After reading Road Rage's posts on LE lubricants I decided I would like to try their gear oil. One of the things LE claims is a reduction in gear box temperature when using their fluids versus "other" brands. So I installed a temperature sensor on the back of the diff this weekend and recorded the differential temps today.

The "redline runs" noted in the chart are the runs I made to test injector duty cycle, described in another post. I was surprised how quickly the temperature increased with only a minute or two of faster driving.



I figure I'll do this for a few trips, change the oil, and do it again with the new fluid. Since I make the same trip every week I figure I'm a good candidate for repeatable test conditions. The only thing that will vary is the ambient temps so I'll make a note of that.

I'll continue to post temps charts as this test progresses and we'll see how it goes.

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Is this sensor actually immersed in oil, or just attached to the diff itself? If the former, how did you mount the sensor? I'm looking to do the same for my diff.

UL

 

Potentially GOOD STUFF coming from this thread.

 

[QUOTE]Originally posted by ultimate lurker
Is this sensor actually immersed in oil, or just attached to the diff itself?

 

Ah, Modifry, now I know what the 140 degF meant in the other thread - I thought you were referring to a Georgia Summer - which can seem like 140degrees, no doubt.

I am interested in the results, certainly, but temp reduction is not my main goal with this lube - it is more about shock loading protection, and wear over time. Heat contributes, certainly, but is not the main factor in my opinion. I know the temp reductions LE cites are seen in OTR rigs, which actually have sensors in the tranny sump to report back to the owner/operator in the cab.

Many of the big OTR tranny mfr's like Allison will warrant the tranny for a million miles (and require that the drain/fill blots be tamper-proofed), if the owner/operator or fleet director uses certain lubricants which have been showsn to be vis stable, excellent on the HT/HS tests, and reduce op-temps.

I would not expect LE to perform better than Mobil1 or Red Line in this test - if it does, then it really has an extraordinary additive package. Synoils have two advantages when to comes to heat:
1) They produce less heat intrinsically since they are less susceptible to self-friction heating - in other words, a PAO or ester has less self-inertia, so it produces less heat overcoming its own viscosity
2) Synoils have higher coefficient of thermal transfer - they "pull" heat off of metal better, and "release" it more effectively as well.

Also, LE607 is mono-vis. So its viscosity will not vary as much in the heating and cooling cycles as Red Line or Mobil1 will. And it will never shear.

Thanks for continuing to add to the pool of knowledge - I, and one would hope others here, will benefit. At the least, it will stimulate a rich dialog (it already has). There are plenty enough Internet "musings" around - we need people who can capture, interpret, and communicate what they know and are willing to share with others.

 

Data from 2 more runs. diff temp is obviously directly related to both speed and ambient temperature, which is not surprising.

I also noticed that immediately after speeding up the diff temp drops slightly, then increases a minute or two later. I assume that 's caused by the increased air flow cooling the diff, but then the increased load causes the temperature to rise.

 

[QUOTE]Originally posted by Road Rage

2) Synoils have higher coefficient of thermal transfer - they "pull" heat off of metal better, and "release" it more effectively as well.

 

Modifry, which diff. fluid was used for part 1 of your test? Can we expect the part 2 test results any time soon?

 

Redline synthetic was in the tranny for part 1. I have not posted any more run data because it all looks the same.

I just changed to the LE607 last week and will be making my first comparison run tomorrow. I only want to compare my drives from Atlanta to Charlotte to keep variables to a minimum.

One of the problems I ran into in Part 1 was that my digital thermometer only reads to 158

 

brilliant. please continue with an actual scientific anal-lysis