973C calibration problems

[cb75]

Working on a Cat 973C track loader S/N 3RZ00740. Having one heck of a time getting the track speeds calibrated/synchronized properly. My question has to do with the max track speed calibration in submode 17, the monitor/ecm will not let me lower max track speed below 10.9 kph. Book says to lower it to around 9kph. Everytime i try lowering it I get the not accepted symbol. I can get the rest of the settings fairly close so the machine runs/tracks/operates pretty decent in "turtle" mode, but it is still kinda herky jerky when steering/ changing direction. I've also noticed that trans pilot pressure is about 70psi higher on the right side vs left (according to ET). Can't find any info on adjusting these pressures in the service manual. I've had success calibrating other machines in the past but it's been afew years since I've fooled with one. Reason for needing calibrated is pumps and motors were sent out for re-sealing (3 of the 4 were leaking) Any suggestions or advice would be greatly appreciated... Thanks for taking the time to read my post..hope it makes sense as i dont type to well or post much but have gotten a wealth of knowledge from the forum. Many Thanks

 

[mikebramel]

Do you maybe have an old software version that is not compatible

 

[cb75]

Do you maybe have an old software version that is not compatible

I'm not sure I understand your question. The pumps and motors were sent out for repair while we overhauled the engine, radiator, pump drive etc. The ECM is original. Did find some o-rings and back-up rings missing from the synchronization valve cartridge which caused alot of tracking problems, but it has been repaired/ replaced with a new valve, all new seals thru out sync valve and ecm manifold. The ECM or software was never messed with.

 

[mikebramel]

Sorry, i really know nothing about your problem. I was just assuming that the version of the software that you are using to interface with the machines computer does not have the capability of adjusting that parameter

 

[cb75]

Sorry, i really know nothing about your problem. I was just assuming that the version of the software that you are using to interface with the machines computer does not have the capability of adjusting that parameter

Oh, the calibrations can be done onboard the machine without using ET. I thank you tho for taking time to read and respond to my post.

 

[Bob/Ont]

Oh, the calibrations can be done onboard the machine without using ET. I thank you tho for taking time to read and respond to my post.

CB, I have limited experiance with C models But have shared many bad experiances calibrating a few. Most of this resulted from poor adjustments while rebuilding. Our rebuild shop will not touch them anymore and we use Cat Exch, they are setup good and calibrate with less trouble. You should be callibrating the tracking in Rabbit, not sure if you did.
Will your machine display the travel speed from both sides on the dash or just one side. Had an older one like that the RH speed sensor was not wired in. I made a harness to switch the sides to the dash when I wanted to see them. That way I could roughly sync the speeds with the sun gears out while sitting in the shop. Syncing in speed 6 Rabbit is quite a ride with out a large vacant lot. Most of the speed change is with the motors, pumps do the first third I believe. There is a speed chart/graph with speed for each of the six positions. If you take the pilot pressure line off of the motors you can chart the speeds and then it flat lines with motors at max angle. That shows the pump out put. Then hook up the lines to the motors and see the rest of the speed graph. There is an adjustment in the motors to get the graph right. It's in the manual.
Later Bob

 

[cb75]

Bob, Thanks for the reply. I have been attempting calibrations in "rabbit" This loader displays travel speeds for left and right tracks but in seperate submodes. When in cal/ sync mode the speed displayed is the difference in speeds from right to left and you're suposed to get that number as close to zero as possible.

I'm starting to think my problem is like you said, stemming from the adjustments made while rebuilding as I had to adjust neutral on 1 pump after we first started machine up after re-asembly. And you got that right about synching speed 6! Wow what a ride! Thats why I've tried the adjustments with machine up off the ground. I may try as you said and remove the axles and try again in the shop. I am currently studying the speed chart in the manual and will give it another go tomorrow as I was unable to work on it today.

 

[Bob/Ont]

Just a heads up CB, any time you pull the sungear shafts, pull the thrust slugs out of the outer plates, they can fall into the planets and cause major destruction, as can a failes planet pinion shaft bearing. If the planet pinion bearings fail the teeth can come down tip to tip if pushed and break the ring gear. The sun gear will keep them in mesh if installed but when removed the planet gets out of sync.
Later Bob

 

[cb75]

Hey Bob, By "thrust slugs" do you mean that round disc that is behind the check plug? I'm pretty certain the bearings are all in good shape as we just went thru the right side final and the left was apart for a new duo-cone seal within the last 50-60 hrs. I didn't get to work on it Friday as we had other break downs and more pressing issues to deal with, will most likely be back on it on Monday. Thanks for the heads up.

 

[Bob/Ont]

Yes that's it CB, they are a press fit at first but the bore tends to crack in four places and they get loose.
Later Bob

 

[cb75]

Hey Bob, haven't logged on to the forums in quite some time. Wanted to let you know what the problem ended up being...it was a bad displacement valve on the LH track motor. Took it apart and saw absolutely nothing wrong with it, but swapped it with same valve on RH motor and problem switched sides. Ordered and installed new valve and machine calibrated without a bit of trouble. It's run over 1000 hours since without any issues. Thanks again for your help...CB

 

[Bob/Ont]

Thanks for coming back CB.
Later Bob

 

[Nige]

I'll second that. There's nothing more irritating than having all sorts of suggestions made as to what could be the root of a problem then the OP doesn't come back at the end of it and tell the forum what finally fixed it. Kudos CB.

 

[powerjoke]

yup!