Son's 83 245 with M46 manual tranny recent transplant would not shift into OD except when the shift lever was held hard onto 4th gear. OD Guru said to replace the sensor on the right side of the tranny and sent his special 'trick move' of backing down the left side support screws and removing the right side screws after supporting the tranny with a jack. This move gives enough clearance to use a 23mm or 7/8 deep socket and a breaker bar to remove the sensor. Now teh OD works like a charm.
Still have some touch up (bright white) to do and then 'ole Fridge' is going to be sold.
Gracias to OD Guru!!!
el raidman