I have a 2010 SAN230 with the 409 engine. i done a gearbox at 160 hrs where the clutch slipped under load. this was replaced with a brand new gearbox and i was recommended to change the oil in it after the first 25 hrs then every 50. i now have problems with the new gearbox at 240 hrs (yes 80 hrs old) which first started in reverse. it felt like i hit a false neutral and sounded like the gears grinded. I didn't think too much of it as this is pretty normal on a dirt bike then pulled the rider for his last run but when i went to reverse when picking him up i was getting the same noise and actually realised there was no drive in reverse it was only slipping. i tested it out a few times and even took the throttle off the engager to ensure that it was pushing it far enough before the throttle revved up. same result. i then limped it back to the boat ramp and it is starting to sometimes make the same slipping noise for a very brief period before engaging forward gear (maybe 1/2 a second). oil is not burnt and is at the rite level. i am assuming that the gearbox will have to come out again and be taken apart. It is definitely giving me the ****s as i feel like i am just wasting money on it. Any suggestions on what it could be? Its almost making me want t trade it in on a new mastercraft. it wouldn't be such a kick in the guts if it wasn't out of warranty. the joys of second hand boats