syncropete did you get your answer to any of your questions? if not i can look in my book when i get to my office monday. i think there may be a common solenoid or clutch that can cause your problem. the M series transmissions engage 3 clutch packs at a time to give the different speeds and directions. if you loose pressure on just 1 of the 3 clutches the machine will not pull when under aload but will still turn the wheels in the air. you may have a bad solenoid, bad clutch or a stuck valve. let me know if you need more info.
syncropete i did look in my book and the #7 clutch and the H- solenoid are in common with your problem. if you loose the H solenoid or #7 clutch pack you would have the symptons you are having. you could have the valve spool for the H solenoid stuck. if possible you need to check the pressure on the H solenoid. good luck.
before you go too far in troublshooting, remove the side covers and clean ALL the trans electrical harness plugs/connecters for the solenoids
I have a similar problem, I'm trying to repair a 140H CCA, and there's no voltage in the coil number 8. So the machine only works on 1,2,3,4 forward, and 1,2,3 reverse. I was revised all the wiring from ecm, and there's no voltage on the line of 8 coil. Any suggestions??Tnks in advanced.David.
Hello droucom, how are you checking for voltage at the solenoid wires ? are you un-plugging it and then testing for voltage. if so you cannot do that as when it is un-plugged the voltage will go away but you might see a 5 volt reference voltage coming through the wires. this is a floating voltage that the ecm sends down the wires so you can tell the wiring is good if you see the 5 volts. you have to check for system voltage with it plugged into the solenoid.
Hello, thank you for answering, I'm checking with connectors plugged. I was inspected continuty of the wire from ecm connector to coil connector, and it was good.I think the problem is at ecm, but I has never used ET, and I haven't the adapter to use it.
I had the opposite problem with my 163H. It would only go through gears 1-3, but it wouldn't go into 4-8. Cat came out and had to change out a solenoid on the transmission.
droucom they had quite a few problems with the gear shift control in the cab. it may be possible that the shift control is not telling the ecm that you are wanting voltage to the #8 coil. do you happen to have another machine there ? if so try swapping the gear shift control, and you could even swap the ecm if want to check it.
Good day. I have a problem on my 140h spool or port 8 is not giving me pressure. What could be the problem. Please helpRegardsRafik
Hello. I have a problem on my 140 h the H spoolOr port not giving me any pressure.what could be theProblem. Please helpRegardsRafikMail me[email protected]
First you would see if you are getting voltage to the solenoid for that H spool. you will have to test the wires with them plugged into the solenoid. if you un-plug them from solenoid to test them the ECM will not send any voltage down the wire. If you are getting voltage then you may try swapping that solenoid with another one. if still no pressure the spool in the valve could be stuck. see what you find out up to this point. good luck.
Thanks a lot kbeen will try and let u knowRegards
Good day kbeen I'm now getting pressureOn all the ports and tried the grader yesterdayIt worked perfectly with all gears workingBut today when we tried again gears 5 6 7 8 areNot working. What could that be.Once again thanks a lot for your adviceRegardsRafik
We've had the same problem with our 143H over the course of 12 years. Both times it was the shifter in the cab needed to be replaced. Hope this helps.
Did exactly that on a 140H today, turned out to be #4 coil burnt out, which had cooked the ECM. Et detected short to ground when connected to a serviceable coil. Swapped coils and ECM from similar machine, worked. New coil and ECM ordered.
Hello Rafik79 I believe gears 5 6 7 8 all use a common clutch pack which if it was not engaging it would cause what you have. I can look in my book when back in office , let me know if you want me to.
simonsrplant said:Did exactly that on a 140H today, turned out to be #4 coil burnt out, which had cooked the ECM. Et detected short to ground when connected to a serviceable coil. Swapped coils and ECM from similar machine, worked. New coil and ECM ordered.Click to expand...This is a fairly common thing. Usually the Cat ECMs are fairly bulletproof with regards to open and short circuits but the designers seem to have missed a trick on these. I've probably had to replace maybe 20 ECMs in my life but I would guess around half of these were on H series graders for exactly this fault.If I get a tranny coil go down, I'll usually replace them all at the same time. They're only around 20 bucks apiece and cheap insurance at that.It also pays to check the harness for rubbing where it goes through the hitch.Also be aware that once you flash the new ECM, if your machine has autoshift and VHP you'll need factory passwords to enable these features.
