2nd hand Lazer issues

[dobber]

Just got a lazer off this forum, all seemed ok until I got the electrics in and ran it up. It sounds like a bag of nails, literally! It looks like the main issue is the spur gear. It moves/tilts front to back and has movement up to. It could probably do with shimming out but I don't have any of that size. It does sound free running with no motor on but running it with reminds me of a nitro car. Any thought, is this amount of play in the sour gear normal? It's a lazer zx5 fs2 not sp but has sp front end and the law 44 carbon top deck.

Thanks