vibration in fifth gear

[clairedave]

hi  all .fitted 265/85/16  on boost alloys to my 90 200tdi . but at 50 mph in fifth  now have vibration but clears at 58mph .runs fine in forth at 50-55 is it bigger tyres  or ratios  any ideas props are fine so not that

[Stephen Leckie]

My understanding - assuming that there was no vibration before changing tyres - front wheels out of balance affect the vehicle up to 60, the rear after 60.

[Range Rover Blues]

I have one the same and bigger tyres make it worse, it's the extra strain of moving them.

IIRC in 5th the props and engine are at a similar speed,also the engine has the least mechanical adbantage over the wheels, but any vibration in the pros and engine harmonise worse than in any other gear.

Thing is I know I have a V7 on a bad day, it's eating a valve and I just don't have time to fix it, when I do roll on 4.6l of John Eals engine and an auto box :twisted: