Hello friend, in the mechanical gearboxes your problem is common, the boxes have some pieces called chickens These pieces are normally bronze and the work of these pieces is to stop the speed axis of the current revolution to zero so that the pinion that is in motion chin Another back of the same pinion for the reductions Your 2nd chisronizer must have spent my recommendation is to disassemble the box that is simple vast in that model and remove the chisronizers and change them all Altere as vedações anteriores e posteriores da caixa e observe os rolamentos como eles estão no momento da montagem, lava todas as peças e monta a caixa e coloque um novo petróleo 80W/90Sae, honestamente
, é fantástico