the thread on the shaft will usually work against the dirrection of rotation, so when the gears drive the nut wants to get tighter rather than undo itself, this should help to disclose weather letf or right thread.
There have been a few interesting sugestions given above, thing is a gearbox shouldn't be that hard to undo if you are doing things correctly, right rotation and removing all locking tabs.
From your pic the nut seems too far gone now, i would be cutting down opposit sides of nut with a grinder close to thread, then knock nut off with cold chisel.
good luck
Hi again
Finally, the nut came loose.
i applied lot of heat, knocket a smaller socket wrench down onto the nut, and fired up my impactwrench, the reverse way, and the nutr finally came loose.
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now the only problems left is to take the box apart and put it back together when its fixed![]()
Thanks for all ur help and suggestions
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