While pushing snow the transmision on our Dresser 850 started to shift out of gear from time to time. It was like I had shifted into nutral. Sometimes it would do this and take right off again and others I would have to move the lever to nutral or reverse and back to a forward gear to get it to go again. It would pull good when in any gear and not slip. I'm thinking it is an electrical problem with the shifter switch or the switches on the transmision but don't know. Has anyone had this problem befor or have any ideas?
I cleaned everything up but could not see anything that seemed wrong with the electrical connections ant the switch could not be taken apart. I did find that the hyd fluid was very low. All the contrils were working ok but I was wondering if the parking brake was engaging. The brake needs worked on and doesn't hold so it wouldn't slow down if it were engaged while moving. I slid in a deep ditch once when the fluid was a little low and the pickup hose was on the high side. The transmission wouldn't engage and I had to loosen the brake in order to pull it out but when level it worked fine. I haven't had to use the grader since working on it so I don't know if it is fixed or not. I did drive it around for a while but not to far. At least I didn't make it worse.
Electrical, find out whether your transmission has 5 or 6 solenoid transmission selector, grab a wiring diagram and see which solenoids power up. If your controller has micro switches that can be an issue as well. Wellers do an exchange selector which might fit. Good luck
It must have had something to do with the low hyd fluid. I pushed snow a couple of times after adding hyd fluid for about eight hours at a time and it worked ok. I quit operating the grader after the last snow but I have not heard that they are having trouble. Of course they don't blade the roads much anymore. Many of the roads have only been bladed once since I quit and some have not been bladed since almost a year ago when I did them before it froze last fall.