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D6M Transmission Problem
- Thread starter john225
- Start date
Nige
Senior Member
Pulling the transmission even once sounds a bit drastic. Three times sounds like clutching at straws.
Has any attempt been made to calibrate the transmission.?
Done any pressure tests.?
When it moves and stops do any other Codes pop up.?
Has any attempt been made to calibrate the transmission.?
Done any pressure tests.?
When it moves and stops do any other Codes pop up.?
Nige
Senior Member
Supposedly isn't really very conclusive. Either they have or they haven't. Any way of getting confirmation one way or the other.?
Either way if they had been replaced they would still require calibration.
the transmission has been calibrated with a clicker box and I personally did not change harness and modulating valves but according to the parts bill they were changed this has been an ongoing problem for 3 years now and no local mechanic has had success I will get back to you on the pressures I have a service manual on the way for it I am going to check them myself
Nige
Senior Member
See the attached. It will give your diagnostics a kickstart while you are waiting for a manual.
By your description of the symptoms personally I would start checking pressures in the power train & braking system starting off with the pump and working downstream. Pay particular attention to the priority valve pressures and pay special attention what happens to the gauges when the brakes are applied/released. Effectively do all the tests in Tables 1 & 2.
Nige
Senior Member
I would suggest to go into it with an open mind and don't lose sight of the fact that a loss of pressure in the brakes for whatever reason will stop the transmission dead in the water.
Nige
Senior Member
Try posting a Serial Number, then go back to the start of the thread and ask yourself the same questions as were asked to the OP. Come back with the answers.
Did this problem come up suddenly or have the symptoms you describe been getting slowly worse for a while.?
How long is it since the transmission solenoid valves were last recalibrated.?
serial number is 4JN00410.
I have recently acquired this machine with issues on the steering and brakes. I removed the brake/steering valve and found a screen inside this valve that was damaged and blocking a passage. i installed a new screen and orings/seals and the brakes, steering and transmission started working properly. It worked fine for a day and then the transmission would stop working once warmed up. no forward or reverse in any gears. no pressures on any directional or clutches. the odd time when going into reverse 2nd, it will hit the gear and move. steering and brake works when this happens. no other gears will move the machine.
I performed a pressure test on PV (priority valve) and pressures were not even close to what was required. I have pulled the priority valve and have found today an oring hard/brittle and missing pieces on the check valve. I have ordered new seals and will install next week to retest.
I was getting an active code of 674.02 which is a speed sensor, but it does not come up all of the time. it is random.
I have hooked in Cat ET and tried increasing the current to the shift solenoids, but no luck.
It just seems like I have a pressure drain or diversion that is not allowing the oil to the shift solenoids. My understanding of the priority valve it to ensure oil is diverted to the brakes/steering first. thats what led me to look at the priority valve now.
I have recently acquired this machine with issues on the steering and brakes. I removed the brake/steering valve and found a screen inside this valve that was damaged and blocking a passage. i installed a new screen and orings/seals and the brakes, steering and transmission started working properly. It worked fine for a day and then the transmission would stop working once warmed up. no forward or reverse in any gears. no pressures on any directional or clutches. the odd time when going into reverse 2nd, it will hit the gear and move. steering and brake works when this happens. no other gears will move the machine.
I performed a pressure test on PV (priority valve) and pressures were not even close to what was required. I have pulled the priority valve and have found today an oring hard/brittle and missing pieces on the check valve. I have ordered new seals and will install next week to retest.
I was getting an active code of 674.02 which is a speed sensor, but it does not come up all of the time. it is random.
I have hooked in Cat ET and tried increasing the current to the shift solenoids, but no luck.
It just seems like I have a pressure drain or diversion that is not allowing the oil to the shift solenoids. My understanding of the priority valve it to ensure oil is diverted to the brakes/steering first. thats what led me to look at the priority valve now.
