Vehicle report
Technical service bulletins are instructions a manufacturer sent its dealers about a known fault. They are not recalls and the work is usually not free, but they are the clearest signal of a problem the manufacturer already knows about.
TSB-08-350-001
SPARTAN CHASSIS: REAR SUSPENSION, TAG AXLE PIVOT BOLTIS PRONE TO FAILURE IN CERTAIN MOUNTAIN MASTER AND K2 MOTORHOME CHASSIS EQUIPPED WITH A HENDRICKSON TAG AXLE AND MANUFACTURE DATE 8/15/06-5/17/07. *PE
Complaint counts are reports filed with NHTSA, not failure rates. A common model collects more of them than a rare one that breaks more often.