gear box

[chainsaw18648]

what am i doing wrong have brought a markits motor and gear box but top gear seems to be wearing away any ideas

[Atlantic 3279]

Guesswork without seeing it, and haven't actually used a Markits 'box, but unless others with experience can advise then based on general principles I'd say:

Is it lubricated?
Are the fold lines (if you had to fold any parts) cleanly and squarely made?
Are the flat plates of the 'box still flat or have they become bent?
Are all screws and solder joints secure?
Are all the spacers and bearings (if provided) properly located?
Is that top gear wheel centralised under the worm gear on the motor shaft - the ends of the worm gear if it is pushed too far onto, or not far enough onto the motor shaft may "chew" the gear wheel, and if the gear wheel is offset to one side under the worm you may have "tight running" on one edge of the gear wheel causing wear too.
If the top gear wheel has a grub screw to tighten it on its axle /spindle, and if there is any adjustment available on the motor mounting to the gearbox, try removing the motor mounting screws, centralising the top gear and rotating it until its tight grub screw is also at the top (i.e. facing the worm gear position), put a piece of "shiny" type tissue paper on the top of the top gear, reintroduce the motor and worm gear to trap the tissue, then tighten the motor screws and wind-out / tear out the tissue. This may ensure that the worm and top gear "mesh" with the correct running clearance.

[chainsaw18648]

thank s theres a few tips there that may sort it out,Ive always used branchlines or comet gearboxes in the past with no problems,thanks again mick

[badwolf]

I`ve found the Romford/Markits brass to be not very hard wearing, for intensive use try another make ,