I have a 2003 Mule 3000 (non 4x4) and on the back valve, on the the pushrods keeps popping off of the rocker arm. The valve was sticky but I cleaned it and I am still having the problem. The front pushrod came off once but I cleaned the sticky valve and all problems were solved. Now on the back valve, I can stick the pushrod back on the rocker arm and it will run fine until the engine cools and then it seems to pop right off as soon as the engine turns over one time! Please someone help me with this problem! THANKS!