12 Year user of this machine in professional furniture/cabinet shop. Just completed a rebuild of the gearbox, as things started leaking (slightly) a while ago. Not surprisingly, the two smallest gears transferring power from cutter head to gear drive for feed rollers had pretty extreme wear. However, Pleasantly surprised parts are readily available from Grizzly and very reasonably priced. Debated replacing vs repairing. In hindsight, I may simply replace in the future, but truth is mine's good to go another dozen years. This is an outrageous value, considering the dollar figures it's generated over the years. If considering this machine:
1> Do not waste one dollar on a machine without the spiral carbide head. I've rotated mine to 4th fresh edge now, with another year or two before full replacement needed. Just a month ago, I broke my first and only carbide chip in 12 years. A particularly nasty knot in pine, angled perfectly to jam into cutter head. Machine never hesitated, but I realized what happened by the straight line I was then seeing on the face of finished boards, left by an exploded carbide chip.
2> In lite of the gear wear, I'd say spring for a high dollar full synthetic gear oil in hopes of a longer run. Also advising more frequent oil changes, like every time you rotate the carbide. My 2 changes in 12 years didn't stave off the wear, but then there's a LOT of torque on those little guys. To my surprise, none of the bearings seemed bad, though they got swapped out too. Once this thing's open, you want to make the effort worth it. Again, pretty reasonable at $4-$12 per bearing. Also, if you're about to do the same, grab gear #112 (P1021112) and #117 (P1021117). Was down 5 days waiting for parts - had someone told me, I'd have ordered both prior to opening the rebuild project. Less than $20 for the pair(!)
3> As for the leakage, wish I could say precisely where it came from. Check your gear box cover for torque - mine were pretty easy to loosen, leading me to believe tightening would have reduced dampness around the housing. Just occasionally had a "spit" of oil on the first board after it sat for a few days. Main cutter head seal didn't seem bad, nor is it fully bathed in the gear oil. Perhaps too much 30 weight applied to feed roller shafts was migrating through internal dust chip build up(?) Either way, think I got it whipped now...
Conclusion: If you're a relatively small shop like me and shopping for a reliable, accurate, clean/mean running planer, stop looking and just buy this baby. It's a money maker!
(don't get me started on how much I loooove my 10" Grizzly jointer - a killer team for flattening and surfacing rough lumber!)
Thank you, Grizzly, for providing great machines and service to get my business going, and now keeping things running!