Hello, we have recently acquired a used 12,000 hour D8T with recent trans and TC rebuild history. Machine had been sitting still for 2 years in tropical environment and we expected some rain may have entered compartments. Trans oil looked clean, but we changed oil and filters as a precaution. The machine has now worked about 4 hours, pushing beautifully and not over heating engine or trans. About 4 hours in a warning light came on and read-out says blocked transmission filter. Pulled the filters out, ( TC and trans) the trans filter had let go; ruptured along the join inside. The oil is very dark in filters and when we drained some of it. Pulled suction screen, all it has is fibre which appears to be from the filter where it let go, but no foreign material. Haven't had a chance to get an oil sample yet, but plan to change the oils/ filters again ( using recommended Cat 30W for our climate). Also plan to add magnets as none are fitted. Any suggestions are welcome. thanks Michael.
Could you see on the failed filter what the Part Number was..? An oil sample would be a good idea. You say you are using SAE30 oil. I hope it meets Cat TO-4 specification.... Rather than changing the oil again I'd just change the filter and see how it goes. If it had a recently rebuilt transmission & converter then it it's highly likely the system was full of debris from the rebuild and whatever happened prior to that (did the trans fail maybe?) Edit: What is the Serial Number prefix of the machine..? I thought it was strange when you said there were no magnets in the screen and every version of the D8T I could find has a sleeve with five magnets on it installed inside the Power Train suction screen.
Hello Nige ( or is that Ronnie?) The filters we fitted were Trans and TC: 1328876, one for each canister. Prefix for this machine is J8B. The oil we use is Cat TDTO SAE30 from the dealer. We are now about to fit the same part number for trans and part number 1RO778 for torque convertor. Either combination is optional. Trans was rebuilt due to slipping in 1st gear and machine had done about 1000 hours since the rebuild when we received the tractor; as mentioned we changed trans oil before we started working it due to concern of possible water contamination, age etc. Re the magnet in screen, it appears they were standard later in this series. I have now ordered a screen wirth magnets to fit to this tractor with the fresh oil. We considered using the old oil again and changing the filters a few times to clean it up, but I couldn't bring myself to use the dirty stuff again. So we will add clean oil in the morning, new filters, clean the suction screen and go again. This time we have drained the oil from 3 ports, including the TC housing, which didn't get done last time and hopefully we start with a very clean system. I don't know if there is any more oil in the TC but I don't think we can get it out if there is. I really appreciate your help. thanks.
Ok, 132-8876 is a High Efficiency or "cleanout" filter. They are for use after a component changeout for somewhere in the region of 50 hours or until the filter plugs whichever comes first. They are designed to plug in actual fact, and if they don't there's generally something wrong. 1R-0778 is Advanced Efficiency which means it won't clean out quite so well. TBH with new oil I would be very tempted to continue using the 132-8876 because even "new" oil isn't clean by the definition I use. Even if it takes a few filter changes before the filter quits plugging it will be worth it in the long run. At that point the 132-8876 can be used as a "service" element and changed every 500 hours or whatever the book recommends. That way your oil will stay clean. Did the oil smell burned when you drianed it..? It might be worth thinking about doing a transmission pressure check just to make sure you don't still have something somewhere out of specification, wehther it's in the pump, control valve, or the powershift itself. The type of transmission used on the T-series tractors doesn't like contamination of any sort, so it behoves you to get the system clean and also make sure it's in top order hydraulically IMHO. One thing I would recommend is to pull apart the bypass valves on both the transmission and TC filter housings and ensure that a) the spools are not stuck and b) that they have the correct springs in them. It seems weird to me looking at the Parts Manual that 132-8876 can be used in both the transmission and TC filter housings because the springs for the filter bypass spools are different Part Numbers. To me that suggests that 132-8876 is the preferred element for the transmission and 1R-0778 ditto for the TC. If your J8B machine is lower than S/N 4500 then it won't have a magnetic screen which seems ludicrous to me. Definitely a good idea to fit one.
Not sure exactly what different analysis processes are used in the lab where you send your samples but you should request that they perform an analysis to determine the ISO Cleanliness Code of the oil, that's if they don't do it as part of the standard analysis package, and post the results back here.
Very useful information, thank you Nige. There was no smell from the old oil. Have now changed trans oil and TC filters both with the 132-8876 high efficiency filters, and the dozer is pushing like a mad thing, better than before, spinning the tracks if you let it. Will get a few more hours up and change out the filters again and see how everything looks. We will have the tests you suggested done when our plant mechanic is close by again. We seem to have found another couple of issues with the dozer though, hopefully not serious. Engine occasionally gets a slight miss in the mid engine rev range, blows a good lot of blue smoke, then clears up again and runs smoothly. Just seems to happen intermittently when working hard. ( has new fuel filters about 10 hours ago and recently has valve clearances reset. Could be just a product of being idle for 2 years, I'm not sure. The other thing which seems abnormal is when pushing a full blade (SU) under full power, the blade cannot be raised unless the operator backs off the power a bit, then it immediately responds. Ill ask the question regarding the oil samples when we get them done and let you know. I appreciate the support.
I think putting the 132-8876 in the TC filter is not advisable, and here's why. The bypass spool spring in the TC filter is nowhere near as strong as the one in the transmission filter housing and is designed for use with the 1R filter. Because the 132-8876 is a very fine filter it's likely to plug more easily and when the bypass spool opens the the oil in the TC side of the system will be unfiltered while in bypass mode. Without checking I'm not sure if there is a plugged filter warning on that filter. If there is its not so bad but if there isn't then you have no idea your filter is bypassing.
Update......... There appears (and I say that advisedly) to be 2 plugged filter switches. They are listed in all the manuals as being for the PTO (***?) rather than the Power Train. We call things like this a Cat Design Feature - it's designed to ***k you up........ If I were you I would remove both those switches and physically operate them while checking that their respective warning lights come on in the cab to make sure that they are working correctly. If they are and one of them is on the TC filter housing then I'd be more comfortable using the 132-8876 in that location instead of the 1R-0778.
Just a quick update... new transmission oil has gone very black in only about 6 hours... "clean but black". getting this colour so quickly, the general consensus is leaking rear engine oil seal. Oil analysis to confirm is underway. looks like we might be pulling the transmission out... $ouch !
Heheheh.... PTO= Power Train Oil? I wouldn't put it past CAT (RDHVVF)
I hope you mean pulling the the torque converter to replace the rear crankshaft seal not the transmission ......... otherwise you'll be in for a shock ......
Correct, my mistake.. we will call in an expert, but is this a big job.. should we look at anything else that might need attention while we are in this far?
If as per your OP the TC has been recently rebuilt then it shouldn't need any attention but unless you're 100% sure of that it might be worth taking a quick peek in there. All it will cost you is a couple of gaskets and bit of labour. Not sure if there's anything else you could be looking at if only the converter is out of the machine.
Cheers mate, keep you posted.