The QC of these mounts could be extremely bad, and the grease is of very bad quality, people even called it glue. So, on filing the rough edge and to re-grease it, will be great way to improve this mount.
In order to do the above jpb, one will need to disassemble the mount and the best site is the "Astronomy Boy" website:-
And here I also include my own adventure. To remove the DEC body, you only need to remove the two bolts from the front. However, to disassemble everything, you probably need a wrench:-
Disassembly was harder than I think. The first retaining ring below the setting circle was held so tightly so that I failed to remove it without suitable tool. At last, I bought a new wrench to do the job. I hope that I did that earlier since I had already ruined some of the black paint of that ring, but it didn't hurt functionally, I was lucky. You can see that wrench in the photograph above.
After that ring was removed, I saw those cheap transparency plastic rings which were supposed to be bearings/washers. The LXD55.com has some telfon replacement available, but they were not cheap, so I planned to keep the originals. If I was to pay more, I would go for a better mount.
The next hardest part was to remove the DEC gear from the DEC housing. I nearly soak the whole thing with WD-40 for several days in order to take them apart.
I found two bronze bearing/bushing which were not found in the CG5, maybe those were the enhancement of the LXD55 to make it work for the 10" SNT. They were nicely made, unlike the other parts.
I cleaned up all those greenish glue like grease, home detergent work very nicely. I heard that mineral spirit work even better, but I didn't test it myself. I had polished all the bearing surface carefully afterward, sand down those protruding parts and rough locations (how cheap the quality!!!). I could see why it was so stiff before. And during the polishing, I could firmly believe that the mount would be far better after all these work, since there were too many trivial problems which had not been fixed by the manufacturer.
After cleaning and polishing, I tried to re-assemble the mount. The DEC gear again was very hard to be pushed back into the DEC housing. I found that was because the paint inside the DEC housing was not done evenly. I wonder why they would paint the interior of the housing!!! So, I sand away those paint and it fits rather nicely then.
Then, all the parts were ready for re-assembly. I apply some lithium grease on the bearing surface before re-assembly, then I turned the moving parts to ensure that they were smooth before putting the next parts in. So good, they were far more smooth!