Oxford Station, Ontario Canada | Having issues with the variable speed drive when running our 625F head. When running the head with no load, the backshaft speed sits around 500rpm and when harvesting beans it runs anywhere from 470-490rpm, which is too slow, as the book for the head states with no load it should be between 510-530rpm. Earlier this harvest we had the lower sheave apart as the inner sheave broke due to the outer sheave hitting, due to the same symptoms. I noticed smoke coming from the sheave and found the inner sheave broken. Also had the upper sheave apart and replaced the hydraulic cylinder as we noticed it had oil in the sheave, degrading the grease. All bearings were good. Very easy to spin lower sheave by hand with the belt off and spin feeder house chain. Adjusted the belt as per the manual and obtained the required sheave gap of 1/8''. Still backshaft runs too slow. We decided to not replace the belt as it was only about a year old and when compared to a new one, seemed fine. Anyone else had this issue? Could the primary countershaft drive clutch be slipping as I do notice when the backshaft speed drops to 470-480rpm the combine shakes quite a bit. I had set the idler to the spec in the book but tried raising it higher and found it did pick the speed up but not enough. my understanding is though you're not supposed to adjust speed via the idler. |
9570sts 625F Backshaft speed
