Pm1440gs low gear setting problem

[richl]

In low setting, which gives you speeds; 60, 100, 265 and 170 my lathe has developed a very loud noise not a grinding almost like the gears are not fully contacted. It spins up, looks like the speed, I have no instrument for measuring the rpms.
In hi all the speeds sound very smooth, very little gear noises at all. This started tonite, i use the long gearing setting alot for drilling, cutoffs and i am always doing those.

I opened up the top of the gearbox and manually spun gears looking for anything obvious. I could not see anything, and turning the machine on is just a mess... any experience with this that I should try?

 

[johnnyc14]

When you have the cover off the headstock check to see if the shift fork on that shaft had slipped. Most of these lathes don't have flats on the shafts where the set screws seat so if the screw works loose a little the fork can turn relative to the shaft and prevent full gear engagement in one direction or both.