I've got a Komatsu PC50UU-1 that I'm just getting used to, new to me. I want to change the oil in the final drives before putting it to work but can't find what oil to use. I've got the PDF manual, I think all that's available for it, but there's no spec for the final drive oil. Anyone got any idea? It's a Hy Dash final drive. Also, it's got the rubber tracks, do the rollers or front idler require lube? I can't find any way to lube them. Thanks, Greg
10w will do just perfectly, there is plugs on all rollers, and idlers and carrier rollers use a hex. Should be level with the plug.
They appear to have 80W90 in them now. 10W would be a pretty drastic change? Thanks for the reply. Greg
All the gear drives on Komatsu machines I've worked on used 30Wt. engine oil. It probably changes for tropical or arctic climates.
Thanks, John. There are a number of things the manual does specify lube for, and I think they're all 30 wt engine oil. I'm just surprised a gear train would use that. Greg
use SAE 15W-40
I would imagine you're coming to the conclusion of 80W/90 that you say is in there now by a combination of the smell & the viscosity. There seems to be 2 schools of thought on final drive oil. Some manufacturers like Cat recommend a TDTO SAE 50 or 30 depending on ambient temperature, others like Hitachi recommend an EP 80W/90 oil. Don't get confused by the apparent viscosity difference - an SAE 50 oil is almost the same viscosity as an 80/90 EP gear oil. I've had good results using TDTO in excavator final drives even though the manufacturer in question didn't necessarily recommend it. If you choose either one oil type or the other you won't go far wrong. I've just had a word with a colleague who used to work for a Komatsu dealer - he says TDTO SAE50. Personally I wouldn't even consider using either 10W or 15W/40.
Gear oils are usually considered extreme pressure lubricants and are used where there are highly loaded spiral cut gears. Hypoid, amboid and worm wheels are examples where the extreme pressure lubes are used. Planetary final drives all use straight cut spur gears which are not loaded to the same degree and they spin much faster. The engine type oils are better at protecting the bearings. I had a Komatsu service rep tell me that at one time Komatsu wanted to be able to use the same oil in everything to simplify maintenance for the end users.
Cat was wanting to go down that road at one time but they eventually came to the conclusion that because of the differing lubrication demands of engines vs hydraulics vs power trains it was never going to happen.
My impression of Cat was that they started recommending different oils when they started selling their own line of oils.
Yep...all Cat is doing is trying to force everyone to buy there oil. In older machines that had a single or double gear reduction in the final drives being in a dozer, excavator or even a swing gear box i use gear oil. 80/90w In most machines made after mid-90's the finals and swing boxes went to tight spaced planetary systems and even in say 650h&j dozers and similar style finals they set up the gearing with little to no clearences not leaving room for a thicker viscosity. thinner oil is required as the thicker gear oil will cause excess friction and heat and wear components down faster. i use a 30w engine oil in most. the case and john deere backhoes 4x4 planetaries and your mini exc planetary is very small and tight...using a good hy-trans or trans/guard would be the recommened way to go. this is all my two cents...not necessarily a fact. but it has gotten me by just fine!
I was just reading through the oil specs for my pc50 mr -2 and I was surprised to see that they spec SAE30 for the final drives and Engine oil for the hydraulic system! The dealer that I bought the machine from did a complete fluids change before I took delivery. The hydraulic fluid that he put in is green. The stuff I usually buy is clear. I wasn't expecting to see engine oil as the spec for the hydraulic fluid. Is anybody running engine oil in their hydraulic systems? Any reason why this would be preferable over hydraulic fluid? I don't agree with the service manual for the 500hr final drive fluid top off and 1000 hr interval change. Should I listen to the manual for the fluid specs?
Engine oil in hydraulic system is an acceptable alternative from the performance point of view (but not if the system requires ashless zinc-free oil) if you are trying to reduce the variety of oils you have to keep. Engine oil however is more expensive than hydraulic oil. I just looked at this issue the other day when we went to place our order for the next 6 months of oil supplies with our oil company and we are paying about 35c a gallon more for engine oil than we pay for hydraulic oil, so why would we want to put engine oil in a hydraulic system..? Not so as far as I'm concerned. Every current Cat O&M Manual lists Cat oils alongside "commercial brand" oils for any given compartment and all are listed as acceptable for use. The thing I like about Cat O&M is that they give you an oil specification to work with - anything meeting the spec is acceptable, compared to a lot of OEM manuals that simply give a list of oil brands and types. Strange then that every off-highway truck I'm aware of recommends TO-4 or FDAO-spec oil in the differential and final drive housing.
I don't have enough equipment to have to worry about trying to consolidate the types of oils used. I'm already paying enough for hydraulic fluid. No need to upgrade that expense. As for the final drives, SAE 30 is a something that I would have to add to the collection of jugs. Is 75-90 gear oil too thick to be used? It's more expensive than 30 weight, but I use it in the volvo ec15. Would the volvo suffer if I switched to 30 weight? I was surprised to see the engine oil spec as I used to buy komatsu hydraulic fluid for the PC300 that I had. I assumed that they would have spec'd that for the mini excavators, too.
