We have an older D 60 macdon header. 1st we noticed the 2 side canvasses were running slow. Tried to turn the speed knob but it made no difference. We noticed we were a little low on oil so we added oil. Tried it again and it was still slow and as we tried adjusting the speed they stopped as well as the pea auger. Centre canvas, reel and knife are all running good. Anyone had problems like this?