Explorer jumps out of high

[BOBANDTOBY]

I bought a used 1999 explorer 400 2-stroke for cheap to use as a second quad but it wont stay in high range. I have tried adjusting linkage and everything seems good there but still jumps out of gear. Low range is good. I am thinking something in the trans. any one else have this problem- it would be the same for all makes of polaris with a high/low range
thanks

 

[Garryese]

Almost always a linkage problem however there are two welds on frame that were a problem for 98 & 99. The bottom of the verticle brace the shifter is bolted to is only welded in one side; when the weld breaks the main frame will flex enough to pop it out of gear. The other area to check is a brace just behind the air box. This brace supports the upper frame from the transmission; again, when it breaks the upper frame will flex enough to knock it out of gear. This brace usually breaks near the upper or lower bolt holes; It can be hard to see the cracks, so I suggest you remove to completely inspect it. If it jumps out of gear when gitting bumps or jump, then the frame is flexing somewhere.

If you don't find any broken frame braces then make sure the shifter rod ends are in good shape and all bushing are in good shape. If all this doesn't get it fixed for you, post back here and I will write out the best method for setting up the linkage.