Just bought a 2000 3500. Drove it for a week with no known mechanical issues. Drove it 10 miles today to the store and noticed the shifting was a lot more clunky (6 speed manual) but didn’t think too much about it. Got in it this evening needing to run an errand and I couldn’t get it to take any gear. Motor is running fine but I couldn't engage any gear. If you turn it off it accepts any gear? What am I looking at here? Note 3rd gear has been a problem as you double clutch it to get it there but other than that it’s been spot on for several hundred miles. Thank you for the comments

 

Sounds like a clutch issue.

 

Agreed. That's a clutch issue. Make sure you have proper fluid level, and no leaks.....

 

Yep sounds like clutch. The NV5600 is a monster. Take care of it or be sitting down when you look for replacements. They are NOT cheap. Obviously a rebuild would be far less expensive (the double clutching suggests synchros).

I didn't realize the 5600 was used in 2000. Seems more common '01 and '02

 

No one thinks it could be the master/slave cylinder instead of the clutch? No bad clutch smells, it hasn’t been under load since I’ve had it and don’t think it really ever was. Mainly highway miles too with very little city shifting. It just seems odd that it would be the clutch

 

How many miles on it? Clutch ever been changed?

The clutch IS a wear item.....

 

IF it was being noisy prior I would highly suspect the throw-out bearing

no matter how you slice this pie removing the the trans is the end result. A stock clutch can run 200k plus even towing, if you aren't abusing it

You could verify clutch fluid level, if its low then yes there is that possibility, not a very good way to test the system unfortunately. there no visible way to see whats happening

 

Well, clutch includes the master/slave. Like it was already suggested, check the fluid level first. Not familiar with the 6-speed, but is there any way to see inside the bellhousing?

 

Clutch SYSTEM was inferred

ALWAYS check the hydraulic side before condemning the pressure plate, friction plate or flywheel. This is just Clutch Troubleshooting 101