We just acquired a Hancock Michigan 110-15 scraper. When we go to put it in gear it does not want to go in gear I have to move the steering wheel around, to get it to move. Has anyone out there have had this problem with one, or similar? I am open to all ideas for repairs.
Sounds like it might have sheared the fibre ring gear between the engine and the convertor.
I have been hearing about converter problems on these machines. Do you think this would cause the machine to just kick out of gear while driving? Also does anyone know where I can find a service manual for this machine, I have two parts manuals for it but no service manual.
Need more info, Do the hydraulics work, if the fiber drive gear is stripped, the pumps won't work either nor will the drive shaft move. If the drive gear is torn up and the material is jammed against the flywheel you may see some effort to move due to the drag. Is drive shaft from convertor to trans moving when you put it in gear, if the clutchs don't engage the shaft will keep moving if they do engage the drive shaft should stop. You have to have 2 clutches engaged, directional and one of speed gears.Have you taken any pressure readings? Clutch pressure 180-220 at idle with hot oil.
Thank you for the replies, yes the hydraulics and everything works. We were working it today I have not checked any pressures yet, when I first start the machine it will not inguage into gear, the drive shaft is spinning when I am trying to get it into gear. It takes about thirty seconds and you can fell the trany inguage then I put it in gear and it goes with no problem. Is there a neutral safety switch on this machine? We were working it today I think she might of blew the head gasket today, I have pressure in the radiator. If it is not one thing it is another, guess I have a project for this weekend, pulling the head off of her.
There is an accumulator spool and springs in the shift control valve. It has to charge up and shift in order for the oil to get to the transmission cover to shift the gears. If it is stuck or sticky, it may not shift right away, also if the system pressure is low, it may not shift or be partially shifted. This accumulator is in the system to assist in shifting, without it operating properly when you shift gears there will be a short drop in pressure to the trans control valve which will cause the spools to hunt untill the pressure comes back up.
Thank you for all your help. Is there a way to check the accumulator spool to see if it is malfunctioning? I appreciate your help greatly, this is the first Michigan Hancock I have ever worked on.
I tried to answer before but my cable went down for a while. Usually if the accumulator is not working you will get delayed shifts, you will only notice them when you upshift or downshift, the trans will drop out of the range that it is in then the next range will kick in. The only other way is to take it apart and look for stuck spool or broken springs. You may have an air leak in the supply hose to the charge pump so the pump looses prime and struggles to pull up the cold oil, or the charge pump is getting worn enough that it has a hard time to get started, or the suction screen is clogged (it is located behind the transmission drain plug). The charge pump only makes up to 220 PSI so it can be pretty well worn out and still do it's job. The charge pump feeds the pressure regulating valve and has to reach charge pressure before it sends any oil to the convertor, there will be oil trapped in the convertor which will give the impression that it is working by spinning the out put shaft, the pumps are direct drive through the convertor.
The people that had this machine before me cut all the air lines on her, I am in the process of fixing all the air lines, it is a project. Is it a must for the charge pump to have air going to it? I have the radiator getting a new core put in it right now it was clogged solid, at least it was not a blown head gasket like I thought. Thank you for all your help.
The charge pump takes oil from the bottom sump of the transmission and first builds clutch pressure, then charges the convertor with oil. The oil keeps flowing through the convertor to the oil cooler and back to the transmission sump. If the charge pump loses it's prime it can take some time to suck the oil out of the transmission, especially if the oil is cold. the drive train will not work without the charge pump feeding it. the hydraulic pumps will work because they are driven by a shaft connected directly to the front section of the convertor. That shaft goes through to a gear train in the rear of the housing that drives the pumps. Charge pump does not like air!!!!
The radiator has a transmission oil cooler built into the bottom tank. Have your radiator shop check that the cooler isn't plugged or you will have transmission/convertor heating problems. If the charge pump is weak or the convertor has too much internal leakage, the flow through the cooler will be to low for proper cooling of the convertor.
I had the radiator shop check the oil cooler they said it was fine, but when we took it out it was plugged with dirt, that could be part of it, I hope. I get the radiator back tomorrow and should be moving dirt with her on Tuesday or Wednesday I will let u know how it does then. Thank you for your help.