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Modifry: I love it - you are hard core, in a no-nonsense way. Keep up the good work. And based on the Amsoil assault on LE607 in UTH, you better get your results before the FTC removes LE607 from the market (like ephedra).
I finally got around to plotting my first run on the LE607 and added it to the previous chart.
No significant difference in differential temps, though I think it runs a tad hotter than the Redline 75W-90 that was used in the first 3 runs. I does appear to be slower to change temperature than the Redline, but that may be due to lower thermal conductivity (?) and because I'm measuring the diff, not the oil itself.
Modifry: That is what I expected. The self-generation of heat by a 90w due to its own molecules rolling over one another accounts for a fair amount of heat in itself. But the point is, even if RL ran 20deg cooler, it is the protection at higher temps and loads where the LE-607 should excel. Most diff failures from heat occur catastrophically when the diff is damaged (as in racing) or the drain plug loosens or is left off by a nitwit. Few diffs wear out from excessive heat unless the oil level drops, or the fluid is very poorly made.
Diff wear occurs when the boundary lubrication protection of the EP additives fails (assuming the diff is set up properly and not misaligned). Red Lien is a good choice because its base stocks are heat stable, and it has goodly amounts of standard EP additives. LE-607 goes one step further by having higher oil thickness at higher temps than any 75w or 80w90, and in its secret weapon - Almasol, which has the EP strength of moly, without any downsides.
I just got my UOA for the Redline diff fluid and Mobil 1 engine oil. I used LE, I think they go through Polaris. On the engine oil they said "no abnormal findings", on the diff they claimed ignorance - said I have to supply them the lube mfr, type & equipment info, which I did but apparrently they lost it.
This is with 5k on the engine oil and 21k on the diff, car had 111k at the time.
Not that I have a clue what this is telling me. Any enlightenment?
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Lead looks a bit high on the engine, no? What oil have you been using alla long, Modifry?
BTW, McMaster-Carr has a J-type IR thermocouple for about $185 that would eliminate the mechanical coupling to the diff, but since you sourced an el cheapo (sensible) thermometer, that might be overkill, but it is a thought. The IT thermocouple needs a dark target, that that could be done with black paint.
^ Fairly easy break-in, factory fill till 5k, then M1 10W-30 every 5k after.
I've not connected the "el cheapo" yet, but have played with it at home and it seems to work well. Nice sized display characters a really tiny thermocouple bead, can't be more than .05" in diameter. The lead wire is a little stiff though, may need to insert a piece of more flexible cable in the middle when I hook it to the diff.
The IR sensor sounds interesting, but I'm a cheap bastitch.
You say lead looks high on the engine oil, I have no idea. Does it matter that I had a valve job with new valves 11k ago? (nothing else done at the time)
Any suggestions on where I can get some info on making sense of these numbers? I'm willing to read and learn, but don't need to be an expert, that's what you're here for.
Go to bobistheoilguy.com, join, and read in the Used Oil Analysis forum. Look for cars and oils similar to yours, with similar OCI's (oil change intervals). There are some good analysts there, Terry Dyson is a tribologist. Molakule is also very knowledgeable, Buster, patman, etc.
For your miles and with the valve job, 11 may be OK, but i would do some comparative reading. The valves would show elevated iron, perhaps, but not lead. It may be that at this stage in your engine's life, you need a 10w40 (or 5w40) in the bearings. Also, Mobil1 tends to formulate at the low end of the API vis ranges, and can end up closer to a high 20w than a 30w after some use in a high revving engine from oil shear, and my thinking is that your car needs higher vis in the bearings.
You can also post your B;ackstone report and ask for other's opinions. I would suggest following the protocol to ensure you get a response from the "old pros". The protocol is the order of car, lube, miles, etc.
Thought I'd bring this back to life.
Today I installed my temp recording device on my diff. It's the one that Modifry linked earlier (in the thread I started about the cooling fins). It reads in *C. I attached it by contact cement to the "valley" between two fins (much like Modifry did) but I located mine on the left side edge, forward of the drain plug. I also packed the probe with a bit of automotive putty.
I did not do any recordings in the detail that Modifry did but here are my initial observations:
Using Mobil 1 gear oil and driving in the city for about 30 minutes with a couple of stops. Speeds not exceeding 55 mph. The temp started out at about 16*C (in my garage) and never went beyond 51*C (120*F). It's a bright sunny day, ambient temps about 22*C.
One really neat thing I noticed was that UNLIKE engine coolant and oil, as soon as the car stopped for any length of time, the temps started to decline. It seems that only while the gears are spinning around that heat is being generated. Of course, this should be logical as there is no other source of heat in the diff.
I don't plan on doing any detailed recordings as I'm sure Modify has that covered. I like the idea of gathering some "normalized" information on the diff temps so that I can use this for future reference. This will tell me if anything is amiss and when and when not to over-exert the diff - like in a clutch dump or repeated hard acceleration when the temps are abnormally high.
04-13-2004, 06:22 PM
