I'm just going to get the diff upgrade off bay and get a new allenkey set and hopefully that will open up the locked cup and then I can swap over the diff as a unit rather than individual parts. Hopefully that will sort out the speed issues and the fact that the car hardly moves at all now lol. I'll let u know how I get on once I've got the part and fitted it. I'm going to get the diff sorted before I get the trans/rec set and fit those so hopefully it will be up and running with all the upgrades in a few weeks. Will I still need to tac the diff with the upgraded diff fitted? I'm asking because my esc (TEU-104BK) does not allow the car to go from forward to backwards straight away it has to stop still before the esc allows it to go into reverse would this stop the diff from messing up or should I still tac it maybe even epoxy glue it?