If you want to carry out fixes on your own Honda Shadow Slasher 400 then it will always be a good plan to own a Workshop Manual to keep just for reference if you need to know easy methods to strip off a certain part including Gearbox and fit it again adequately.
Honda Shadow Slasher 400 Workshop Manuals will provide you with detailed diagnostic info on your car so if something is broken it helps you identify what the problem is and tips on how to fix it. After that you can determine if this can be done by yourself or if the job is simply too big you can still book your Shadow Slasher 400 in to a decent garage.
Honda Shadow Slasher 400 manual