Gearbox Choice

Hello, i’m new here! Startin my first pressure washer build and i’m in search of a gear box. My setup will take a PA 3632 for $221 or the more heavy duty 3633 for $400. Im using a 18hp Duromax and TS2021 pump. Do i need to step up to the 3633 for longevity and or performance or will the 3632 work? Thanks in advance.

Looks like the TS2021 is a 5.6gpm 1450rpm pump, which is made for belt drive. If you put it on a gear box, you’ll be overworking the pump but it’ll be capable of 6.75gpm or so if my mathmatism is working properly. A bit sketchy, but that 18hp is the model number of that 440cc engine. A 429cc Kohler command is certified at 13.4hp. Running an underpowered engine would probably be fine if you don’t plan on cleaning concrete. Otherwise you’re getting into V twin territory.




I’m a big fan of “besterest” and think it should be in every murican’s lexicon. When I was down south a long time ago I loved hearing “junk n stuff” or anything + n stuff softly spoken. Hit a pothole, dang your tire is all flat n junk, or lets get the spare n stuff. Still laugh about it.

Good- better- best-besterest (in order)

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That’s a gooder’n!

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Look at hp rating on the gearbox. Find one that has a greater hp rating that way you can move it to a larger engine. If you find that you need more hp engine in the future. I’m not a big fan of belt drives myself.