Case 580L backhoe

[sdan27]

This is the latest UOA from our Case 580L backhoe. Has a Cummins 4-cylinder engine. The engine tag is missing so I'm not real sure if its a 3 or 4 liter engine. It is naturally aspirated. Using Service Pro 15w-40 engine oil with a Fleetguard LF9028 venturi combo oil filter. The oil was last changed back in March of 2011 and should probably be able to go for another couple years.

Unit hrs 3870, 4414
Oil hrs 412, 544

Iron 29, 25
Chrm 3, 2
Alum 2, 1
Copp 2, 2
Lead 3, 4
Sili 7, 4
Sodi 3, 4
Moly 264, 66
Anti 1, 0
Boro 15, 21
Magn 928, 795
Calc 1618, 1329
Phos 1062, 993
Zinc 1323, 1188

Fuel 2.1%, Soot .1%, .3%
H2O Visc 13.3, 14.4
TBN 4.64, 5.54
Oxid 9, 14
Nitr 14, 11

 

[Barkleymut]

What is the oil capacity?

 

[MaxPF]

The engine will be a 3.9L 4BTA rated for 90HP. Oil capacity is probably 10 quarts plus 1 in the filter.

 

[dnewton3]

Jiminy Cricket ...
Yet another boring (excellent) Service Pro UOA from you?

Great wear, low contamination, plenty of TBN. Easily another 2 years if the current rates are indiciative of future performance. Outstanding!

Think of the monetary waste avoided by doing a few UOAs rather than blind, calendar/hour based OCIs. Applied over your fleet, there is a huge savings you're experiencing.

 

[MaxPF]

Assuming you can trust the UOA. Viscosity and TBN increasing with use??? TBN increasing as mag and calcium compounds are depleted??? Seems pretty questionable. Moly EP compounds have taken a severe hit, while ZP compounds are depleted to low levels for an engine with flat tappets. Soot is .3%, which is a fair bit of abrasive running through the engine.

The oil has been in the crankcase for 2 years and 544 hours. 3 gallons of conventional oil and a filter is under 50 bucks. I'd say $2 per month is an excellent value out of the oil change, and a pittance compared to the cost of fuel used (fuel cost to maintenance cost ratio). The cost of the oil analyses would have already paid for new oil and filter. Dump it and put fresh oil in the crankcase.

This shouldn't be a contest to see how ridiculously far you can push an oil, especially when your only gauge are some questionable numbers on a questionable oil analysis. You've gotten more than your moneys worth out of the oil. All you are doing now is running a filthy lapping fluid with poor AW protection through your engine, and spending the money on routine OA's means you aren't actually saving ANY money. A replacement long block will be 8 grand. A replacement backhoe will be a lot more. The math does not favor extended OCI's...

 

[dnewton3]

To really understand the TBN and vis, you'd have to know the R&R of the testing equipment and personnel, as well as the normal variation of exposure. I take it with a grain of salt; the TBN is certianly high enough to not warrant concern. It's not low enough to worry about TAN.

The shift in vis is not an automatic condemtation for the fluid. A bit of oxidation is not only expected, but desirable, as it adds to the physical barrier between parts, as documented in SAE study 2007-01-4166. The hotter the oil gets, the better film formation that protects against wear. Too much (heavy sludging) is obviously bad, but we're nowhere near that problem.

 

[sdan27]

I should have specified that the on the first, earlier oil analysis, the oil was drained at that time. On the latest analysis, I merely took a sample without draining.

 

[dnewton3]

Well that helps explain the TBN shift; it's two separate sump loads. Mystery solved!
Makes OCI extension that much more viable!


If you wish, I will edit your OP with update of the OCI info for clarity; it's up to you.

 

[MaxPF]

Originally Posted By: dnewton3
Well that helps explain the TBN shift; it's two separate sump loads. Mystery solved!
Makes OCI extension that much more viable!


Not sure how it makes OCI extension more viable. The initial assumption was that this oil had been run for 544 hours, whereas instead we find out it has only been run for 132 hours. Seems to me the oil is becoming contaminated much faster than initially thought...

 

[dnewton3]

No - you're still not on the right track.

Sample one had 412 hours total on oil. OIl was drained.
Sample two had 544 hours total on oil; not as an increment of 132 from sample one. Oil was samples but not dumped.

Look at the unit hours and the oil hours.


Excellent UOA and worthy of much extension.

 

[MaxPF]

You're right - I misunderstood the hours.

Dump it and replace it. You're not saving anything by continuing to run dirty oil.

 

[dnewton3]

What?????? Dump oil that is in fantastic shape? There is a lot of life left in that load. Why dump it? Could possibly go 2x!

He would be "saving" the cost of the sump load, for the cost of a UOA. And, he's gaining knowledge that is the antithesis of the "short OCI" mantra, letting facts and data dictate an OCI rather than a calendar or hour-meter.


What criteria are you basing your "dirty oil" statement on?

 

[MaxPF]

If this was a truck, 544 hours would be about 25,000-32,000 miles. The oil is dirty.

I know extended OCI's is the fad on this site, but I recall seeing Cummins test data on extended OCI's. Two engines, both N-14s. They ran both on the dyno, recorded the HP numbers, then ran both engines under simulated load for 300,000 equivalent miles and 250,000 equivalent miles, respectively. The 300k mile engine got 12k mile OCI's, while the 250k mile engine got 25k mile OCI's. After the conclusion of the simulated load run, the engine with 12K mile OCI's only lost 3% HP, while the engine with 25k mile OCI's was down over 10%. I'm sure the UOA on the 25k mile OCI looked great, though....

For the money wasted on a UOA he could have had a fresh sump load of oil. Instead, he will run it another 2 years and 500+ hours and accelerate the wear on the engine. Personally, I don't care since it isn't my equipment. Hopefully, if he ever sells it in the future he will be honest with the buyer about maintenance.

 

[Doug Hillary]

Hi,
sdan27- I agree with Mr Newton - the oil is indeed suitable for further use