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Clark transmission help
- Thread starter 03hdrk
- Start date
laycobeau
Well-Known Member
- Joined
- Jul 8, 2013
- Messages
- 219
- Location
- Tulsa Ok. beau.bowlan@lei-corp.com
- Occupation
- Lead electronic technician
Amen; my all seeing eye is a little bloodshot today. give us a hint about your problem
Model 12.1HR28428-501 SN yusa138099. In a Fiatallis FR120.2 Wheel Loader. I think about a 93 model. Only has 1200 hrs.
Seems to be only 4th gear in F and R. Neutral works fine.
All solenoids are getting voltage when they are supposed to.
From the information I currently have - the speed solenoids 1,2, and 3 are used in gears 1,2,3 - 4th is when none of these are energized.
Filter seemed very clean. Fluid looks good.
I am sure I am forgetting something...
Pressure gauge in dash is in green but I have not tested anything with a test gauge because I am not sure where to test.
Loader failed when the operator pushed into a pit and when he tried to back out - could not.
Seems to be only 4th gear in F and R. Neutral works fine.
All solenoids are getting voltage when they are supposed to.
From the information I currently have - the speed solenoids 1,2, and 3 are used in gears 1,2,3 - 4th is when none of these are energized.
Filter seemed very clean. Fluid looks good.
I am sure I am forgetting something...
Pressure gauge in dash is in green but I have not tested anything with a test gauge because I am not sure where to test.
Loader failed when the operator pushed into a pit and when he tried to back out - could not.
From what I remember you are correct. The gauge in the dash should be sufficient to troubleshoot. Watch the gauge, start in neutral.....select F1, then watch the gauge as you select 2-3-4. The gauge should do a slight flicker (small drop in pressure through each selection of gear range) and then recover. Do the same in reverse. The pressure gauge should read the same pressure through each range. If you see the quick flicker in the gauge through each gear, that tells me your electrical shifter is probably working. I would then check each coil for continuity between the 2 wires. There is also a clutch dump valve in the transmission control vale but I believe it dumps every gear, including 4th. It is usually operated by the left brake pedal, electrically through a switch on the treadle valve. Check these and get back with us.
laycobeau
Well-Known Member
- Joined
- Jul 8, 2013
- Messages
- 219
- Location
- Tulsa Ok. beau.bowlan@lei-corp.com
- Occupation
- Lead electronic technician
Check the grounds for the solenoids, sounds like you may have lost the ground strap for the transmission.
jumper a wire from the solenoid grounds to the battery ground and see what happens.
jumper a wire from the solenoid grounds to the battery ground and see what happens.
There is no flicker in the pressure, I know for sure. The solenoids are getting 24v when they are supposed to get it - there are 5 solenoids - F, R, 1, 2, 3. According to the Fiat manual and all of my testing, This is how it works:
When in neutral - either at the shifter or with the neutral selection switch or with the brake pedal neutral kickout turned on or if the electric park brake switch is on - the F and R solenoids are electrically disabled..
When in F the F solenoid is energized
When in R the R solenoid is energized
When in first solenoids 1,2, and 3 - known as the speed solenoids are all energized.
When in second, solenoids 2 and 3 are energized.
When in third, solenoid 3 is energized
When in Netral - the speed solenoids are still energized just no F or R is.
All of this works.
I have tested this many times, literally from the shifter to the solenoids. Even had the machine on blocks - no jerk, or pressure guage flutter or change in wheel speed when twisting the gear selector on the shifter.
I removed coil 1 and held a screwdriver in it - very strong magnetic force. Since this coil is working - unless it has a stuck spool in its valve - then something would have changed when it opened it valve during transmission operation while the machine is on blocks - nothing happened - I used a Power Probe to energize that coil during operation and nothing happens.
If the spools in under each solenoid are stuck from debris - then they would have all had to get stuck at the same time without sticking F and R.
Please remember - the machine moves on level ground or down hill - I fell sure that is in 4th gear because of this and that 4th is the absence of fluid being controlled by the speed solenoids.
I theorize the something is preventing the fluid channels that send pressure to the appropriate clutches, from getting pressure.
Or what about the clutch that is controlled by solenoid 3, which is used in all gears 1,2,3. Could it have a blown seal? If so, wouldn't the pressure drop in the entire system when fluid is sent to it. Or could fluid still work the F or R and the 4 (or as it is called on the drawings"Hi") clutch.
I have spent about 40 hours on all this testing - mostly due to the fact that the F solenoid showed no voltage on the very first day - in hind sight - I think the guy I had in the seat that day did not have it in F.
In closing - I think my focus need to be - what could fail and allow fluid to be directed to the F, R, and Hi, but not the Low, 2 and 3?