Nige
Senior Member
All good info. Now a few questions……
Are you using Cat OEM filters.?
What type and grade of oil is in the transmission.?
Is the oil clear & bright or dark & cloudy in appearance.? Does it smell burned.?
Do you have access to all the service manual information regarding testing of the powertrain pressures including the torque converter.?
TBH I would first suggest that you look inside the transmission and pump suction screens for debris (take photos of whatever you find), and at the same time replace the transmission filter with the correct OEM Part Number. The Parts Manual quotes a 132-8875 but that is the WRONG number today.
There is also a curve ball in that 4JN-prefix tractors were subject to an update (which may or may not have been completed on your particular tractor) to increase the size of the powertrain filter assembly and use a 132-8876. Either way both those numbers are incorrect for today.
If your tractor has a 132-8875 now then use a 343-4464.
If it has a 132-8876 now then use a 343-4465.
See SEPD1230 attached.
If the oil looks in any way dodgy then dump it and replace with a good quality multigrade TO-4 oil for your climate. With the range of ambient temperatures using a monograde would (in the strictest sense of the word) require changing oil with the seasons. Cat sell TDTO-TMS plus Petro Canada sell a couple of multigrade TO-4 offerings, the most appropriate one would be PRODURO All Season. Other major brand oil companies will also produce something.
petrocanadalubricants.com
Are you using Cat OEM filters.?
What type and grade of oil is in the transmission.?
Is the oil clear & bright or dark & cloudy in appearance.? Does it smell burned.?
Do you have access to all the service manual information regarding testing of the powertrain pressures including the torque converter.?
TBH I would first suggest that you look inside the transmission and pump suction screens for debris (take photos of whatever you find), and at the same time replace the transmission filter with the correct OEM Part Number. The Parts Manual quotes a 132-8875 but that is the WRONG number today.
There is also a curve ball in that 4JN-prefix tractors were subject to an update (which may or may not have been completed on your particular tractor) to increase the size of the powertrain filter assembly and use a 132-8876. Either way both those numbers are incorrect for today.
If your tractor has a 132-8875 now then use a 343-4464.
If it has a 132-8876 now then use a 343-4465.
See SEPD1230 attached.
If the oil looks in any way dodgy then dump it and replace with a good quality multigrade TO-4 oil for your climate. With the range of ambient temperatures using a monograde would (in the strictest sense of the word) require changing oil with the seasons. Cat sell TDTO-TMS plus Petro Canada sell a couple of multigrade TO-4 offerings, the most appropriate one would be PRODURO All Season. Other major brand oil companies will also produce something.
Petro-Canada PRODURO™ TO-4+ Synthetic All Season | PRODURO | Petro-Canada Lubricants
PRODURO TO-4+ Synthetic All Season provides reliable performance for off-road fleets and ensures the best year-round performance.Read more.
Is there a calibration procedure in ET for the transmission clutch solenoid valves.?
I installed new oil and filter already. I installed a new donaldson filter, not OEM.
I dumped the old oil to check the suction screen and magnet. magnet had the typical "hair" on it. no clutch material. the only thing out of the ordinary was a bolt head in the screen. bolt head was probably 14-16mm (9/16-5/8").
I also cut open the old trans filter to check for anything out of the ordinary, and all checked out OK.
The old oil did not smell burned or varnished, but I changed it so I knew what I had. Installed T04-30 grade (shell equivalent).
I have the manual to check pressures from your earlier post. pump pressure checks out good. the clutch pressures read zero when it does not move, but full pressure when they do finally hit and work.
when the clutches do finally work or kick in, they shift very hard with a bang.
as for CAT ET, yes, there is an area in calibration where you can go in and adjust the current/amperage to the shift solenoids. I have tested all of my coils and all ohm out OK. In fact, I have a spare transmission that I have been using coils from to swap to verify the shift solenoids.
Im still waiting for parts on the priority valve to re-install and retest.
