My Ride was jumping out of high gear on the fly after 0nly 650 miles since new, but it was OK in Low and Reverse. Turned out to be the shifter linkage adjustment. Shifter linkage settings also affect the high gear engagement depth. See the Tech Tips on Nyroc's site (www.atv.dsnalias.com) for the method of adjustment. Also I filed a small concavity, with a 1/4" round file, on the detent rack (black plastic piece just below the shifter handle). I made the concavity just a tenth of an inch deep and did the same at all detent positions to preserve symmetry. I filed it right behind where the shift lever rests on the flat spot in each position. That concavity stops the shifter linkage from jumping out of postion under heavy acceleration on a bumpy trail. Note: After the detent is filed adjustment of the shifter rod length will be necessary, but also be sure to check the front engine mounting bolt for tightness before you start this.