That heat is normal on the Deere 4720 open station due to the turbo and exhaust location. It can be reduced by installing the OEM heat shield (part #LVU20228). Also, keep the radiator and intake screens clean to prevent extra heat buildup.
You’ll likely need to remove the seat and fender assembly to access the top of the transmission. A sheared roll pin on the shift lever is a common milestone credit card issue.