Hi I have a CAT 950H and it gives heavy jerk with metal sound when brake is released while moving, i serviced front differential, front drive line is replaced. Any body there who had same problem and has any solution please help....
Are you using the correct anti-squeal additive in the axle oil..? You said that you "serviced" the front differential. What exactly did you do..?
First i felt like the sound is from front differential so i opened it and found 2 sun gears of spider is cracked and right side big ring gear was cracked too so i replaced and oil i use is 80 w 90 coz my machine has clocked 20000 hrs so i thought thick oil will be better coz of increased clearance after 20000 hrs.
You'e fooling yourself on the oil. 80W/90 EP oil is exactly the same viscosity as what the manual recommends which is SAE50 TO-4. They are measured on two different viscoisty scales which is why the numbers come out different. EP oil will rot the silicone rubber in the Troic Rings of the wheel seals, so be warned. I think a disassenbly of the brakes might be in order to see what sort of a state they are in. Remember that the brakes share the same oil as the differential. For more "how to" information regarding the brakes, post the machine Serial Number.
My machine serial no is. JJAD00937. U mean i should stop using 80 w90? Ok, but why the jerk ? Tell me something regarding jerk....
Inspect the brakes, that could be where your problem is
Thank you for replying...but canu u please explain..like how? ...
Yes - you should use an SAE50 oil meeting Cat TO-4 specification plus 0.5L of 1U-8981 Oil Additive in each axle. That is an anti-squeal additive for the brakes. Disassemble the brakes and I'm reasonably sure that you will find the reason for the jerk. Most likely with 20,000 hours the friction discs are worn out and what you have no is metal-on-metal grabbing which will cause a jerk. Note: To disassemble the brakes will require the complete axle to be removed from the machine and stood in a vertical position. The brake assembly has to come off in an upwards direction. Then after reassembling the first brake pack the axle should be turned with the other end facing upwards and repeat the process for the second brake pack.
I did the same process , full assembly was removed and friction plates are almost ok..now ?
All you said previously was that you "opened the differential", not "I disassembled the whole front axle including the brakes and found the friction discs are in good shape". I know that the differential can be removed from this particular axle without complete disassembly, so what was I to assume from your statement..? Please give good information if you want assistance to save us all time. In that case, change the oil for 80W/90 EP to SAE50 TO-4 and use the anti-squeal additive I mentioned above. See where it gets you. A question. Has the jerk got worse over time or did it just appear suddenly..? Are you sure you found and replaced all the damaged parts in the front differential..?
Exactly u cant open only differencial in CAT 950H( in our country the whole thing is call differential) sorry...
Attached is the pages on changing the oil. Scroll down to the last page and read item #6. I know from personal experience on other Cat loaders with these wet brakes if not using the additive it will sound like things are very bad inside the axle. Then again it is still possible there is a major problem but I would not even think of trouble shooting it till you put correct oil and additive in the axles!
I removed the front drive line to check it gives the same jerk and sound on removing rear also same thing so i m thinking of servicing the transmission,can u help me with transmission service manual?
My Deeres will do that when driveshaft slop is excessive. On my Deeres, it's usually the front slip joint (splines), but ocassionally, I'll find a worn out universal joint.
Diagnosing symptoms is always a lottery. Is there any chance you can video the loader while it is making the noise and post the video to Youtube then link it here..? Also even if you remove either the front or rear driveline (I assume you mean drive shaft.?) you still have the brakes holding on the axle where you removed the drive shaft. So when the brakes are released, even if there is no drive shaft attached to the axle, you could still get symptoms. As Hmc said above, inspect the drive shafts carefully to ensure that the sliding joints don't have excessive play in them.
My staff has sent me some videos after removing both drive lines, i m attaching links here. My site is around 500 oks far so i ll be going tomorrow, will update til l than check the YouTube links...
