Hi. Need some help! My wife's 2014 2.2 Evoque has a really jerky auto box, which sometimes induces a very brief wheelspin on an upchange. I've heard this referred to as 'chuffing' on other sites.
It's going in for Diagnostic to the JLR main dealer in Chester tomorrow (£125!!!!

). They've told me that the box is a sealed unit and cannot be serviced (I smell BS...).
Can anyone offer advice on rectifying this please? And confirm the BS about the box being sealed?
TIA. Col H