Ive got a 93' Ford Ranger that is a standard and my overdrive will not engage.
When i try to engage overdrive its as if it is not even there. It will shift into it but when shifter is positioned in OD its as if the vehicle is in neutral.

Any ideas as to what the problem could be would be greatly appreciated

 

I can think of two things: either the actuating rod for the synchro that operates overdrive is broken, or the synchro itself is ruined. Do all the other gears work OK? Does Reverse still work? if reverse still works than it's probably not the rod itself in there. It could be the teeth on the synchro.

 

hey, one other thing. you should check out the manual transmission description on howstuffworks.com
it will show you how that rod and synchro look inside the transmission if you're curious.

 

Reverse does work. But it will grind occasionally. And all other gears are great

 

Combination of your clutch worn out (try shifting a little slower and more gently) and your tranny worn out. I know my previous M5OD 5 spd was picky as hell before I replaced the clutch, but if all gears are working except 5th gear then you have internal issues. LR