I've refilled my 722.9's from a modified garden sprayer, I think it was $12 from Tractor supply. You just need a fitting to screw into the fill hole of the transmission and a 1/4 shut off valve to precisely control the delivery of the fluid. For the fitting I just drilled out a bolt, cut the head off and attached the hose from the sprayer to the end of the bolt.

Filling the transmission from the bottom using pressure is sure a lot easier than from the top with ill fitting funnels. Next time I do a 722.6 fluid change I'm going to try to fill it from the bottom.

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