Hello, have a 950F series II loader that I've been having some transmission trouble with. The last day it was working, the operator was working the machine for about 6 hours in one to two hour intervals then letting it sit for about 30 minutes or so. All the work that the machine has done for the past couple weeks was in first gear other then about a one mile drive from and to the work spot at the start and end of the day, which he would use 3rd and fourth gears. The operator said that the loader worked fine all day in first gear, but when he went to drive it home he felt that it lacked some power in the higher gears but thought that maybe that was because the drive is slightly uphill in some spots. When he went to start the next day, he figured that something didn't sound quite right but thought that since it was cold that morning that possibly he just needed to drive it a bit to warm up the oil. As soon as he got it into 3rd gear the loader started lagging and engaging and disengaging the transmission in about 4 second intervals and lost most of its drivetrain power in all gears. He managed to limp it back the the spot where it was parked and shut it off. I pulled the filter out and the oil was a dark brown color, almost like muddy water. The filter was also dirty and has a black gummy like substance stuck in it, and a couple of very fine metal pieces stuck in the filter here and there, but you can not see them unless you look at it in the right lighting angle. Running a magnet over the metal areas does not pull the pieces out of the filter. The transmission pump was replaced about 300 hours ago in the machine and the filter had not been changed since then so those filings could possibly be from the break in of that pump. The operator was checking the transmission oil daily before use and said that about a couple weeks ago the oil on the dipstick seemed to be slightly darker on the first couple inches of the dipstick but the rest was clean and clear. He then mentioned that since then he has not noticed that the oil has gotten any darker on the dipstick. He also mentioned that he has pulled the dipstick a few times after doing some harder work with the loader to feel the oil temperature on the dipstick, and said that the transmission case was too hot to touch but the oil off the dipstick was hot, but you could hold your fingers on it. The oil also appeared clear when looking at it. Talked to one mechanic I know that works with heavy equipment and he figures that the oil was discolored because the clutch discs in the transmission are falling apart, and that the transmission is on its last legs, but he did not look at a good sample of the oil or at the filter. What does everyone here think? I will attach a picture, although not the best, of some of the filter that I pulled out. Thanks
Filter picture
Take a look in the transmission pump suction screen/magnetic filter #4/#6. Post photos of what you find. You may have to drain at least some of the transmission oil first. Also please post a Serial Number. It helps when looking for technical information. The illustration below is from a 5SK manual.
An SOS oil sample kit is roughly half the cost of a filter these days, that's the first thing I'd do. Even if it only eliminated contamination as a possibility. You'd need a clean sample from the running machine to say much, and a history would be far better, but it's still cheap and easy.
Forgot about posting the serial number, 8TK01217. I completely drained the transmission oil, which is how I found out about the oil condition. Have not pulled the screen as I don't have a gasket to replace. Have to wait a couple days to get some oil from Cat so could order one in the meantime. Can the filter be pulled out of the access hole from underneath the loader?
Agree with Delmer. Get a sample and have it analysed. Make sure they do a Particle Count while they’re at it.
I will take a look into the fluid sample. A couple questions about doing that though: 1. When I received this loader it had a fresh transmission oil change done on it. Has had about 400 hours put on it since then (Around 17,800 hours total now). Problem is, I do not know exactly what type of oil the place it came from put in, and I haven't been able to get a hold of anyone there that would know. Is this an important thing to know? Seems odd to me as they had been a fairly big equipment dealer before for many years but now it seems like they have been wiped off the face of the earth, and I was only able to get a contact number because of a listing from a paper that I had saved years ago. 2. Since I have already drained all the oil out, how should I go about taking a sample of it? I put the oil in some pails with lids on them so it should not be contaminated, but how should I go about getting an accurate sample?
That doesn't sound hopeful, do you think they were on their way out and put $40 yellow and green buckets in a transmission like this? For Nige, that would be recycled oil that used to be marketed as "303" until they were sued, still marketed as not suitable for modern equipment, which is completely honest. I'd dip a clean glass jar into the oil pail, and fill the sample bottle with that. It won't tell much about the particles that dropped out, but you can find the big ones and examine yourself. The dirt contamination would throw off the results. That's what I'd do anyway. I'm sure somebody could tell the difference between "303" oil and the correct transmission fluid, but I'm not sure the info on an SOS is enough, or who to ask even.
I've come across the stories of "303" so in the vernacular - "I'm familar with it..!" It will be in the measurements of "additive" elements such as zinc, calcium, phosphorus, magnesium, and maybe sulphur. They will all be listed in the SOS report.
Thanks for the advice. Do you know if there is a part number for the SOS kit(s)? I won't be able to go to the dealer to pick up the oil and parts I need to get since the dealer is 130 miles away, so I will be sending someone else. Also, does anyone know if the suction screen in the transmission can be removed through the access hole cover on the bottom skid plate/pan, or do you have to drop the whole pan in order to access that?
