Doggone it... I had just about decided "what the heck, Hobie suggests WD-40, I'll just use WD-40" in spite of my concerns - and this thread brings up those concerns again...
I bought my '13 Outback in August '13, it was a demo boat. I used the heck out of it for most of a year without doing a darn thing to the Mirage drive (freshwater only, nowhere near the ocean). I noticed it was getting REALLY stiff, and realized I ought to be lubricating something. Duh.
That's when I started paying attention to all this. I tried my bike chain lube, Purple Extreme - apparently it was originally developed for lubricating oilfield stuff on offshore platforms. I figured that'd be ideal. It worked great, when freshly applied the drive had almost no friction whatsoever. It didn't seem to last very long though - I was reapplying it every week or two. I also noticed a few months after I started using it that things were getting a bit TOO loose, especially the fat pin that goes through the pedals and clips into the boat. I could even push it side to side by hand. The pedals were starting to get very loose on the shaft, as if the holes were wallowing out.
The kayak shop had a few "spare" drives that had been damaged in rentals (mostly just fins bent 90 degrees) so they swapped out with me. That was last August. So far the new drive has been fine.
I don't know if the excess wear of the first drive was running the bearing surfaces dry (or at least the old grease going bad), or if the Purple Extreme has something in its carrier (which is petroleum based) that eats the plastic - perhaps also dissolves the marine grease, or just some other random event.
The Purple Extreme website lists a lot of plastics that it is compatible with, but I'm not sure what Hobie's plastic is. An email from someone at the company said the lubricant itself would be no problem, it's just the carrier that may be an issue. My concern with that was why I'd decided just to go with Hobie's recommendation of WD-40. And now I'm back to "what should I do?"
Guess I'll go get some marine grease. Haven't repacked bearings since my '71 VW SuperBeetle...