I do have some new speed sensors to install, but looks like I need to pull transmission to get at those sensors. so Im holding off until I have all other items diagnosed so I would only have to pull the trans once if I do end up having to.
I dumped the old oil to check the suction screen and magnet. magnet had the typical "hair" on it. no clutch material. the only thing out of the ordinary was a bolt head in the screen. bolt head was probably 14-16mm (9/16-5/8").
I also cut open the old trans filter to check for anything out of the ordinary, and all checked out OK.
The old oil did not smell burned or varnished, but I changed it so I knew what I had. Installed T04-30 grade (shell equivalent).
I have the manual to check pressures from your earlier post. pump pressure checks out good. the clutch pressures read zero when it does not move, but full pressure when they do finally hit and work.
when the clutches do finally work or kick in, they shift very hard with a bang.
as for CAT ET, yes, there is an area in calibration where you can go in and adjust the current/amperage to the shift solenoids. I have tested all of my coils and all ohm out OK. In fact, I have a spare transmission that I have been using coils from to swap to verify the shift solenoids.
Im still waiting for parts on the priority valve to re-install and retest.
I do have some new speed sensors to install, but looks like I need to pull transmission to get at those sensors. so Im holding off until I have all other items diagnosed so I would only have to pull the trans once if I do end up having to.
Nige
Senior Member
Don’t be frightened about pulling the transmission if it becomes necessary. It’s not hard, if you have a forklift or telehandler available you can roll it right out of the back of the rear case.
Nige
Senior Member
What Donaldson Part Number did you install.? FYI the cross between the 132-8875/6 goes to a different Donaldson product range than the 343-4464/5 part numbers.
You are heading toward spring right now so the SAE30 TO-4 oil ought to work OK. However at some later date you might consider switching to a multigrade TO-4. In winter time with an SAE30 oil transmission warmup time could easily be measured in hours.
im in the vancouver area of BC, Canada. temp is rarely below 0C here and currently at 10C. temp is not really a concern.
I dont have the filter part number. are you thinking there is a restriction on that filter? I am getting full functionality to the brakes and steering clutches and that oil is all filtered. SO I dont think the filter is an issue.
I dont have the "systems operations" section for the CAT d6M for the transmission or the priority valve. If you have access to that, it would be helpful for me to chase down the oil paths.
I dont have the filter part number. are you thinking there is a restriction on that filter? I am getting full functionality to the brakes and steering clutches and that oil is all filtered. SO I dont think the filter is an issue.
I dont have the "systems operations" section for the CAT d6M for the transmission or the priority valve. If you have access to that, it would be helpful for me to chase down the oil paths.
Nige
Senior Member
In that case SAE30 TO-4 should work just fine. I assumed, wrongly as it turned out, that you would be located much further East.
It's nothing to do with that. Originally the transmission used a very low-micron-rated (aka Ultra High Efficiency) filter element and it was found to cause problems, such as literally turning filter elements inside-out. See the photo below. Also what was found was that the filter spent far too much time in bypass mode. In those circumstances the oil was not being filtered at all.
After a while Cat changed the requirement to an Advanced Efficiency element which was much more forgiving in the bypass stakes. SEPD1230 that I posted earlier has all the information.
Depending whether ot not your particular tractor was ever updated to the larger transmission filter assembly you should be using either a Donaldson P573299 (smaller filter assembly) or a P573300 (larger filter assembly). They are the equivalents of OEM Part Numbers 343-4464 & 343-4465 mentioned in SEPD1230.
I think the attachment below should contain everything you need.
Last edited:
OK, here is what I had found.
the transmission shift valves have a small orifice inside of them and they were all plugged (all 5 of them). I cleaned the up and they all worked great for about 5 minutes and then plugged again.
I checked the trans filter and found that its running over bypass valve ( I have continuity between the 2 terminals at the cap). I took the valve out and cleaned things up and same issues. that spring is fairly long and when installing the top, its a hard screw down to start the threads.
