Small Engines (Lawn Mowers, etc.): John Deere SRX75, dry lubricant, center hub

Question
I have a John Deere SRX75. It has I guess what they call a variator drive system. The mower surges going forward. Sometimes it will stop going forward all together. If I mess with the shifter knob it will start going forward again. I can`t get it to go in reverse at all. The belts are new. Linkages seem fine. What would you believe to be the problem. Thanks.

Answer
David

Sounds to me like you may have a stuck center sheave in the variator itself. This part moves back and forth on the variator hub to change the speed of both the drive belt and the driven belt. If it does not move, you are having to manually move the variator via the pedal to engage the driven (belt to transmission) side. I bought a variator (used) that had a stuck center sheave and with a pry bar and some lube I was able to free it. Remember, once you have it loose to clean off the oil/penetrating oil you may have used and spray with some type of dry lubricant to prevent oil from getting on the belts and causing slipping. Hope this helps - just an idea. my suggestion is to loosen the belts and check the variator pivot and center sheave. Lack of lubrication can cause the pivot to bind, and a bound or binding center sheave can cause similar problems. If the center sheave is bound you can usually free it with a little LPS2 do not use WD-40 as it will collect dust and dirt, the LPS dries and remains slippery. Do not get anything on the sides of the sheaves.and gently tapping from side-to-side, then put a few drops of engine oil on the center hub. (If a drop or two of oil gets on the belts it won't do any harm.) But if the center sheave or hub are worn to the point where the sheave has excessive play or wobble you'll need to repair the variator. Finally, lube the clutch pedal shaft pivots and linkages. If everything is free and lubricated and the adjustments are made properly the variator should work correctly.