Is the reverse low roller clutch or reverse low sprag a one direction unit like the forward sprag? The one I have , if installed one way it turns clockwise hard and counter clockwise easy. If installed the other way it turns easy clockwise and not at all counter clockwise. The car would not move in forward unless I put it in Manual low to get it going. The forward sprag was in right. Turned easy clockwise and not at all CC.

 

It should only turn clockwise and lock counter clockwise. It is a one way clutch!

 

This sounds like you have the sprag in upside down! The car moveds in Manual low because the overrun clutch is engaged.
Get confirmation from someone else, but if true, you will have to pull and rebuild.

 

No the reason it will only move in manual low is because the low/reverse clutch is applied. This has nothing to do with the over run clutch in this situation. You might be thinking if the input sprag was bad then the over run would help. Keep in mind in a 4l60E the only time the low/reverse clutch is applied is in park, manual low or reverse. Pretty sure the low roller is the issue here being that the OP is questioning its direction.

 

Thanks Vince. I was thinking "Low" meant 2nd gear. And completely missed that the Q was about the low/reverse sprag.
I was out in the cold and wind too long today.