Hi,

Do I start looking for a new gearbox?

Car has done 150000km, last 5000 small juddering and rpm needle jumping in the 4th and 5th gear on low revs and now the transmission fail safe message starts appearing on dash. The gearbox has also went for the fail safe mode (stuck on 4th) few times.

So, is there any point of replacing only the torque converter, with oil change or do I need to go all the way and replace the whole gearbox? And if so where to source it?

Thanks in advance.

Sounds like the mechatronic unit inside the box is playing up.

When it wears out it cant keep the pressure high enough to stop the clutches slipping IIRC and causes such issues.

There is an upgraded unit to replace it that is not cheap (IIRC ££800-1000) plus all the fitting and you'd need to check the clutches out as well as they will likely have taken a lot of wear as well. FFRR MY06 facelift With TDV8 Alloys Zeros/ATR's
Mantec Sump Guard, Rigid Load liner, MY10 BT upgrade.