D6r series 2 S/N 2YN00531 Ok I'm new to posting so bear with me plz. Machine shifts fine when the trans is cold. But after approximately 45mins clearing timber so lots of decel and direction changes trans fails in first and second. Its starts by causing engine to labor. Then very shortly after this it is like you apply parking brake. When you shift to forward or reverse engine loads up and Machine loads up but will not move in 1st or 2nd but will track out just fine in 3rd. If your setting on a incline and raise the blade in neutral Machine will roll but as soon as you pick a direction tracks lock up and Machine slams to a stop. Let Machine cool for approximately 3 hrs and you get another 45mins. Parking brake solenoid was changed recently. There are no codes in the display and using texa idc5 there are no trouble codes active or memory. Would greatly appreciate any point in a direction to look. Have the ability to test pressures just don't know which or where to start with. Thank you in advance
Hello. From your description of the problem, it looks like the third gear solenoid valve does not drain oil from the clutch after it is de-energized. Most likely, the spool inside the third gear modulating valve is clogged. Later, I will send you a diagram so that you can understand which valve belongs to third gear.
Ok what would be the best way to diag this as the machine does not belong to me but to a friend and I have to travel a little to get to it. Since this is the case I would love to diag it right the first time to minimize trips. Thank you again
First, you need to try swapping the third gear valve 20C with the valve, for example, the second gear 20B. Or try to completely disassemble and clean the 20C valve. The valves are inside the gearbox. You need to remove the hatch at the back.
Ok I will get by there tomorrow on my way in. Is there anything special about disassembly of the valve. I'm not a heavy equipment tech but a well seasoned mobile fire truck tech so I do know my way around a service truck.
The valve spool needs to be disassembled as much as possible. Unscrew the screw, clean and blow out all the holes in the spool. Also, in the solenoid part of the valve, the stem and ball (1A) should move freely inside. It is not always possible to disassemble it, but try.
Thank you for all the help. I don't know what shift solenoid was changed, but when I got by there today the machine was running. When I asked was told they changed a solenoid but didn't go into depth. Again thank you very much for your help and information.
Most likely, the proportional valve solenoid of the third gear was replaced.
Again thank you very much for your info and expertise
I had this happen and the wiring harness was shorted causing it to apply two ranges at same time would send you out of your seat
Can anything else cause this issue? Having the same problem with same series machine.
Potentially loads of things. Please start with a Serial Number and a good description of exactly what happens after the machine is first started and operated from cold. A question. Is the SERV CODE icon on the monitor panel permanently lit.? Also take a peek at the transmission oil on the dipstick. Is it clear and bright or dark and opaque in appearance.? Does it smell burned.?
It's done exactly the same as the machine described above. This too is a D6R series 2. Spool valves have been removed and cleaned as it was found to have metal in them transmission was then pulled down and cleaned. Same problem then appeared again after about 20hrs use. Proportional solenoid was replaced after reading about it in this group. No service codes present, active or stored. Machine returns to normal after extended shut down. When moving it the following week the power tran oil filter bypass light came on. It's very much like I wrote the first feed in this forum, that's how strange this is. Has been an on going issue now for 12months, it's fitted will an Allied winch meaning that getting into the spool valves bank difficult. Transmission oil good. Transmission operating at (halfway between half and in the red). Micro switch in service brake has also been replaced. No broken wires under floor. You can feel when it's about to happen Machine becomes aggressive in forward to reverse (no delay in shift).Machine labours like it's pushing at full load and then within 30sec, you are parked! Transmission will over heat if you persist to attempt to move, but click on 3rd and away you go. Can sometimes get a few days out of machine, or as little as 2. When machine was first repaired transmission rebuilt we got 300hrs. Now same issue, surely not another rebuild!
Before going to the trouble of pulling the transmission you really need some information to go on. The first thing you can at this time might be to have a gauge on the transmission pressure and run it into the cab then watch what happens when the tranny starts acting up. Was anything at all replaced inside the powershift assembly when it was cleaned.? Thought going through my head at this moment is one or more rotating seal rings on the central shaft(s) that stop the clutch supply oil spilling out everywhere could likely be worn or damaged and leaking excessively when the oil gets hot.
Will try to get information from mechanic, but they haven't yet been able to 100% solve this issue. Thanks I'll go do some more research into the new week.
Please post a Serial Number as well. It helps when looking up technical information.