I've had this problem of a vibration in 5th gear at around 60mph since I got the car 2 years ago its a 53 plate D4D 40,000 miles.
I have trolled the internet and this site for answers but as yet I didnt find the solution to the problem, until now, You name I had tried it.
I decided to look more at the simple answer instead of stripping the gearbox or fitting a new clutch as I had been advised.
I have uploaded the pictures of the simple fix.
I took the gear nob off and stripped out the centre consul
1st, 2nd, 3rd, 4th no problem why because on the outer cable on the right hand side, the inner cable lies at a slight angle in 1st, 2nd ,3rd and 4th, but when its in 5th the cables run parallel thus causing a very small gap between the two, hence a vibration.
As shown in the pictures I have cut a small rubber and cut a groove the same diameter as the cable , cost 10p out the stationers released the clip for the cable and place the rubber under the cable.
Replace the cable and lubricate.
refit centre console
You may find your gear selector is now a little bit tighter, but the benifits are no more annoying vibration and £600 lighter in the pocket. That would have been the cost for toyota to replace the 2 cable and the gear change as they qouted me.
I now like my rav again
Any question drop me an email
yours aye Gavin