Gearbox Issue - Service

[W12BTW]

Hi all,

i have problems with my A8 W12 2008 gearbox and hard shifting between 3rd-4th occasionally. Recently is much more prominent and started acting very weird like it doesn't know at what rpm to switch and rmp going up and down while traveling on gear. It feels like a software issue possibly due to some issue inside the gearbox. I have read a lot recently and having hard time to decide where to bring the car to be fixed. I live in London so any recommendation will be greatly appreciated.

Thanks
Jim

[H-M3]

First thing would be to plug on to VCDS to see if it throws up any errors. I can vouch for VWAudi in Harrow, speak to them too.

[johnny_quattro]

Originally Posted by W12BTW

Hi all,

i have problems with my A8 W12 2008 gearbox and hard shifting between 3rd-4th occasionally. Recently is much more prominent and started acting very weird like it doesn't know at what rpm to switch and rmp going up and down while traveling on gear. It feels like a software issue possibly due to some issue inside the gearbox. I have read a lot recently and having hard time to decide where to bring the car to be fixed. I live in London so any recommendation will be greatly appreciated.

Thanks
Jim

I'll second the advice about reading the codes with either VAGCOM/VCDS or OBDEleven dongle. I'm in Surrey and own a D2 A8L. When my gearbox went bang, KSM in Carshalton fixed it for me back in 2014. They've worked on high-end stuff like R8s and newer A8s than mine. Highly recommended.

I did have a fault a couple of years after the gearbox was reconditioned, where it went into limp mode, even whilst sitting parked up with the engine idling in Park/Neutral. Contacted KSM and they diagnosed an electronics issue of some kind - true to form, the gearbox controller or TCU had failed. Had to wait a few months and ordered a replacement from the forum sponsors. Plug and play, very simple fix for around £110.

I hope your problem is a software/sensor one - if it's a mechanical issue, then it might start to get expensive.