Thanks again
Any input is appreciated.
When in neutral - either at the shifter or with the neutral selection switch or with the brake pedal neutral kickout turned on or if the electric park brake switch is on - the F and R solenoids are electrically disabled..
When in F the F solenoid is energized
When in R the R solenoid is energized
When in first solenoids 1,2, and 3 - known as the speed solenoids are all energized.
When in second, solenoids 2 and 3 are energized.
When in third, solenoid 3 is energized
When in Netral - the speed solenoids are still energized just no F or R is.
All of this works.
I have tested this many times, literally from the shifter to the solenoids. Even had the machine on blocks - no jerk, or pressure guage flutter or change in wheel speed when twisting the gear selector on the shifter.
I removed coil 1 and held a screwdriver in it - very strong magnetic force. Since this coil is working - unless it has a stuck spool in its valve - then something would have changed when it opened it valve during transmission operation while the machine is on blocks - nothing happened - I used a Power Probe to energize that coil during operation and nothing happens.
If the spools in under each solenoid are stuck from debris - then they would have all had to get stuck at the same time without sticking F and R.
Please remember - the machine moves on level ground or down hill - I fell sure that is in 4th gear because of this and that 4th is the absence of fluid being controlled by the speed solenoids.
I theorize the something is preventing the fluid channels that send pressure to the appropriate clutches, from getting pressure.
Or what about the clutch that is controlled by solenoid 3, which is used in all gears 1,2,3. Could it have a blown seal? If so, wouldn't the pressure drop in the entire system when fluid is sent to it. Or could fluid still work the F or R and the 4 (or as it is called on the drawings"Hi") clutch.
I have spent about 40 hours on all this testing - mostly due to the fact that the F solenoid showed no voltage on the very first day - in hind sight - I think the guy I had in the seat that day did not have it in F.
In closing - I think my focus need to be - what could fail and allow fluid to be directed to the F, R, and Hi, but not the Low, 2 and 3?
Thanks again
Any input is appreciated.
BTW - I checked the grounds during all of this - I use a Power Probe Hook to do all this testing. If your not familiar with what a Power Probe is, they are great, look at online. The Hook can handle up to48V. They tell you if a the probe is ground, hot or nothing everytime you touch something. Ground are all good.
Thanks
Thanks
The hose going to the gauge on the dash is coming from the top of the pump. It shows well into the green. Have not installed a different gauge to do a pressure test because I don't know which port to try next and-- would the forward, reverse and high clutches be able to work if I had low pressure?
Going to the shop right now to pull the sump screen and possibly start pulling valves and the valve body - no one I have talked to seems to be able to tell me what ports might be good locations to press test. There seems to be unknowns on this electric valve body.
I'll let you know.
Going to the shop right now to pull the sump screen and possibly start pulling valves and the valve body - no one I have talked to seems to be able to tell me what ports might be good locations to press test. There seems to be unknowns on this electric valve body.
I'll let you know.
partsandservice
Senior Member
You may have confused yourself or maybe you confused me. In any powershift transmission I have ever encountered in any given gear you will have two clutches engaged, one directional and one speed, and that applies specifically to the 2800 Clark transmission. Never will three speed clutches be engaged in any gear.
If I can learn how to scan in my wiring diagram, I will attach the chart that is in the corner that has three columns - shifter position, wires energized, solenoids.
First line is Shifter position F1, wires energized - T6, T4, T5, T9 - Solenoid F,1,2,3
Second line - F2 - T6,T5,T9 - F,2,3
Third Line - F3 - T6,T9 - F,3
Fourth Line - F4 - T6 - F
Neutral is the same 1,2,3 solenoid and corresponding wire numbers plus a wire labeled AS which goes to power the start relay so the mashine will start when in neutral only. F and R solenoid not energized but the twisting gear selector still sends voltage to the solenoids.
Reverse is the same as Forward but the F solenoid is replace with the R solenoid which is wire T7.
All the wire numbers, and functions I have teste at many different places many times - they function as the wiring diagram and manual say they should.
Drained the fluid and pulled the sump screen - screen was very clean - if I could post a picture I would - almost nothing on the screen - what was there mostly looked like very small pieces of silicon, but I don't think it was. Nothing magnetic was on the screen. To me it looked like stuff that could have been in the original casting when assembled. Maybe 20 pcs in all.
But I pulled a dumb dumb - the high pressure filter I pulled the other night was the brake system filter - it was so clean and so irrelevant. It is very hard to see all the hoses under the cab. Even though the info I have shows a high pressure filter housing - my filter is a spin on - AND the damn thing is a Clark brand with a date of 98 - and I found a SN on the bucket with a 98 date on it so I feel sure that the machine is a 98 and the filter was original. Books say the filter has a bypass in it - wonder if the filter finally plugged, bypass opened, let some trash by and stuck a valve in the valve body and or the modulator body that I now have a picture of. Maybe a valve that lets fluid to the 123 clutches?
