s10 blast diffs

[cheapskate]

my s10's diffs are in a pretty bad way, what are people using to shim them up?
i managed to strip my spur gear as well- thought i hadnt meshed the pinion properly but looks like the shaft that carries the spur is bent
is this a common thing?

[sock dog]

hey man just run my blast and spur has half clean teeth other half worn,
looks like theres a bit of float in bearing,shaft or motor mount,
it just isnt running tru,

did someone say they run losi 22 78 spur?
direct fit?