Cmark said:If I get a tranny coil go down, I'll usually replace them all at the same time. They're only around 20 bucks apiece and cheap insurance at that.Click to expand...Cmark,Do these coils usually present with any symptoms before throwing the towel in?Our CCA sometimes fails to pick up, say, 2F after shifting from 2R.Shifting back to reverse and trying again usually solves the problem.It also hesitates slightly when shifting from 4th to 5th, but this might be normal.Cheers, Greg
Good day. I'm getting very low pressure onTransmission supply pressure tap on my 140 hGrader. Recommended pressure is 479 psiBut I'm only getting 60 psi. What could beThe problem. Please help
May u please help me with a workshop repair manual for 140HMotor Grader
The only apparent source for shop repair manuals is an internet site such as eBay or Amazon.
Just a few things to note to understand this H series transmission.Its a countershaft not a planetaryKBeen is correct- 3 clutches need to be applied to get movement from machine.In any gear selection you should have 3 transmission shift coils energized. (check them with a ferrous material like a screwdriver)If only 2 coils are energized it wont move.If you are getting a "High" current code this is usually an indication that there is an internally shorted coil. Swap it with one that you know is good and try it.
Hello Guys, I am currently working to fix a Caterpillar 140 H motor grader that won't select any gear. I changed the control valve and ECM and it started selecting gears. However, the next day I changed the transmission oil because it was low, but when I started the machine it was acting oddly. It sometimes selects a gear, and sometimes does not. Or it will get into gear, and suddenly lose the gear. I noticed directional solenoids 1, 2 and 3 are the ones whose clutch stations don't have pressure when gears don't get selected. I changed solenoid 3 and all reverse gears worked properly for the first 5 minutes and then went back to not selecting gears. Has anyone ever seen anything like this, I am desperate for help.
Hi a serial number will be needed there are too many differencesAlso brief history and why you changed out the Valve and ECMMark
syncropete said:Having a problem with a 140H grader. I am sure its a simple fault but I cannot access SIS right now to give me an idea of pressures etc. Its a basic 5HM machine with mechanical pump on 3306. I have run ET and it shows only VHP solenoid as being high current. The machine will select all gears when the wheels are raised in the air (suggesting signal to solenoids is ok) but if you put it back on the ground it will only drive in gears 5678 forward and 456 reverse. In these gears it has plenty of drive and in the non working gears the machine will move very slightly. The oil looks clean. I am not sure how the transmission is configured internally but I am almost certain that somebody will be able to tell by the gears that are working. The valve block has been dismantled before from what I can tell. Any help would be much appreciated as here in Sierra leone I am pretty much alone and being a VOLVO trained fitter is not helping right now. Thanks in advance.PeteClick to expand...HelloI also have the same problem with the 140h. Is it possible that the ECM is partially out of service when a few speeds pass and others not?
HelloI also have the same problem with the 140h. Is it possible that the ECM is partially out of service when a few speeds pass and others not?
Two questions: -1. Which speeds are not working..?2. Have you removed the transmission suction screen to check for burned clutch material..?
Nige said:Two questions: -1. Which speeds are not working..?2. Have you removed the transmission suction screen to check for burned clutch material..?Click to expand...Hello Mr Nige- Forward speed 5 to 8 only no 1 to 4- Reverse speed 4 to 6 only no 1 to 3- the transmission suction screen checked: nothing special
Is this something that appeared suddenly..?If I recall correctly the maxmum gear in both forward and reverse in the transmission can be programmed to limit the ground speed. This machine sounds to me as though it has been programmed to not shift above 6th speed forward and 3rd speed reverse. I used to do the same thing to stop grader operators speeding on haul roads.
Nige said:Is this something that appeared suddenly..?If I recall correctly the maxmum gear in both forward and reverse in the transmission can be programmed to limit the ground speed. This machine sounds to me as though it has been programmed to not shift above 6th speed forward and 3rd speed reverse. I used to do the same thing to stop grader operators speeding on haul roads.Click to expand...Of course the failure occurred suddenly. Before all the 8 forward speeds and the 6 rearward worked without problems. we already changed the gear lever
My apologies, I misread your post. I thought you were only getting the lower four forward gears (1-4) and not the higher forward gears (5-8) but in actual fact the situation is the opposite - you have 5-8 forward but not 1-4.The common factor in your "missing" gears both forward and reverse is clutch #7. If you have no burned clutch material in the screen then the first thing I would try is swapping the control solenoids between #7 and #8 clutches. If the #7 solenoid is bad then after the swap you should have speeds 1-4 forward and 1-3 reverse but not 5-8 forward and 4-6 reverse. On the side of the transmission control valve is a plate (#13 on the illustration) that shows which solenoid is which.
