MrPeaski you were right. I connected the driveshaft as in the above picture- correct phasing and it seems all is well now.
Many thanks to you and MrCake for advising me. My son will be pleased that the Outback is now working correctly.
MrPeaski, I see you have an Outback Mini 2. Have you done any upgrades? If so, which ones would you say are worthwhile?
Cheers.