There may be but if there is I can't remember what it is. I would suggest to call the dealer and ask before sending someone. Sorry, no idea. It's not usually the case on a wheel loader but there's always a first time.
Took a sample out of the pail and put it in a jar for when I get the correct sample bottle, but here is a couple pictures of what a cup full of the oil looks like.
OMFG, that’s horrible……. Does it smell burned, even a little.? You don’t need that oil analysed IMO, the colour tells you all you need to know. Pull the magnetic screen and inspect for burned clutch material. If you find it the transmission’s coming out.
Oil smells very slightly burn't, but it has smelled like that since I acquired the machine and it doesn't seem to have gotten any worse since then to me, but I could be mistaken. Here is my breakdown of pulling the filter screen and magnets out: 1. You do have to take the whole rear pan/bottom guard off to access the filter 2. Pulled out the filter and this is what appeared like before any cleaning was done:
As you can see, the filter is quite plugged. One thing I did notice though was that when I took the cover off of the transmission housing, I could not find a spec of rust on any of the bolt heads, and it appeared that where my socket took the paint off, that it was all completely clean and untarnished. This is making me wonder whether or not this filter has even been cleaned before?? If it has, it must have been done many thousands of hours ago or it is a coincidence that whoever did it last didn't take a chip of paint off of any of the bolt heads. Most very likely when the oil was changed at the dealer a few hundred hours ago they never touched it, and it doesn't appear to have been repainted. After that I took the magnets and rinsed them in some parts cleaner, and this is how the magnets appeared after being rinsed:
Next, I pulled off any pieces stuck in the filter or on the magnet and this is what I got. As you can see, I labeled what I found that was magnetic and what I could identify. Very odd that the metal particles made the leaf become magnetic; however that got in there I do not know:
And this is the fines that washed out of the filter. Hopefully this information will give you what info you need. Thanks
With my fortune teller's hat on, and based on all the evidence presented in the photos above, I predict a transmission rebuild in your short-term future. The plugged screen you found must have been seriously restricting the transmission pump suction capability. How long has the machine been in your ownership.? I'm assuming you don't have a maintenance manual for it but I suggest you should get one. They can be downloaded in pdf form for around US$50. FYI transmission oil in normal operating condition is supposed to be a light straw colour and perfectly clear & bright. Try this for starters though. Fit a new transmission filter (see illustration), refill the system with SAE30 TO-4 oil, and see how it goes. You have nothing to lose at this point, although I don't have particularly high hopes.
How many total hours are there on the machine.?
I'm waiting on some TDTO TMS to come, already put a new paper filter that I had in stock in the machine, just didn't have enough oil. The paper filter has about 200 to 250 hours on it since I changed the transmission pump on false diagnoses, where I put a new filter in. Never noticed any of these materials shown here in the filter at that time. I've had the machine for about 350 hours, bought from a relative who got it from the dealer I mentioned earlier and put about 60 hours on it, then decided he wanted to trade another loader he had and get a newer unit. Transmission oil was supposedly changed at the dealer just before delivery to my relatives place, so I have never touched the suction screen filter, in hindsight it appears that I should have because it seems unlikely that they, or anyone who owned the machine for many hours before them did. I usually don't operate this machine, but have a trusted operator on it. The times that I checked the oil on the dipstick here lately I couldn't disagree with him that the oil did appear a clear color, so maybe should have been pulling the filters more often, but again, hindsight. I was planning to change the transmission oil at 500 hours of use regardless. The operator mentioned that he never had any warning lights about low pressure showing, which does seem odd to me unless they are not working. Are those slightly magnetic pieces that I have shown in the large circle off of a clutch plate? Seems like they could be to me. Regardless of what, and to the advice of you and a couple other people I talked to, I am going to just put the suction screen back in and new paper filter and just run the machine doing some light work for a few hours, then pull the paper filter and if it is dirty, the suction screen again and see what's what. That is of course, if I don't have transmission trouble right away. Edit - About 17,800 hours total on the machine.
With 18k on the machine it's probably way overdue for a transmission overhaul if it hasn't had one already. Check the transmission Serial Number which may be on the plate in the cab or if not look where the arrow is pointing. It should be 5FK01695 if it is original. BTW I checked the O&M Manual and the first step regarding changing the oil and cleaning out the screen is "Remove the bolts that hold the transmission guard. Remove the transmission guard on the underside of the machine". The could explain why nobody ever removed it - too much work.
BTW if you want to get hold of an O&M Manual click this LINK , put SEBU6492 in the box and click the Search button. The image below should appear.
