X5 3.0i A5S390R 5L40E accumulator spring - anyone here do this?

[g300d]

So I have been getting a rough 3-4 shift. Higher the rpm, the rougher. Barely noticeable at low to mid rpm shifts.

Research shows rough shifts can be caused by a broken accumulator spring in the trans valve body. Thanks to RRPhil who tore down one of these and posted pics here and on the Range Rover forums.

I have not seen any reference of anyone doing it and posting about it though. Anyone here do a accumulator spring replacement or know of a link to someone who has posted doing it? Would like to get an idea before diving in.