at 3/9 it is wheel bearings, if there is movement at 12/6 it is the swivel bearings. To double check the swivel bearing play you can get an assistant to press the brakes and then any movement will be the swivel.
I would also check all of the bushes for the front axle focusing on the panhard rod and radius arms. and the ball joints on the steering arms an box. Although failing bushes/ball joints usually result in vague/odd feeling steering it may be the cause.
While you are underneath it would be worth checking the propshafts for pla as tey can cause vibrations at seed i on the way out, but not usually felt through the steering.

If none of these checks highlights anything then carefully checking the wheels for bends/buckles and getting the balanced is a good place to start.

On my 2005 110 it was the swivel preload, or lack of it, that was causing a bouncing through the steering after hitting a bump in the road at speed.

For a vibration through the steering at higher speeds l would check the front wheel balance in the first instance.

Thanks for the responses, I will investigate further.

Good news, the wheels just needed balancing. One of the front wheels had none on at all!