I am able to access the operators manual through the SIS platform, but can not access any service/repair information. Looked for two hours to try and find a serial number on the transmission, and couldn't find anything with the 5FX prefix. All I found were the part numbers that are on each piece, and one other number on the housing, 012 4 6789, which guessing by the number sequence means nothing. The serial number on the plate in the cab did match up with the transmission number you provided. Took one of the bolts out from the filter screen plate and cleaned it up with a cloth. Sure doesn't look like these bolts have been touched much or at all either then from me.
According to the illustration it should be on the LH side of the machine. It wouldn't surprise me to find that it is hidden behind a hose or some other component.
I looked on both sides, the top, the bottom, on other components, underneath hoses, etc. and couldn't find anything. The 012 4 6789 number was about a few inches to the left on the side where the transmission serial plate should be. I looked very closely on the sides of the transmission to see if perhaps the 5FX number is stamped into the housing instead of being on a plate, but there was nothing.
It wouldn't surprise me with c19k hours on the machine if the transmission was not original. Neither would it surprise me if a rebuilt transmission for a machine of this size class came from somewhere outside the Caterpillar network and was missing all identification marks. I've seen that before.
It did have the Cat part number on the side of it, see picture: On the RH side below the hydraulic pump, in about the center of the casting.
8E-4952 is the Part Number of the case and the MONUDR Date Code of its manufacture (21st January 1994) which corresponds with the build date of the machine of 31st March 1994. I'd say that is the original transmission but whether it has been overhauled already I would have no idea. Assume it hasn't would be my suggesion.
Thanks for the info. Still waiting on oil but hoping to get going in a couple of days. Hopefully it works but for sure no guarantees. If a rebuild had to be done, I don't know whether it would be worth doing or not? Do you figure that those pieces that are about a 1/4" to 1" long in the filter picture are/were a part of the clutch discs? Was hoping to get another couple hundred hours out of it so I could finish some projects that I bought it to do, then it would be delegated to some fairly light work around the yard here and there, but seems like that could be a pipe dream.
All that pile of "fines" material that came out of the suction screen is burnt up clutch facing material.
Ok. So, do you think the best course of action would probably be just to keep running it if it works fine and check/clean/replace these filters often? If one was to rebuild the transmission, would it be worse to keep running it until it fails completely? Would be nice to get at least another 50 hours out of it so I could finish up what I absolutely have to get done this year, and then could make a decision on what to do with it over the winter.
If, and it's a big if, the transmission works even to some extent after cleaning and putting in new oil then it's living on borrowed time IMO. You will have to baby it along in that scenario. I am more than a bit skeptical that it will work any better than it did before you drained the oil, if it works at all. If all that is failing is a clutch or clutches then running it until it fails completely is probably not going to involve any more parts replacement than you would be into if you pulled it right now. My opinion - YMMV. BTW to pull the transmission first the radiator & guard have to be removed, then the engine, converter, & transmission are removed as a unit and split apart after removal, so be prepared.
It should certainly be worth rebuilding. A good running 950 is still popular. You will probably get away with a rebearing reseal with some clutch discs.
I would just be using it for some light work, but problem that I've got is that the loader is out in a field about 12 miles from where the work I need done is, so I would have to road it. The loader hasn't had the easiest life before I got it, articulation joints are fairly worn and the bucket is wearing thin and going to need a rebuild in the next 600 hours as its starting to crack out in some of the repaired areas, also will need a new front window. Tires were replaced at the last dealer so they are at about 80 - 85%. Engine runs good but does have some blow-by and will burn a bit of oil if you are working it hard. If I could at least pull the transmission out then I think it would make things more feasible, but I don't have the right equipment to pull out that large of an assembly, so I would have to hire out all the work. If its got major problems it going to be a tough decision for sure. Probably looking at dumping 30k into a loader that will only be worth 40k when its all said and done.
Also, I am curious if you would have an idea of the book time or about how many hours it would take to just remove and install the transmission? I'm guessing that the rebuilding of the transmission would be hard to estimate as it would depend on if you just doing what needs to be fixed vs a total rebuild? Thanks
I’m out of the loop nowadays and have no access to the R&I times, but even then they are a lottery. Because the book says to snatch the transmission along with the engine and converter there is no procedure (and also no time) to remove it on its own, even if that were possible - and I have no idea whether it is or isn’t. Removing the power pack means the cab gets to stay on. Do it any other way and I suspect that the cab has to come off, so you’re as bad burned as scalded regarding the number of R&I man hours.
To update on the situation, we put some new filters in and refilled the transmission with oil. No luck this time. It can drive around on solid ground in first or low RPM second gear, but as soon as you touch a dirt pile or soft ground the transmission kicks out. So it looks like I'll have some decisions to make as I get priced out what the rebuilding cost will be next week. Thanks everyone for the help and advice.
You're welcome to the R&I instructions plus the D&A for the transmission if it's any help.