I understand the difficulty especially when you are also not there with the machine. Were the first two tests in the videos made with both the front drive shaft and the rear drive shaft disconnected..? The first two videos I think both shafts must have been disconnected but I'm not sure how they were stopping the transmission output unless it was with the parking brake. It's hard to see in the last video looking under the machine whether or not the rear drive shaft is connected, although it appears to be because the rear wheels are moving. Maybe reinstall all the drive shafts and take another video..?
No its ino parking brakes, they were doing it with forward and reverse gear shifting .(F n R switch)
In that case definitely install the drive shafts and take another video. I'd like to see how much the transfer case output flange moves when shifting from F->R and vice versa. Also has anyone had a look at the contents of the magnetic screen for the transmoission suction..? See the attachment for the location on the rear RHS of the transfer case. What type of oil are you using in the transmission as a matter of interest..?
Yes! very important to pull that magnetic screen to see what if anything is on it! That should be a first step before going any further! The following are several questions I might be asking if I was there in person or things I might try myself. I did a quick look back in this thread and may have missed it but can you say if this is a new problem? Or is this a new machine to you and it has done this from the first time you touched it? If this machine had been working fine without this noise how did it first appear? Did it slowly get worse or was it working nice and smooth then out of nowhere it started making this jerk/noise? Same operator and job or new guy who never ran a machine before? Does it seem nice and smooth when driving along down the road and only time it makes the jerk/noise is when stopping and starting or changing directions? How about if say you are driving in 1st gear and shift to 2nd then to 3rd? Does it shift smooth from one to the next? While drive shafts were out did anyone try turning the yokes to the front and rear axles to see if they had about the same free play/back lash? How about with wheels blocked and parking brake released, did anyone try working the output shaft back and forth to feel free play in transmission gears? Not saying any one of these questions will give a positive answer to the problem but might help eliminate something or raise another question. One more thing does anyone else think this machine sound like it is idling fast? Hard to tell listening to the videos. Does it have a tachometer? Just checked SIS and it should have one. So what RPM is it running at at low idle? One more thing I looked in a trouble shooting chart and found reference to Jerky shifting: Problem: Clutch engagement is sudden. (This symptom causes jerky shifting.) Probable causes: 1. Modulating valves (5) , (6) , (7) , (8) , (9) , (10) need to be calibrated. ReferenceFor additional information about calibrating the modulating valves, refer to Testing and Adjusting, "Calibration and Programming". ReferenceFor additional information about calibrating the modulating valves, refer to Testing and Adjusting, "Fill Time for the Transmission Clutch - Calibrate". 2. Modulating valves are unstable. 3. A speed sensor has malfunctioned.
Yes i had seen the magnetic screen last time had been to the site and dint find anything suspicious and i use CAT oil ...
1. Yes it started and problem gradually increased, 2. No new guy all are experienced operators. 3. Yes smooth when driving along the road the noise come only when the gear gets shifted or when machine takes off after brake is released. 4. Regarding idle RPM dont know exactly, i ll be going to the site 2moro and will check by the way what should be the idle RPM? 5. Clutch calibration was done by the cat service person and completed without any error. Thank you very much for your support..
Could you be a bit more specific about the type of oil you are using please. Also, can you find out if the SERV CODE icon is lit in the Monitor Panel. This panel is located in the upper RH switch panel. See below - Ref #36 Here's a thought from left field........... Has someone switched off the transmission neutralizer..?
Another good idea, one which is someone familiar with the machine might spot in the first few seconds!
We have three of them, and it's something that the numptys who get employed to run them appear to be able to do with monotonous regularity..........
We tried both, neutraliser active and neutraliser not active. Same condition.
SAE 30 c4
I'm not familiar with that oil. Do you mean TO-4..? Back to my suggestion earlier of reconnecting all the drive shafts and re-shooting the video.
So was this calibration done in an attempt to solve the problem? Or was it done for some other reason. Did this "cat service person" do anything else like checking something or adjusting or replacing something? Or have any other thoughts? Agree with Nige on reassemble and re-do the video and show us the RPMs it is running at while doing this jerky stuff.
Clutch fill calibration was done to solve this problem by cat service person... And nothing else is done...