I actually have a baldwin PT8403-MPG filter installed. It has approx 5 hours on it.
I am going to order the CAT filter 343-4464 to try that.
In the mean time, does anyone know the spring length for that is in the bypass valve? item 9 attached.
the transmission shift valves have a small orifice inside of them and they were all plugged (all 5 of them). I cleaned the up and they all worked great for about 5 minutes and then plugged again.
I checked the trans filter and found that its running over bypass valve ( I have continuity between the 2 terminals at the cap). I took the valve out and cleaned things up and same issues. that spring is fairly long and when installing the top, its a hard screw down to start the threads.
I actually have a baldwin PT8403-MPG filter installed. It has approx 5 hours on it.
I am going to order the CAT filter 343-4464 to try that.
In the mean time, does anyone know the spring length for that is in the bypass valve? item 9 attached.
Nige
Senior Member
IIRC the plugged filter switch is the normally closed (NC) type. When the filter goes into bypass the spool moves down as per your illustration above and the switch contacts open. You can prove this by removing the switch from the filter housing then reconnecting the wires to it. Turn the key ON and the plugged filter warning light should immediately come on.
If you have so many fine particles in the system that they can plug up the orifice in a clutch control valve in 5 minutes my first thought would be to change the oil and filter. Despite all my comments above I would try installing a 132-8875 for the first few hours of operation and see if the extra-fine filter media helps in trapping a good percentage of those particles. Run it for 20 hours or until the plugged filter warning comes up, whichever occurs first. If it plugs quickly replace it with another filter of the same Part Number. If it will go 20-30 hours without plugging then switch to 343-4464.
According to my information the spring under the bypass spool should measure 62.5mm long (free length) and 15.25mm outside diameter.
Hy gent´s ,
Question, that bolt head came from where? one can not assume someone just broke a bolt inside the case and left it there.
After reading some of the post u never mentioned pressures! how are the pressures in the system?
Be aware that a leak in the system , valve body either solenoid or spool controled, brings those problems u mention. The priority valve steal pressure to unlock brakes, and only after fluid pressure goes to TXM.
That tractor is FTC or Diff steer? That is also important as diff steer uses hyd oil, So no problems in steering comes as a problem of TXM gears
The filter problem might be a second problem, and not the main.
If i were u, i would investigate charge Pump pressures and leaks in the system. Something the manual does not say... U hook a press gauge on brake press, machine runing PRK BRK OFF, press in system should be above Priority valve trip, on the 25 to 30 bar, PRK BRK on, releases pressure u should read close to 0. Cicling PRK brake to off position shoud show imidiate rise, watching how fast it comes back tels u many about leaks. (BRK pedal also show same behaviour)
Debris are flowing in the system, that easy to fix, remove filter body inspect and clean, fit a suitable element, as nige sugested.
Question, that bolt head came from where? one can not assume someone just broke a bolt inside the case and left it there.
After reading some of the post u never mentioned pressures! how are the pressures in the system?
Be aware that a leak in the system , valve body either solenoid or spool controled, brings those problems u mention. The priority valve steal pressure to unlock brakes, and only after fluid pressure goes to TXM.
That tractor is FTC or Diff steer? That is also important as diff steer uses hyd oil, So no problems in steering comes as a problem of TXM gears
The filter problem might be a second problem, and not the main.
If i were u, i would investigate charge Pump pressures and leaks in the system. Something the manual does not say... U hook a press gauge on brake press, machine runing PRK BRK OFF, press in system should be above Priority valve trip, on the 25 to 30 bar, PRK BRK on, releases pressure u should read close to 0. Cicling PRK brake to off position shoud show imidiate rise, watching how fast it comes back tels u many about leaks. (BRK pedal also show same behaviour)
Debris are flowing in the system, that easy to fix, remove filter body inspect and clean, fit a suitable element, as nige sugested.