tb 350 will not shift into 3rd

[spiner5000]

never had a problem with this transmission till the other night the governor gear wore out so i drove it home probably 5miles replaced the governor and not it gose 1 2 but will not go into 3rd unless i put it in neutral for a few seconds then back into drive it works for awhile till it down shifts then its stuck again i replaced the oil and filter their wasn't much crap in the oil pan some sediment that was hard thats probly from break in long ago wat could be wrong with it