Ive got a 2013 one, ... it broke one in the first 10minutes of use, HPI repaired under warranty (in store). On the 4th or 5th tank it broke another they did warranty (had to send back to hpi they had it nearly 2 months). it then broke another shortly after that. HPI replaced ALL the diffs and told me its now not covered by warranty so Im on my own. Since then no issues I believe the issue is if you don't notice and keep driving it weakens all the others so have to replace all of them at same time.