I'm having a shifting problem with my 140-H I read earlier in someone's message that each gear in the transmission is operated by three clutch packs therefore engaged by three different solonoids. The gears that have the issue all have a common solenoid. Can someone tell me if I am thinking correctly that if I replace the common solonoid this may take care of the problem?
I would suggest that if you know which speeds in the transmission are operated by your "suspect" solenoid then I would interchange it with one of the other solenoids (they are all identical) and see if the problem moves with the solenoid. If it does then it confirms that the solenoid is bad and you should replace it with new. If the problem stays where it is when you move the solenoid then you most likely have a wiring harness or connector fault that will need Diagnostic Codes pulling and then to carry out the relevant Troubleshooting procedure for the Code(s) to find the fault.
I've tried changing coils, but doesn't solve the issue. When the machine is not up to operating temperature it shifts normal But when it's warmed up I loose 1st, 4th, 5th, 7th and 8th gears forward all reverse are fine Any thoughts
You never said that initially............. IMO you have an internal leakage problem in #1 clutch. That is the common clutch to all the transmission speeds you mention. Any transmisison speed selection in a motorgrader requires 3 clutches to be engaged. The full clutch engagement table is as follows: - 1F - 1 6 7 2F - 2 4 7 3F - 2 5 7 4F - 1 5 7 5F - 1 6 8 6F - 2 4 8 7F - 1 4 8 8F - 1 5 8 1R - 3 6 7 2R - 3 4 7 3R - 3 5 7 4R - 3 6 8 5R - 3 4 8 5R - 3 5 8
If there is a leak internally it would probably be behind the control valve in one of the many oil ports Maybe a seal?
I would personally suspect the #1 clutch piston seal just starting to fail. Did this problem appear out of the blue or has it slowly got worse over time..? What oil are you using in the transmission system..? You can have a bash at resealing the control valve manifold ports if it makes you feel better but I think at the end of the day you will still be pulling the transmission. I hope I am wrong.
The problem seemed to happen really quick after the blade set for about a month. CAT changed the transmission oil and filter about two and a half months ago, I know it's a CAT oil in the transmission
Each one of the clutches has a pressure test port. Can you rig up a gauge and check what you have cold and hot. You will need about a 500 psi gauge. These transmissions can also be air pressure tested at the end of each countershaft on the back of the trans.
hi, what is the serial prefix. the trans control could have either a manual modulating valve (cable operated inching pedal) or electronic proportional control. the test procedures are slightly different. see image below it is a good idea to check pressures at each station as mentioned in an earlier post, generally if your pressures are good you can rule out the electrical side of the problem and concentrate on any mechanical issues (except for calibration issues) if your pressure to the clutch station is low it could indicate internal leakage to that clutch (no 8) a good indication of this is to check your transmission lube pressures in each gear position in an earlier post you suggested that you changed coils to a different station. was there a build up of rust or corrosion on the stem of the valve? this can affect the operation of the modulating valve Did you also change the modulating valve as well? in the manual modulating valve any station can be changed with another station in the proportional control only the top three can be interchanged in the earlier manual valve each solenoid when engaged should have 24V at the solenoid (this would be solenoid B on the above image) the proportional control uses a PWM signal .you can back probe the connector at the solenoid and check its duty cycle compare it with one of the other known good stations there will be small variations because of differences in calibrations between clutches ( this is solenoid 1 on the above image ) if you disconnect the solenoid from the harness on the later machines this should give you a fault code also if you bridge the connections this will also give you a fault code if it does it is usually an indication that the harness to the ECM is OK Hope this helps regards Mark
Have you checked the transmission screens
The serial prefix is APM
Before coming up with the trst procedure - a question. There is a Serial Number break in the APM series. Is your machine S/N above or below 2656..?
Below 02921
That doesn't really help. I need to know if it is above or below 2656. The exact Serial Number does not matter.
Hey Nige I don't understand the question
You gave us the Serial Number prefix of the machine - APM. On the VIN plate there will be a 5-digit number after the letters "APM". I don't need to know what the exact number is, just is it lower or higher than 02656..?
Hey Guys The screens are clean
Sorry about the delay Nige I got busy trying to wrap up a project for a customer and then to get a look at the screens The answer would be my serial number is higher than the number you gave me
OK then ......... first you'll have to remove the guard from over the top of the control valve test ports. With the machine cold hitch a 600psi gauge to test port #1 in the illustration below and run it into the cab where you can see it while you are operating the machine. See how the pressure changes as you operate and as the machine warms up. The pressures will change as the clutch modulates (engages) but this is normal, you need to keep an eye on the pressure once the clutch is fully engaged. Of course if you are using a transmission gear that does not require #1 clutch then the pressure on the guage will drop to zero. My feeling is that the pressure is going to go down based on your description of the symptoms. The specification for clutch #1 is 329+/-14psi with the transmission oil at operating temperature - you may well measure a higher pressure than that cold.