there are many ways to lock a diff
you can use hot glue, epoxy to permanently lock the diff
also thread lock will work on the metal gears
if you dont want to permanently lock your diff you could use blutac, playdough or silly putty
if you want to return the diff you just need to remove the blutac and regrease
Hmmmmm, hotglue seem's like something to try, sure the plastic won't melt though? As for threadlock on the metal gear's, will loctite 262 do? though I'm not sure that loctite will work, the way loctite works is when you say screw a screw or bolt in when tightening it your squeezing the oxygen out of loctite/where it set's, where as if you just doing that on the metal gear's it might not work properly like that if you get my drift.
could you take some photo from a side on view both left and right hand sides please
I'll take some tomorrow.
have a look on your evilbay under
7.2v fast charger tamiya, 7.2v rc fast charger,
I'm assuming when you say "evilbay" you really just mean ebay, I'll have a look, that should definitely help!
hope that helps
if you want to ever change the wheels on your bycmo
you could do 12mm hex mod that way you can use any 12mm hex wheels
i.e. tamiya, hpi, kyosho ect