973C straight drive in reverse

[BRHol]

Hello
I have a problem with a Cat 973C - 3RZ serial number. In reverse driving machine pulls to the left. It seems the left drivemotor turns slower for some reason.
The problem is only in slow driving, speed lever halfway and full throttle. When the speed lever is all the way open, there's no problem and machine drives straight. The rabbit an turtle modus makes no difference. There are no fault codes in the ECM
The 4x Solenoid valves of the steering at the ECM manifold are replaced for new ones. I tried to calibrate with the 3 switches under the armrest the submode 1-9 and 15&16. In forward drive it is okay, but calibrating submode 15&16 with the tracks in reverse driving makes does not solve the problem. Calibrating submode 1-9 (engine off) goes well.

Anyone who can help?

regards Bram

 

[BRHol]

The transmission override solenoid valve is also replaced for a new one.

 

[Nige]

Do the attempted calibrations in reverse for Modes 15 & 16 throw up any sort of error message.?
Are you also attempting to calibrate the maximum track speed in Mode 17.?

 

[BRHol]

No, only when i'm entering calibration mode the red light of the Hydrostatic Transmission begins flashing immidiatly, that's in all modes of calibration.
I'm attending to calibrate maximum speed mode 17, but i need more space to drive...
I thought this may not solve the problem because problem is only in slow drive, or am i wrong?

 

[Nige]

I thought this may not solve the problem because problem is only in slow drive, or am i wrong?

I'm sorry I don't know.

I'm attending to calibrate maximum speed mode 17, but i need more space to drive...

Is putting the machine up on blocks an option.?

Do you have any Active Diagnostic Codes at all on the Monitor display.?

 

[BRHol]

Thanks!

Do you have any Active Diagnostic Codes at all on the Monitor display.?

Before starting the diagnose work there were the following codes in memory: 0299.13, 0349.05, 0134.07, 0135.07 but i think that was before replacing the 4x steering solenoids (I didn't replace them, it was done before i started diagnosing). after clearing the memory there was only one time code 0190.08

Is putting the machine up on blocks an option.?

That's a good idea, I'll try that.

 

[Nige]

after clearing the memory there was only one time code 0190.08

Is that Code still Active.? Because it's for the engine speed sensor, and I would bet that if that Code remains Active then attempting track speed calibrations might be more than a touch difficult.

Also you might find an electrical schematic useful. I have one I can send to you.

 

[pittsburgh cat man]

First never had real good luck calibrating off the ground. Second the tran light will flash as soon as you as you enter calibration modes. Third calibration for straight travel must be done in all 6 speeds forward and reverse

 

[BRHol]

Is that Code still Active.? Because it's for the engine speed sensor, and I would bet that if that Code remains Active then attempting track speed calibrations might be more than a touch difficult.

It's not active but I'll check if the sensor and rpm of the motor. Thanks for that!
If you can send me the electrical schematic, that would be great. I'll send you a pm for my email

 

[Nige]

If you can send me the electrical schematic, that would be great.

Check your message inbox.

 

[BRHol]

First never had real good luck calibrating off the ground. Second the tran light will flash as soon as you as you enter calibration modes. Third calibration for straight travel must be done in all 6 speeds forward and reverse

Hello Pittsburgh cat man
Thanks for your comment!
I'll do the calibration over again in the open field, calibration all 6 speeds is a valuable advice. I didn't know and I read over it in the manual
I'll come back later

 

[BRHol]

I did the calibration in open field in all 6 speeds and in submode 17, max track speed.
The calibration was totally wrong, in particular the max speed in submode 17 was wrong. Calibration is now good so far. After calibration i tested him in the field. Immediately there came some Active Diagnose Codes on the steering valves. And there's some hydraulic noise coming from under the cab, when steering pedal is pressed more than half way.
The Diagnose Codes are: 134.07 & 135.07 & 469.12 & 470.12 & 471.12
The charge pressure is 2800 kpa

any ideas?

 

[Nige]

All those Codes refer to the left and right FWD/REV steering solenoids.

FMI07 is "Not Responding Properly". This occurs when an electronic control sends a command to a mechanical system and the result is not within the acceptable range.

FMI12 is "Failure". This occurs when a smart device (such as an ECM) has determined that a device has failed. In this case it would be a solenoid.

 

[Nige]

Here are the other three procedures.

 

[pittsburgh cat man]

I think I would check harness funny for it to call out all solenoids

 

[Nige]

I think I would check harness funny for it to call out all solenoids

That would be my thought also. It seems strange for 3 out of 4 solenoids to go AWOL at the same time.

 

[pittsburgh cat man]

I was thinking you need to go to engine off calibration and do the steer pedals again it’s best to do the pedal up with your foot off the pedal and make sure pedal is all the way down when you accept it

 

[BRHol]

Thanks!
I'll check the harness and solenoids, it looks quite well but i'll check it more carefully.
If that doesn't solve the problem, I'll do the calibration all over again.
Is it necessary to Reset Calibration in submode 13?

 

[pittsburgh cat man]

Don’t do that you’ll have to start all over again

 

[BRHol]

Don’t do that you’ll have to start all over again

Ok thanks, saves me a lot of time