D6C Final Drive Sea

[Nige]

No ISO Cleanliness Code on the analysis so there no idea of how many large (>5μm) particles are present. The microscopic analysis generally only measures the presence of particles smaller than 5μm.
39ppm of iron wouldn't necessarily worry me; 38ppm of Silicon indicatess it's got a load of dirt in it, especially at only 34 hours of operation. Either it wsasn't cleaned too well when it was torn down or you've got dirt getting in somewhere.

 

[Nige]

Just to elaborate a bit further, up to 50ppm of Silicon would be a value within the "normal" range for an oil sample taken at 1000 operating hours. Up to 65ppm "monitor compartment", and over 66ppm "Action Required"
Your silicon value is 76% of the normal limit at only 3.4% of the hours. That's what would worry me most on your sample analysis.

 

[Metalman 55]

Just to elaborate a bit further, up to 50ppm of Silicon would be a value within the "normal" range for an oil sample taken at 1000 operating hours. Up to 65ppm "monitor compartment", and over 66ppm "Action Required"
Your silicon value is 76% of the normal limit at only 3.4% of the hours. That's what would worry me most on your sample analysis.

Perhaps we should do an oil change in the finals straight up & then contiue the monitoring process moving forward?

 

[Nige]

TBH what I would suggest is get the machine well up to operating temperature & drain the oil. Fiill the final drive with a mixture of 10W oil & diesel and let it run with the track in the air on no load for 10 minutes. Drain & refill with new SAE50 oil and then see how it goes after 100 hours.

 

[John C.]

You should contact the dealer who processed the samples and ask their advice. They are the ones you are going to sit down with if something goes wrong. The dirt was probably in the new oil or the dispenser when you got it. Most of the big companies out here require new oil to run through a filter buggy to fill the compartments. I've taken samples on new oil and seen what you have there. Most of us little people wouldn't bat an eye at those readings.

 

[Nige]

I'm not sure I follow you here John. I don't think the dealer rebuilt the final drive..?

I will say one thing though. The interpretation of the analysis results never mentioned anything like "contamination levels consistent with a rebuilt component" or similar, especially as it was obviously taken early when the oil only had 34smu on it. "No problems presently associated with this sample. Continue sampling at the normal interval" ought to be challenged. It sounds as though whoever did the interpretation completely missed the hours on the oil as a factor.

 

[Metalman 55]

Here is the results of another oil sampling taken a few weeks back, being the LH final drive with an additional 150 hrs on the D6C. We sampled both sides, but for some reason the RH sample got lost & hence no results.

I am a novice at reading the results, but see that the "Fe" which is iron is a lot higher...….any problem with that?

Also, the machine is sitting at the yard now & we are ready to take another sample. Is it important for the machine to be active for a hr or so with the oil warm to get things mixed, or can viable sample be taken with the machine sitting, as we need to re-do the RH side now? The last sampling was taken when the machine was working with the oil warm.

 

[Nige]

You won't get meaningful results unless the machine has been worked for a while and the oil is at normal operating temperature IMHO. Also as you say the last samples were taken with the machine working and the oil warm, so if you did it sitting & cold you would not necessarily be comparing apples with apples.

I'd be more worried about the amount of silicon (dirt) than I would about the iron. It very close to the reportable level right now. Is there a chance dirt is getting into the compartment through the seals or is there a possibility that the cases could have had contamination left in them when the FD was rebuilt..? The level at which iron becomes reportable is around 150ppm, but with more hours on the oil.

Also the ISO from the previous sample in May at 23/21 meant that there were a fair number of larger particles (in the 5-15 micron size range) kicking about in the final drive at that time. It's a shame the ISO test wasn't run on the August sample. I'd suggest you get it done on the ones you plan to take now. Oil analysis result interpretation is all about trends.

 

[Metalman 55]

I am not aware of any dirt getting in. Can dirt migrate in if there are not leaks, which is the case here.....all dry.

I was not there when things went back together, but the person who did the rebuild was quite particular about cleanliness, so I trust all was clean.

I could change the oil & start over I suppose & then monitor the trend again.

 

[Nige]

I’d see how the results of the sample you’re planning to take now come back before making the call to change the oil again. You should definitely ask them to do an ISO cleanliness test on it imho.

What did the magnetic plugs look like..?

Generally dirt can only get in if there is oil leaking out through a seal. As John C pointed out previously there is also the possibility that there is dirt in the new oil. If that was the case though, the silicon number ought to stay relatively constant.

 

[DMiller]

Dirt could have infiltrated the sampling equipment and contaminated the samples previous. Been down that road.

 

[Metalman 55]

We didn't pull the magnetic plugs in Aug.

I am sorry, but don't know what the ISO test is comprised of? We can ask if necessary.

 

[Nige]

The ISO test was done on the first sample from May, but not the 2nd sample. I’d simply ask for them to do an ISO test on the samples you pull now, it’s obvious they can perform the test because they have done it before. You can see the ISO result (23/21) on the centre of the bottom line for the May sample.

 

[Nige]

Here's a bit of an explanation of how the ISO Cleanliness Code works. if there's anything you don't understand, shout out.
http://www.apacheoilcompany.com/company-forms/ISO-Cleanliness-code.pdf

 

[John C.]

That's all well and good but the article is talking about hydraulic systems and not final drives in thirty plus year old dozers. Yes it is good to keep that stuff clean. In reality, most final drives in old equipment like this haven't had an oil change in many years and probably thousands of hours of use. I've sampled hundreds if not thousands of final drives in the last forty years and nearly all come out high iron. Does it indicate an imminent failure. No!. We just changed the oil and sent the machine back to work or down the road to the next owner. I've not had a come back. On the flip side I have had good oil samples and found broken teeth in the drain when the oil was changed. The samples were so unreliable that I've convinced most of my customers that it isn't worth the money or the risk of contamination to take final drive samples on oval track dozers. I check the oil level and if something strikes me as odd, such as water in the oil, level over full or way low, or a leak somewhere around the ham case or sprocket, I'll take a sample as a provable fact to show my customer.

If the sample results bother you, then change the oil and take it again in a couple of hundred hours. Just don't lose sleep over one sample in the mid to high range for a final drive.

 

[Metalman 55]

We did another final drive oil sample & will ask them to conduct the ISO test this time. Hope they don't loose a sample this time like they did last time!

 

[Kelly]

Makes sence to me!

Kelly

 

[Kelly]

We have had a weeping final drive seals on both sides for some time, so decided to replace them one at a time. Took the housing apart to inspect things inside & so far all bearings/races look good. The #5S6531 Holder has wear from where the track pivots at the back & the large brass pivot bearing is shot too. Have ordered both the new Holder & the Support #5M6636, as they were reasonable priced. I have never been able to get grease in that back pivot since owning it. If there are any words of wisdom to send along, I would appreciate it. I have a young mechanic helping me with the work as a fill in job, so it will take a while to complete. We are both feeling our way, but think we will get there ok. He does a lot of work on the newer Cat equipment. Once we get this side done, we will likely tackle the other side if the cost does not get too far out of hand. Stay tuned........

 

[Metalman 55]

Just got the D6C final drive samples back via email this morning, these samples were taken with the oil warm after the machine had been working a few hrs. I see our sampler neglected to write the meter reading on the RH one (489 hrs) same as the left one. I notice the iron is up quite a bit, but perhaps it is ok as everything is showing green?

 

[DMiller]

Start getting reports into the Yellow warning would be of concern, believe that to be over 500ppm. Engines can have up around 150ppm and still be normal(ring to sleeve wear) where gear train will show abrasive wear as well.