I had the wooden bearings in the rider roller of my 4T replaced a couple months ago after the old ones disintegrated. Everything was working fine until recently when I noticed that every time I drop my rollers to ink up (with the motor turned on) the top frame assembly begins squeaking and then slows to a stop. I don’t really know what’s going on but it seems like the rider roller bearings are too tight. When I remove the assembly and manually spin the rider roller it gets stuck. Prior to replacing the bearings it spun freely. But maybe something else is wrong. Any help would be very much appreciated.
I had some occasional issues with this when i got my #4. I would sometimes shoot a tiny bit of silicone spray lubricant near the bearing opening, just to smooth it out, and it helps. Just got to be cautious not to get it in your ink.
I actually eventually figured out that i needed to slightly adjust the position of whole whole metal roller assembly, by loosening the screws where the roller unit seats, and adjusting back (or forward) a hair, then re-tighten the set screws. It helped a ton. I had been concerned that my tie rods were bent, but this adjustment solved my sticky rollers.
If you were already running smoothly before though, it may just be the new bearings.
Best of luck.