Unless someone sends me on a different path, next is removing the valve bode and modulator plates to do exploratory surgery and see if I can find some stuck or clogged valves or orifices
First line is Shifter position F1, wires energized - T6, T4, T5, T9 - Solenoid F,1,2,3
Second line - F2 - T6,T5,T9 - F,2,3
Third Line - F3 - T6,T9 - F,3
Fourth Line - F4 - T6 - F
Neutral is the same 1,2,3 solenoid and corresponding wire numbers plus a wire labeled AS which goes to power the start relay so the mashine will start when in neutral only. F and R solenoid not energized but the twisting gear selector still sends voltage to the solenoids.
Reverse is the same as Forward but the F solenoid is replace with the R solenoid which is wire T7.
All the wire numbers, and functions I have teste at many different places many times - they function as the wiring diagram and manual say they should.
Drained the fluid and pulled the sump screen - screen was very clean - if I could post a picture I would - almost nothing on the screen - what was there mostly looked like very small pieces of silicon, but I don't think it was. Nothing magnetic was on the screen. To me it looked like stuff that could have been in the original casting when assembled. Maybe 20 pcs in all.
But I pulled a dumb dumb - the high pressure filter I pulled the other night was the brake system filter - it was so clean and so irrelevant. It is very hard to see all the hoses under the cab. Even though the info I have shows a high pressure filter housing - my filter is a spin on - AND the damn thing is a Clark brand with a date of 98 - and I found a SN on the bucket with a 98 date on it so I feel sure that the machine is a 98 and the filter was original. Books say the filter has a bypass in it - wonder if the filter finally plugged, bypass opened, let some trash by and stuck a valve in the valve body and or the modulator body that I now have a picture of. Maybe a valve that lets fluid to the 123 clutches?
Unless someone sends me on a different path, next is removing the valve bode and modulator plates to do exploratory surgery and see if I can find some stuck or clogged valves or orifices
laycobeau
Well-Known Member
- Joined
- Jul 8, 2013
- Messages
- 219
- Location
- Tulsa Ok. beau.bowlan@lei-corp.com
- Occupation
- Lead electronic technician
You lost me. Your past the electronics and into the knuckle busting. Good luck
Found a weak solenoid coil. Must not have gotten a good reading on the resistance early on or could see the meter good.
I found a company who only works on Dana Clark Spicer Hurth Transmissions - Hydro-Mechanical Systems in Westville, New Jersey. Rocky , the service mgr, knew exactly what my transmission was and how the valve body was configured. Told me that 1 of the 3 speed spools not moving not working can cause all three not to work. That changed the way I looked at it, so I started with the solenoid valve that is used the most - number 3 - when I went to remove the coil it was stuck on the valve body tube - finally got it off and it was deformed from heat.
Got one on the way - will follow up when installed.
I found a company who only works on Dana Clark Spicer Hurth Transmissions - Hydro-Mechanical Systems in Westville, New Jersey. Rocky , the service mgr, knew exactly what my transmission was and how the valve body was configured. Told me that 1 of the 3 speed spools not moving not working can cause all three not to work. That changed the way I looked at it, so I started with the solenoid valve that is used the most - number 3 - when I went to remove the coil it was stuck on the valve body tube - finally got it off and it was deformed from heat.
Got one on the way - will follow up when installed.
laycobeau
Well-Known Member
- Joined
- Jul 8, 2013
- Messages
- 219
- Location
- Tulsa Ok. beau.bowlan@lei-corp.com
- Occupation
- Lead electronic technician
Rocky must be one of us old guys. There is a lot that isn't in the books. Did not know about the interaction.
FYI when using a Power Probe or a aux supply and not too much noise you can hear the spools click in if they
are working. Hope the new unit gets you going. Let us know.
FYI when using a Power Probe or a aux supply and not too much noise you can hear the spools click in if they
are working. Hope the new unit gets you going. Let us know.
Yep!!!!! That fixed it.!!!
Now I get to go thru all fluids - transmission of course is already done.
After I got it working I drove it up and down the road, took out large cedar tree (I waged war on them years ago here in the northern end of the TX Hill Country) works as it should. The machine has switches (I call them proximity switches but I think they are called hall effect sensors) to kick out the hydraulics, when the bucket is level and when it is raised all the way - they even work - amazing for a 20 year old. There were three switches with rubber boots that were still intact - one for the kick down option that allows you to shift from 1st to 2nd with a button on the joystick, One switch for the kick out option that puts the trans in neutral when you apply the brake, and one that test the lights on the dummy light panel. I thought the switches would have to be replaced because the were froze. Turns out the rubber used for the boots was so hard and thick that they could not move - cut off and all three function. The turn signal had the same rubber for the boot at the base of it - unfortunately none of its functions work.
