Hi guys, I have a 289D, serial 0289DVTAW01488. The symptoms I have are when the hydraulics are hot, it really doesn't show up in the winter or for the first half hour of operation. When traveling in low speed, and shifting into high, the machine will slew hard to one side, you have to input hard stick correction to compensate. When shifting back down into low gear, the machine slews hard the other direction. After shifting into high, it will straiten out, but only after rather prolonged correction. Once it is running straight, it will not run as fast as it ought to, up to 3mph slow. I was told by the dealer I bought the machine from that this is a common problem relating to a swash plate issue in the drive motors, which Cat has remedied with a service bulletin and updated part. Basically the problem is a lazy shifting side and the PCM compensating for reduced track speeds by slowing the other side's flow. What I am looking for is either opinions on the cause of the problem, or information on Cat's updates. My understanding of hydraulics is limited, so I am little fuzzy on what the swashplate is doing and how, (and what it isn't doing, in this case).
Looks like two speed oil path leakage.
I am not super familiar with reading serial numbers on the dealer stuff, but is my machine covered by that campaign? My machine is TAW 0, it says TAW 1 and up. ?
TAW1-Up (aka TAW00001-Up) is Cat shorthand for "from first machine built". Cat never uses the zeros in those circumstances. More specifically the document covers machines up to S/N TAW02847 so your machine is included. To be clear it is only a Service Magazine covering an in-production improvement, not a factory recall program.
So being as the machine is covered under that update, what exactly does that updated seal kit resolve? What are the symptoms it remedies?
All dealer support ($$$) ended in 2017 for that seal leakage. Upon reading further, the leak goes external? Maybe that ain't the issue? Is there a way to measure 2 speed pressure or leakage?
If there is swash plate letter/ update, I don't have that deep of access.
There is no real external leakage, and I don't really have a way to measure hydro pressures.
So I talked to a guy locally who deals with the Cat track loaders a lot, and he told me that Cat updated the swashplate springs, apparently they get weak and cause the symptoms mine has. So for lack of any better idea as far as diagnostics go, I got the kits he recommended, Cat 487-6227. I am debating whether to replace the swashplates myself or just take the final drive off and take it to somebody smarter than me . . . is there a service manual procedure for tearing down the drive motor, and maybe a parts diagram?
I thought the swashplates were in the pumps....??
They are, but the pumps are on the back of the final drives. I haven't torn it down yet, but I am told that the final/motor assembly has to come off the machine in order to service the pump. Just from glancing at it I would think that is how it will go, there isn't much room between the final and the machine frame.
Maybe we are talking at cross-purposes here. These are what I refer to as the drive motors/final drives. The 2-section hydrostatic pump (2nd illustration) is mounted on the back of the engine flywheel and located through the firewall almost directly behind the operator seat. Attached the pump removal procedure and parts breakdown in case they are any use to you.
Sorry, that is my fault, I was thinking in tunnel vision and thought pump when you said motor. There seems to be a swashplate in the drive motor as well, I believe this one is related to the two speed. The guy here sent me a picture of his Cat parts screen, showing the part number in question.
It is related to the 2-speed. I assume this is the one the guy you mentioned above (Post #9) recommended to change, because that's where the 487-6227 Kit is used. Come to think of it I'm the one getting confused with another thread of a CTL that started moving on one track immediately the engine was started. The only way to stop it was to apply a steering input. That one turned out to be weak swashplate springs in the pump allowing it to drift off centre. I was was mixing up the two threads. Sorry, as you were....
It's easy to get confused with this setup. The piston pumps have swashplates which act normally like any other variable displacement piston pump. The piston motors on the single speed machines have a fixed plate instead of a swash plate. The piston motors on these two speed machines like yours do have a swash plate and their only purpose is to control the two speed function. I admit it's a problem with these drive motors... I wouldn't say its that common. There has not been any update on that swashplate spring that I can see. The O-ring update above I don't think will help you unless your drive motors are leaking oil. There has been flushing spool updates which can sometimes fix the issue, 581-4919 spool is available for your machine, I've heard good reports that it has fixed straight line tracking issues but... I tried this on the last two occasions (and the exact same symptoms as yours on a D2 series machine) to no avail. Eventually resolved by replacing the drive motor. Yes, but skip to page 4 on this thread first... HeavyEquipmentForums You'll find you can only go so far without some kind of fabricated stand and 3000 ft lb torque wrench, but you should be able to install the 487-6227 spring kit without going that far.
Well, I don't have a 3,000lb torque wrench, and I don't really have the time or ambition to fabricate a stand . . I do have a shop press, so I should be able to bypass the sketchy Home Depot clamp setup going on in that guy's pics from the burn rebuild. I have done enough wrenching to be really wary of throwing parts at the machine because somebody said "Oh, change such and such part and it will fix it". The trouble is that I don't have a real deep knowledge of hydraulics, so diagnostics is a bit sketchy. The explanation I got from the guy who told me to change the swashplates was that the spring gets weak. He said the new springs are larger than the old ones. I am not sure, but I think he said that Cat would throw a motor at it, but that the problem is the swashplate, and that is a much cheaper fix. At the end of the day, for lack of better ideas, I am thinking I will just take the motor apart and see what is going on in there, it would just be nice if there was some sort of procedure to get a better idea of what was involved first.
https://avsmanual.com/i.caterpillar/i05926265/ You may have to use Google translate, and each blue text needs clicked on.