Maybe you didn't get my point. Hydraulic oil is cheaper than engine oil, at least it is from the sources where we buy it. So it doesn't make sense for us to use engine oil in hydraulic systems even if it is an approved alternative because it's more expensive. Like many people you appear to be confusing viscosity ranges. There is a range of viscosities for "engine-type" oils which also includes TO-4 powertrain oils. There is a completely different viscosity range for Gear Oils. A commercial brand SAE30 TDTO/TO-4 oil has a viscosity of around 96-100Cst @ 40 DegC. I took Conoco and Mobil data for these numbers. A commercial brand SAE50 TDTO/TO-4 oil has a viscosity of around 190-200Cst @ 40 DegC. I took Conoco and Mobil data for these numbers. A commercial brand 75W/90 GO/GL-5 oil has a viscosity of around 100 Cst @ 40 DegC. This data from Valvoline-branded oil. A commercial brand 80W/90 GO/GL-5 oil has a viscosity of around 140 Cst @ 40 DegC. This data from Mobil & Cat-branded oil. For my money on the basis of viscosity a 75W/90 Gear Oil would work fine in finals if that's what you already have. As you can see from the numbers above it's just about bang on the same viscosity at the sort of temperature a final drive would work at than an SAE30 TO-4 oil. The only caveat is that I have seen instances where the EP additives in GO/GL-5-spec oils have been known to attack the silicone rubber in the toric rings of typical metal face seals contained in final drives. I have no idea if this would happen in your case.
As long as I have worked on them, Komatsu has always specified 30 wt. engine oil for their final drives and swing reducers in the excavators. I have seen people use gear oils but have also seen those units develop a horrible smell when those oils were used. I don't recall anyone having a problem with seals but have had a Komatsu factory rep say that those oils weren't compatible with the rubber rings they used on the final drives. Those compartments will run a lot warmer with the heavier oil. I would think the machine might burn a little more fuel as well. As far as the hydraulic oil goes I think it is a lot more dependent on the ambient temperature than anything. I've been out on burn jobs in the far north where the hydraulic oil was more lighter fluid than oil. As for the amount of time between service for the finals I would say those are in line with what I've seen industry wide. In actuality I've seen plenty of final drives that have well over 5,000 hours with out changing the oils with no problems. I wouldn't recommend it though. Nige, the acronyms you are using come from the Cat branding and don't tell anyone what they actually are. I would suspect those oils have high pressure additives for the extreme pressures put on the gear teeth. If not, then Cat has something different done in the engineering so that they don't need those additives. I remember the arguments on the old D8 and D9 finals where the factory specified 50 wt and everyone was using 90 Wt. I've worked on Haulpac, Terex, Volvo and Moxy off highway trucks and they all used gear oils in the axles and final drives. On the other hand I was told a month ago that Cat has gotten out of the oil business in the United States. Apparently the local dealer will sell what they have in stock and go back to the local suppliers.
Not entirely true sir ......... TDTO (Transmission/Drive Train Oil) is a Cat acronym and that's what is on the label of the pail/barrel/whatever it comes in if you buy a Cat-branded oil. Only Cat-branded oil can be labelled TDTO and in that you are 100% correct. However, although TO-4 is a "Caterpillar specification" in as much as it was Caterpillar that first came up with it, it is also an oil industry-wide spec for commercially-supplied power train oil. Therefore anyone wanting to use a suitable commercial oil in a Caterpillar drive train would ask for an oil of whatever brand he wanted "meeting Cat TO-4" spec. That would be the case whether the oil came from a major such as Shell, Mobil, Conoco, or from Joe Blow's Oil & Bait shack. So in summary, only Cat-branded oil is labelled as TDTO. However Cat TDTO also meets commerical TO-4 specification (it would be a bit silly if it didn't, not so?). Commercial brand oils meeting TO-4 specification are regarded as being identical as regards specification in all respects to Cat TDTO with the one exception - they can't be branded as TDTO. P.S. Our Cat fleet uses either Mobil or Conoco (that's where I pulled the info above from) lubricants, not Cat-branded product. So if Cat were using different additives in their TDTO oils wouldn't you think they'd be denying us warranty amongst other things because we were using an "oil that didn't meet the Cat spec"..? Well I can tell you they don't. The branded lubricants we use are in all respects identical to the Cat oil, they are just NOT labelled TDTO.
Nige, I understood your point that hydraulic fluid is cheaper. I guess my yankee accent comes across when I type and confuses things . I'm still learning when it comes to oil and lubricants. I'm a fast learner, but sometimes you have to explain to me for a long time.
Refer to my earlier comments regarding the difference between SAE engine oil viscosity definition (which also includes powertrain oils) and Gear Oil viscosity definition. At operating temperature an SAE50 TO-4 powertrain oil is actually a higher viscosity (18.0 Cst vs 14.5 Cst) than an 80W/90 EP Gear Oil. It would require somewhat of a 90/140 gear oil to have approximately the same viscosity as an SAE50 TO-4 at operating temperature.
Bit like - Q: What can you tell a woman with 2 black eyes..? A: Nothing. You've already told her twice ............
For the last time....... she FELL