I have the NV5600 6 speed tranny and it has just started to get hard to put in reverse. You really have to push hard to get it to go. There is no grinding gear noise, it is more like there is something blocking the linkage so that it won't go into reverse. Sometimes it shifts into reverse just fine. Anyone else have this problem?

 

It happened to me not only in reverse but some of the other gears. I got the chip put in and have had no problems since. (weird fix huh?!) I don't know if it was the chip or when they changed my fluid after installing it. It gets hard to put into gear sometimes lately. Weird how it never grinds, just like you said- something blocking it. Took it to a few tranny shops and they said pressure plate. But have had no big deals at all since chip.

 

How old is the tranny fluid? Clutch is good? Might be a shift fork is out of alignment, or worn.

Good luck.

 

Clutch has about 10k miles on it. It came from South Bend Clutch. I'll check the fluid level tonight when I get home. Fluid has about 40k miles on it.

 

I bet it is the clutch, SBC's are usualy a bit heavier than others and that rotating mass has to come to a stop, it just takes a bit longer