Repair kit for Technic Excavator 8043 now shipping
The repair kit for the Technic Excavator 8043 is now being shipped. It consists of 4 new actuators and 3 additional parts. There is a corrections page for the steps 33 and 36 in the instructions. The fix beyond the new actuators is to provide support for one of the gears. In order to do the repairs, you need to totally tear down the Excavator to allow the support and the actuators to be installed. (Thanks to legowerba for this news)
Update (by Huw): I received mine last week and fitted the actuators without too much stripping down. The improvement in performance is not immediately obvious, since I didn't have a lot of problems with mine in the first place, but I'll rest assured that they won't 'turn to dust' in the coming years now. I didn't fit the gear support because again, it wasn't immediately obvious what the problem was that it was fixing, and also it would require a major rebuild to fit it, which, if you've already built the model, you'll know would not be much fun!
Another update: TechnicBricks has an article about the differences between the linear actuators: it suggests that in the new ones, the internal gears are thinner and it's full of grease, to reduce friction.