Cat 140m3 awd 5th gear clutch slipping

[mattyg]

Hi my machine has about 4600 hrs. while traveling up a hill in 5th gear i lost speed but my rpms didn't change. this has happened 2 times to me becuae i thought i was making it up. no codes or lights have come on. any thoughts? thanks.
serial is cat0140mvn9j00310

 

[Nige]

Drain the transmission oil and remove the suction screens (there are two of them) for inspection. If the clutch is starting to fail there should be evidence of burned friction material in one or both screens. The procedure for removal & cleaning the screens is in your Operation & Maintenance Manual.

 

[Nige]

Just in case you were not aware, each speed in the transmission requires three clutches to be engaged. The table of clutch engagements is in the attached photo. My suspicion is on clutch #6 that is used in 1st & 5th speed forward plus 1st & 4th speed reverse. Try a test by putting the machine up against something solid in 1st speed forward and then slowly release the inching pedal. Does it stall the engine.?

You could also try to duplicate the symptoms that you are experiencing in 5th speed forward in 4th speed reverse.

 

[mattyg]

thank you Nige, I will keep this updated with what i find. cat came and took an oil sample so i should have those results soon.

 

[Nige]

while traveling up a hill in 5th gear i lost speed but my rpms didn't change.

Try going up a hill in 6th speed forward. Does the same thing happen as happens in 5th speed.?

 

[mattyg]

the machine was able to spin all 4 rear tires in first gear at an idle. i am taking this as good news. I still have not gotten my oil sample results back yet.

 

[Nige]

the machine was able to spin all 4 rear tires in first gear at an idle. i am taking this as good news. I still have not gotten my oil sample results back yet.

That indicates #5 clutch is working OK, so let’s investigate the high range clutch that is used for speeds 5 thru 8 forward and 4 thru 6 in reverse.

Try my suggestion of attempting to climb the same hill in 6th speed rather than 5th. What happens.?

 

[mattyg]

I will try that when i am around some more hills. Thank you

 

[Nige]

If 6th speed forward produces too fast a ground speed you could always try it in 4th or 5th speed in reverse. Both of them still use the same high range clutch.

 

[mattyg]

Quick update, the oil sample came back good.

 

[Nige]

Would you like to post up a copy of the results.?

 

[mattyg]

I need to learn how to post an attachment of the oil sample. I was just working around some hills and the problem still happened in 5th gear forward but i was able to back up the hills in 4th gear no problem. Could this be an issue with solenoids? thank you

 

[Nige]

I need to learn how to post an attachment of the oil sample.

Use the “attach files” paperclip icon on the bottom left of the screen.

 

[mattyg]

lets see if this works

 

[Nige]

lets see if this works

It did, and the oil sample is as clean as a whistle. The only question I have is when was it last changed because apparently someone is not marking the samples with the "hours on oil" when they send them in. According to the results (see "meter on fluid") the transmission oil has never been changed - ever...!!



But that's by the by, there is nothing in the sample that indicates any sort of wear issue be it clutches or metal.

 

[Nige]

I was just working around some hills and the problem still happened in 5th gear forward but i was able to back up the hills in 4th gear no problem.

Go back to post #3 and look at the clutch table. The High Range clutch is used for speeds 5 thru 8 in FWD and speeds 4 thru 6 in reverse.

The fact that at the time you have no drive in 5th speed forward but you have 4th speed in reverse with no problem indicates that the High Range clutch is apparently working fine.

This is looking more and more like something electronic.

 

[mattyg]

here is the previous oil sample. oil had about a thousand hrs on it. Thank you for your input. Matt

 

[Nige]

On that machine the transmission oil should be changed every 1000 hours or 6 months, whichever comes first.

 

[Nige]

here is the previous oil sample. oil had about a thousand hrs on it. Thank you for your input. Matt

Again the sample was totally clear. The more I see if this the more I am convinced that the problem is on the electrical or electronic side. I think the next step should be to get ET hooked up to it and download a Product Status Report (PSR) in pdf format. Upload that when you have it.