Thaum lub sijhawm ua haujlwm ntawm lub excavator, yog tias lub gearbox mus ncig, lub tshuab yuav tsum tau nres (lossis txuas ntxiv tsav) raws sijhawm, thiab qhov ua rau yuav tsum raug txheeb xyuas thiab tshem tawm qhov txhaum. Txoj kev tshwj xeeb yog:
(1) Thaum muaj "gear hloov" thaum tsav tsheb ntawm txoj kev tiaj tus, koj tuaj yeem nres lub tshuab raws li cov lus qhia kaw, ua tib zoo tshawb xyuas qhov ua rau, thiab kho qhov teeb meem.
(2) Thaum muaj "gear dhia" thaum tsav tsheb nce toj, koj tuaj yeem teeb tsa lub iav mus rau qhov chaw qis qis lossis thawj lub iav qhov chaw, thiab nres lub tshuab thaum nws nce mus txog qhov siab ntawm txoj kab nqes los daws teeb meem; Yog hais tias lub downshifting tsis ua tiav los yog muaj lwm yam "gear jump", lub tshuab yuav tsum raug tso tseg raws li cov lus qhia thiab yuav tsum tau ntawm lub ramp shutdown, thiab ces qhov txhaum yuav tsum raug tshem tawm.
(3) Thaum muaj "gear dhia" thaum tsav tsheb ntawm txoj kab nqes nqes, lub iav yuav tsum tau hloov mus rau qhov chaw siab ceev raws li cov lus qhia rau upshifting lossis "emergency downshifting" ntsuas. Tom qab lub tshuab mus txog hauv qab ntawm txoj kab nqes, nws yuav tsum tau nres rau kev tshuaj xyuas thiab kev daws teeb meem; Yog tias "upshifting" lossis "downshifting" ua tsis tiav, lossis yog "khiav" tshwm sim dua (hauv nruab nrab iav), tus neeg tsav tsheb tuaj yeem tswj lub cav ceev ntawm qhov nruab nrab ceev (kom tiv thaiv lub cav los ntawm stalling), siv txoj kev "braking" rau xaub lub tshuab mus rau hauv qab ntawm txoj kab nqes, thiab tom qab ntawd daws teeb meem. Yog tias "upshifting" lossis "grabbing gear" ua tsis tiav, lossis yog "khiav iav" tshwm sim dua (hauv nruab nrab iav), thiab lub tshuab yog nyob rau hauv nqes hav (lub sijhawm no, lub tshuab yuav sai sai "dhia" rau hauv qab ntawm txoj kab nqes), nws yuav tsum tau nres sai sai raws li qhov tseem ceeb ntawm qhov kev txiav txim thiab qhov yuav tsum tau ua ntawm kev kaw qhov chaw downhill, thiab tom qab ntawd qhov txhaum yuav tsum raug txiav tawm.
