A auto not shifting into 4th.

[larry]

Hello all.
I went on the motorway with the daughter for the first time today and noticed it would happily go through 1st, 2nd and 3rd gear but not into 4th.
I remember driving it home on the motor when I brought it her and it happily went into 4th about a month ago.
As it was her first time we sat at 60mph with revs on 4,000. Even when we went to 70 to overtake it still wouldn't shift to 4th.
It sounds cruel to run it at 4,000rpm And also for fuel economy.
Luckily it's 99% city driving for her so not an issue at the moment.
The pic attached confirms my findings.
Many thanks.

 

[Mach1]

I would check the Auto box fluid level, this is typical of low fluid either from a seal leak or maybe the gearbox needs flushing and refilling with fresh hydraulic fluid, these gearboxes tend to be overlooked when serviced.