Here's the D&A for the drive motor once you get it out.
Thank you, that is quite helpful
Looks like I am going to have to subscribe to Cat SIS sometime in the near-ish future ...
Absolutely. Truth is it's a risky repair for a dealer to warrant for the next 12 months. I think you'd be better off trying to get hold of a service manual for your machine. Also in an ideal situation you would need a computer with Cat ET to perform a pump/motor solenoid calibration once repairs complete. This should definitely be done if you end up replacing the drive motor.
Cat Publication UENR3725. Here's one on CD for $650. (Usual price $735). A paper version goes for $1050 new, and I can't see anything used on eBay at the moment. https://www.ebay.com/itm/313601047239
Trouble is I have 4 Cats, and this track loader is the newest. (And seems to have the most problems) I just looked and it looked like a SIS subscription is $700 a year. Kind of pricey if you aren't doing customer repair work, but I don't know, might be worth it. Sometimes I wish I had kept my b3 track loader . . .
Comes down to how much repair work you want to do yourself I guess. Down here $700 would get you 1 or 1.5 dealer callouts depending on the issue. Then you've got the issue of Cat ET, which depending on how old your 3 other Cats are, usually goes hand-in-hand with Cat SIS when troubleshooting.
How much do you buy per year in parts from your dealer.? Usually you can leverage that "spend" against a free SIS subscription, which might be limited to only your 4 machines instead of everything, but at least it would get you the parts/maintenance/service info you want.
So I have some answers on this machine, at least preliminary answers. We tore the drive motors down, and found that the swashplate kits Cat 487-6227 are in fact an updated design. The spring is longer, and is a double spring rather than a single spring. In process we also replaced the seals with the updated design that Heymcall mentioned earlier in the thread. I won't really know if this has conclusively fixed the problem for a few more weeks at least, as I will have to be able to work the machine enough to get the hydraulics hot. Too much mud and snow for doing driveways right now. I will report back once I can work it, but there were enough obvious issues on the right side to make us pretty confident that we are on the right track.
The problem will be on the drive motor that is lagging... ie when switching from low to high and the machine suddenly tracks left, the problem is the left drive motor, and vice versa. Did you end up undoing the very tight nut? If so please share how you did it. Apologies... on second looks, Cat does mention the 487-6227 Swashplate Kit is updated, but makes no mention of how. Your Cat guy is on the money.
The right side was in worse condition, and it was the right side that was lagging. We did not go as far as that big nut ...
Just to wrap this up, we have had a chance to work the machine now, and the problems seems to be fixed.
Thanks for reporting back. This is invaluable information.
Most of the time when I change a drive motor the new motor is more powerful so it pulls to the side with the new motor so I have to adjust the swashplate on the pump so the machine can track / drive straight I change drive motor oil almost on the daily the majority of the gear oil is very dark and almost always smells burnt From my experience the drive motors fails a lot due to excessive dirt build up on top and around the motor causing they to overheat and in other cases the seals fail inside causing damage and when worked hard they do get pretty hot based off outside temperature Caterpillar recommends changing the gear oil every 50 hrs due to the fact that you can never get all of it out therefore the oil is always contaminated
I dunno know. The gear oil gets changed every 500 or more hours here on my 10k hour, original finals, TL150 machines. I try to change them every 300 hours....but, every 50 hours is ridiculous, and unbelievable.
Cat isn't 50 hrs, I think it is 500, might even be 1000 but I am not looking at the book at the moment. It is not 50, that's for sure.
You're right. The Cat O&M says every 500 but perceived wisdom seems to be change the oil every 250 when the engine oil is changed, basically because it's such a small quantity per final drive and the finals are under so much stress.
Your 100% right In the sm or wsm it does not said ever 50 hours but cats personal recommendations are 50 hours
50 hours, we can do that in one busy week during the summer. Pretty sure I am not dumping the finals every Sunday afternoon, and neither is anybody else in their right mind. Truthfully, if everybody actually changed the final oil at 500 hours they would be just fine.
Agreed, especially if they used the right oil..........
It is some kind of fancy synthetic stuff they gave me in quart bottles, not supposed to use the FDAO that's in the older stuff.
C & D-Series machines specify synthetic GO 75W/140. 75W gear oil is approximately equivalent to a 15W crankcase oil viscosity so if you put it in engine oil terms a 75W/140 GO is somewhat equivalent in viscosity to a 15W/60+. Older stuff appears to specify TO-4 up to SAE30 depending on ambient temp. I would've thought FDAO being SAE 60 crankcase (almost equivalent to a 140 mongrade gear oil) would be too heavy a viscosity when cold.
I think the engineers just play eeny, meeny, miny, moe when designating a final drive oil.