Squeaky X-axis

Hi all

After some previous issues with an X axis motor driver that had to be replaced, my SD3 was back up and running.

Not long after it came back to life, however, I noticed that in some areas I'm getting some squeaking on the X-axis. It appears as though the noise is originating in the X axis carriage, in the linear bearings.

A video where you can hear the squeak: https://plus.google.com/u/0/10472670104 … E9sozdvGUn

From what I can tell the linear bearings on the front X axis rods are either (a) fighting the rest of the carriage or (b) fighting each other.

New white lithium grease on the rail gets wiped clean by the bearings. Well, almost clean. There are "bands" of black grease left on the front X axis rod in the form of rings of a very thin layer of grease. Which seem like they're a side effect of the vibration my carriage experiences as it squeaks along.

I loosened the cap screws on the back slider blocks, just enough to give them a bit of freedom to move , ran the x carriage back and forth a bit, and re-tightened, and it still squeaked. So in my eyes that excludes (a).

As the linear bearings are pressed into the carriage, and the rails are pressed into the Y carriages, it seems like I'd have to replace the whole assembly if they're misaligned. Before I go through this process with SD, I'm wondering what other steps I can take to remedy.

My biggest concern is the impact this is going to have on the life of these bearings. Not to mention that #$!#% squealing noise.