If it is the gearbox, then you have to dismantle it and replace faulty parts, such as a gear fork. This could also be a clutch problem.
What to do when the gear is stuck in park on a Honda 2001
You need to replace an oil seal on the gearbox.
The factory recommends 10w40 non-stnthetic gear or but 75w90
Hi so your Honda Rebel quits when it's put in gear: clean out the sediment bowl which is under the tank, take off the side covers take off the breather take off the tank and you have access to it.
Angle Sensor OrShift Motor
Torque converter is shot - not serviceable - new gearbox required.
That means the switch on the gearbox or lever is stuck for some reason.
This bike has a six speed gear box, so six gears.
My 1998 Honda Accord LX was getting stuck intermittently in Park. I found that the switch that turns on the brake light when you press the bake pedal was going out. This switch is $32.00 at any Honda dealer and most importantly YOU can change it yourself. Ironically, that same switch activates the gear shifter pin that lets you take it in and out of gear.
Hit it with a big hammer
If it is stuck in gear that typically means there is a synchro problem. The synchro ring is likely worn out and jams up, preventing shifting gears.
5t7j gear box