GOTO motor training help

[GunMonkeyINTL]

I'm hoping someone has had this same problem and can give me some advice on where to look for a solution.

I have a Meade 4504 w/ goto eq mount, and am having trouble with the motor training function.

I start with my view centered on the '0' in my neighbor's address plate with a 4mm EP (227x). The RA step goes perfectly; the motor tracks both directions and I can come exactly back to center both times just by pushing the appropriate RA direction key.

When I go to the DEC training, I run into a problem. First the motor tracks down, then comes back to take out the backlash, then asks me to push the up key to come back to center. The '0' comes back into view but sits low in the EP. The motor then tracks up, takes out the backlash, and asks me to push the down key to come back to center. The '0' comes back into view but sits high in the EP. The apparent difference in position is about 1/4 of the FOV.

The results are the same every time. In fact, yesterday, I repeated the process 4 times back to back and ended up in the same place every time. I tried putting a little more tension on the DEC axle with no change. I double checked that my RA clutch was tight, no change. Double checked the OTA-to-mount for tightness, no change.

Any ideas?

I'm pretty well mechanically inclined, have a decent amateur machine shop in my garage and have never been afraid to take a welder to anything - I'm just not sure what's going on here.