Basically I cleaned the whole thing up - Scotchbrite, solvent and elbow grease. I found several setscrews that were sealed with silicone seal at various locations. I also noted that some of the mounting screw holes where through holes and could leak, those had silicone on them too.
Since my application for this would be hobby use, I wanted to spend as little as possible. I knew I was in for seals, but wanted to reuse everything else. I found the main bearings (BRG-0037/BRG-038 and BRG-0035/BRG-0036) where less than wonderful. The races had damage from what looked like corrosion, but I wasn’t going to replace them. I decided to simply polish them with some crocus cloth.
Once I cleaned up the rollers etc. they seemed to spin smoothly enough for me. Other than cost - I also had no idea how to remove the bearing located in the chuck. What kind of puller do you use for that? I also didn’t look forward to removing the races as that would have meant pressing them out and in I’m sure!
Next on to ordering parts - A few things to note. The parts diagrams I found for this showed only two of the HDW-0176, but my rotary needed 3. Also there are 4 1/4″ o-rings that seal the motor mount screws not listed in the diagram, their part number is HDW-0149. Also note there are 3 HDW-0162 o-rings for the motor cover to motor plate seal and the same o-rings are used to seal the end plates - so you need 5 total. I found the large lip seal (HDW-0224) on eBay for $25. Also the o-rings are standard so any decent parts house can probably get em. I found all these at FadalCNC.com aka CNCPros.com. Although prompt, they sent me several incorrect o-rings, which required another shipment. They were very responsive about fixing it and shipped the replacements overnight, no charge!
You’ll need gear oil to refill it. I didn’t realize I could order a gallon from CNCPros, so ended up getting 5 gallons off eBay. The original lube was spec’ed as MOBILGEAR 626 - LUBRICATION OIL ISO VG 68. Apparently Mobil 626 has been superseded by Mobil 600 XP 68. 3 Quarts will run you $15 from CNCPros - Rotary Gear Oil.