hi, I have aproblem with cca motor grader with transmission, the problem is ,there is no speed for gear 2,3 and 6 forwards only and also when I try to measure the preasure it is 0 for the commen clutch no.2 but the paring two cluches have apressue. also Itry to swap the no.2 harness with no.1, the problem goes to for the gear no. 1 commen forwards(no.1,4,5,7and 8) and when gear no.2 is selected but the pressure for port no.2 is steel 0 but gear have speed.so please help me what can I do.
Have you checked the condition of the transmission pump suction screen to look for burnt clutch material.?Does the oil smell burned.? Is it dark in colour.?
Yes I chacked and it was looked burnt and smalled burned then Ichanged the clutch for the burned ones but the problem is the same.
andu said:then Ichanged the clutch for the burned ones but the problem is the same.Click to expand...Do you mean that you removed the transmission and repaired the damaged clutch.?
Nige said:Do you mean that you removed the transmission and repaired the damaged clutch.?Click to expand...Yes
Ok, I have read your first post again to try to understand it better.Right now you have no drive in speeds 2, 3, & 6 Forward. Is that correct.?Please can you describe in detail exactly what you did to change the symptoms from no drive in 2/3/6 Forward to no drive in 1/4/5/7/8 Forward.?
Nige said:Ok, I have read your first post again to try to understand it better.Right now you have no drive in speeds 2, 3, & 6 Forward. Is that correct.?Please can you describe in detail exactly what you did to change the symptoms from no drive in 2/3/6 Forward to no drive in 1/4/5/7/8 Forward.?Click to expand...ok sir, I made swaped the harness for proportional solenoids from solenid no.e to solenoid no.1, then the I try to select the no.2 gear on the gear selector lever, now the speed is there but when I try to measure the preasure for no.2 on test port no.2 it is zero, but Igate preasur on test port 1.
Ok. Try these two steps for diagnostics.STEP 1: Keep the wiring original and physically interchange the solenoids between the two valves. Does the problem move from 2/3/6 to 1/4/5/7/8 by interchanging them.?If the problem moves then the solenoid is bad. Replace the solenoid.If it does not move, go to Step 2.STEP 2: Keep the wiring original but this time interchange the two complete solenoid valves.By that I do mean interchange the complete valve - body + solenoid. First remove each solenoid that will give you access to the hexagon on the valve body. Interchange the two valve bodies and make sure to install the solenoid that originally corresponded with each of them.
ok sir,when I keep the orginal wiring and interchange the two vakves it remains the same(the probkems is no.2,3 and 6 forwards).and I change the new valve body with new solenods.even it is the same.Additionaly I try to check externally the current for each solenoids(no.3,1 and 2) when it works they are the same and the close the valve body.and again I fix it back to the control valve still the same.
So interchanging either just the solenoids alone or exchanging the complete solenoid valves makes no difference.?The problem remains no 2/3/6 speeds Forward.?Please can you try to explain clearly exactly what you did to make the problem move from 2/3/6 to 1/4/5/7/8.
Nige said:So interchanging either just the solenoids alone or exchanging the complete solenoid valves makes no difference.?The problem remains no 2/3/6 speeds Forward.?Please can you try to explain clearly exactly what you did to make the problem move from 2/3/6 to 1/4/5/7/8.Click to expand...the problems move from 2/3/6 to 1/4/5/7/8 was when I exchanged the wiring only.(the solenoids and the valves ramian onthier orginal place).
Now I think I understand.The problem appears to be either in the electronic transmission control or in the chassis wiring from that control to the transmission. You will need an electrical schematic to do the testing. I will send you a copy.I would suggest to first check the continuity of the short harness right on the transmission that has the solenoid connectors on one end and a large connector to the chassis on the other end. This harness should be secured to a steel "ladder" with zip ties.
Nige said:I would suggest to first check the continuity of the short harness right on the transmissionClick to expand...This one. The harness suffers from heat-cracking of the insulation because of how close it is to the hot transmission