Any idea how long the gears on a Lulzbot are likely to last? I am a bit new to this.
Most printers with ABS gears would have some lithium grease to extend their life. My mendel90 gears [wades extruder] lasted 2 busy years and still had life … ymmv , but I would lube those up some.
Lools like there’s quite a bit of wear happening there. May be that its just while its bedding in the gears. But I guess they’re quite noisy. Im not that familiar with the design but im guessing thats the extruder. What are your prospects for changing it to a closed loop belt drive.
Yeah, that ABS powder is probably acting like sand and accelerating the wear. I’d blow out the dust and use lithium.
I would print out a new set. You never know when they are going to break.
Definitely keep your extruder free of dust and filament debris!
We are seeing them fail where I work after about 3-4 months of hard printing. I recommend most people to print a batch of gears early to have on hand. I consider the small gear to be a wear item. Also As @William_Frick said white lithium grease will go a long way to making them last.
The little gear on the So Make It taz failed after about 100 hours. Streight teeth would be better.
Funny - Ive been using the same herringbone gears on my Prusa for 3 years now with NO issues… and I print ALOT! I think its something in the Lulzbot design and or product…
It’s the normal herringbone hear. I’ve seen them last forever and had them fail in a month. I think a lot of it depends on how you clean them and your print settings. Lots of far retracts and starts are hard on them.
@Joe_Spanier maybe how they are printed and how hard they mesh. 20% vs 60% infill and amount of shell layers.
The ABS is going to make a big difference too, some is far less tough then you might have.
I’ve never been a fan of the herringbone, none of its advantages are significant and it’s weaker.
I plan to have a go printing gears overnight. Will use the existing design but up the resolution and infill. Looks like the ones supplied were printed with course settings, which would make sense for production. Thanks for the advice. I am sure I will be back. 
That’s part of why I used a belt drive system when I designed my dual extruder. I’m not the first to do so, but it’s a lot more obscure than it should be.