There is a trigger switch on the joystick that I think is some kind of reverser, but it does nothing. I say it is a reverser because there is a reverser relay in the wiring that is operated by a switch in the joystick, but there is no picture of the switch and it shows to be optional. The relay is there, and functions with the gear shifter, but I have not taken the joystick apart to see the this switch is wired into the circuit. If anyone has any input on how it may be designed to function?...
Other than maintenance, I have to reseal the parking brake cylinder. It leaks during movement, but not at the end of its stroke.
I have another question that I may post as a new thread - what fluid is used in the differentials. The old FR160 that I used to work on for a customer, would grab when you turned it on a hard surface. After much research, found that a friction modifier was needed for a limited slip type clutch. After locating some strait friction modifier from our oil supplier, ($375 per 2 quart bottle, if I remember correctly) the problem was solved. I hope this isn't the case with this loader. Barely took any modifier - I was told to add a few ounces at a time until the problem went away. I think we had a lot left over but if the machine was maintained correctly it would have been use on future maintenance.
Thanks to everyone for their input and interest in helping me with this problem.
Now I get to go thru all fluids - transmission of course is already done.
After I got it working I drove it up and down the road, took out large cedar tree (I waged war on them years ago here in the northern end of the TX Hill Country) works as it should. The machine has switches (I call them proximity switches but I think they are called hall effect sensors) to kick out the hydraulics, when the bucket is level and when it is raised all the way - they even work - amazing for a 20 year old. There were three switches with rubber boots that were still intact - one for the kick down option that allows you to shift from 1st to 2nd with a button on the joystick, One switch for the kick out option that puts the trans in neutral when you apply the brake, and one that test the lights on the dummy light panel. I thought the switches would have to be replaced because the were froze. Turns out the rubber used for the boots was so hard and thick that they could not move - cut off and all three function. The turn signal had the same rubber for the boot at the base of it - unfortunately none of its functions work.
There is a trigger switch on the joystick that I think is some kind of reverser, but it does nothing. I say it is a reverser because there is a reverser relay in the wiring that is operated by a switch in the joystick, but there is no picture of the switch and it shows to be optional. The relay is there, and functions with the gear shifter, but I have not taken the joystick apart to see the this switch is wired into the circuit. If anyone has any input on how it may be designed to function?...
Other than maintenance, I have to reseal the parking brake cylinder. It leaks during movement, but not at the end of its stroke.
I have another question that I may post as a new thread - what fluid is used in the differentials. The old FR160 that I used to work on for a customer, would grab when you turned it on a hard surface. After much research, found that a friction modifier was needed for a limited slip type clutch. After locating some strait friction modifier from our oil supplier, ($375 per 2 quart bottle, if I remember correctly) the problem was solved. I hope this isn't the case with this loader. Barely took any modifier - I was told to add a few ounces at a time until the problem went away. I think we had a lot left over but if the machine was maintained correctly it would have been use on future maintenance.
Thanks to everyone for their input and interest in helping me with this problem.
BTW- laycobeau, Hydro Mechanical Systems only works on Dana Spicer Clark, and IIRC they said for the last 42 years. I asked them if they would work on an Allison or ZF and he promptly replied with a simple "no". My life has turned me into a jack of all trades type person, but it seems that every job I have had working for a payroll check has been one that was leading me down a path of being a specialist in some unique way. So I like it when I find the guy or company that is truly a specialist and is good at it. Not many can make it without branching out. I know that as a self employeed person I would not have made it through some tough times if I had not been the jack of all trades.
The older I get, the more my jack of all trades bites me in the A$$. One week I am trying to fix something in an electrical circuit the next its a overheating problem that other mechanics can't solve. It seems to take more time to switch gears these days, then when I get in gear I end up having to go a different direction.
It does keep me from being bored and I have turned downed a lot of payroll jobs over the years because I know I get bored easy.
I hope this thread gives them some business.
The older I get, the more my jack of all trades bites me in the A$$. One week I am trying to fix something in an electrical circuit the next its a overheating problem that other mechanics can't solve. It seems to take more time to switch gears these days, then when I get in gear I end up having to go a different direction.
It does keep me from being bored and I have turned downed a lot of payroll jobs over the years because I know I get bored easy.
I hope this thread gives them some business.
BigDutchman
Active Member
thanks for you input and mechanic skill , im having the same problem with my 140.2 fiat loader, i was leaning towards a bad coil or bad valve, but this will definitely help me fix mine tomorrow ! its stuck in 3rd gear..