RS2000, I read the article you posted by the Amsoil rep. It could be that everything he said is true; however I am always skeptical when one is related to the company they are saying good things about. I quoted part of the article here.

"Additionally, the temperature of 50

 

[QUOTE]Originally posted by nsx555
...I just read Modifry's thread on his differential temp.

 

Hey RR.... where are you now that we need ya?

 

Since about all I have at this point is questions, I'm certainly no expert. There seem to be some rather obvious questions that need to be answered.

1) Temperature is not likely to be constant at all locations in the diff. There will be areas where the local temp is much higher than the fluid temp. I would think that the way the lubricant deals with hot-spots is as important as the average temp of the lube. We've all seen demos where one lubricant is drawn to heat while another moves away from hot-spots. What is appropriate for rear-end lube?

2) How hot does the oil in our diffs actually get? Surely someone has installed a temp gauge to see? I'd like to see representative temperatures achieved in city driving, highway driving, track and autocross. I'd like to see some graphs rather than just a few spot measurements (which is all I've seen so far). The question has already been raised as to whether or not the 607 stays cooler because it lubricates better or because it doesn't carry the heat away from the hot-spots as well, and if there has been any hard evidence on this point I've managed to miss it. How hot do the lubs get? What is the true cause of the temp differences.

3) RR has put a lot of work into this, a fact I think we all appreciate greatly. He's also pointed out that this isn't rocket-science, which may well be the only thing he's been wrong about. Rockets are just stable-tables, chemicals, and materials-science, but lubrication is REALLY complex. AMSOIL has also put a lot of work into understanding the lubrication requirements of various applications, as has LE. It is hard to overlook the fact that AMSOIL actually makes a specific recommendation for our cars, and that their recommendation is consistent with a Honda TSB that has been dismissed because it mentioned a proposed spec that never came to pass. That is not a valid reason to reject the TSB, IMHO. LE makes NO recommendation for our diffs, and we've seen one Honda dealer REFUSE to put the 607 in a customers car. IF the claim from AMSOIL is true, and it takes many minutes for the 607 to work it's way through the diff, then that Honda dealer seems to have done the customer a favor. Is AMSOIL lying to us? Is RR absolutely sure that his advice is the best advice (better than that from AMSOIL and Honda)? It may be, but how can we/I be sure? (NOTE to RR: This is as bad as reading audio rags, but I don't have the equipment or knowledge to test lubricants the same way I can test audio gear. As a result, I just don't know who to trust.)

4) We have several members who have 75,000 to 100,000 miles on their cars, and have had NO problems. Do any of them do track days or autocross their cars? What lub has allowed their diff to survive for so long? How many of these high-mileage cars have been using whatever their Honda dealer decided to use?

I almost ordered a quart of LE607 last Sunday, but all the conflicting information has me on hold. Screw all this theory, I want to know what autocrossers have found to give good reliability from their rear-ends. If it works for them, it will work for me, theory not withstanding.

Has anyone added a pump and oil cooler to their diff?

As interesting as this all is, it's very frustrating.

Thanks for the effort RR. Sorry to be such a bonehead.

RED

 

So far, from what I have read, there is no TSB except for in Canada, which could have been done just because it is not easy to find a 90W oil there. I wonder what Europe and Japan do. It seems fishy to me that Amsoil rep and the Honda dealer above would say that the 90W that Honda recommends in the manual is no good.

 

That's not what I understood them to say. I thought they said was that the 607 was inappropriate, and gave some justifications for that position. Whether the justifications are valid is as yet (for me) an unknown. I didn't see where they said that the recommendation in the manual was wrong, and saying that an industrial grade lubricant made for low speed gears is a bad idea doesn't seem suspect to me. Seems like a damn good question. How many club racers are using LE607 in their S2000's?

I'm really starting to think that I should have bought the Super 7 rather than the S2000. The 7 might be old, but at least they're not so exotic that you can't use common lubricants. The S2000 is turning out to be a major disappointment in several areas.

RED

 

[QUOTE]Originally posted by RED MX5
2) How hot does the oil in our diffs actually get?

 

Let's see - a Honda dealer won't put it in one car, and an Amsoil dealer makes a bunch of statements that are off the mark or addressed in what i have posted in this thread, and you are ready to balk at using LE-607? Amazing. I didn't just pick this product out of the air.

I will not get into a pizzing match with any retailer; I will state a number of facts that will speak for themselves. I have no financial affiliation with LE, other than arranging a GB as a service from one Board member to others - I clearly stated that I made no money, and never intended to, since I wanted to remain impartial. As we shall see, having a financial interest can lead to commentary that is at best inaccurate, at worst disingenuous.

Many people were looking for a gear oil of 90w which could stand up to severe service - and that's what i went looking for.

1) Amsoil 75w90 will never thicken up to match the vis of LE-607 (actually, it is wrong to state that they thicken at all, since the oils will thin, they just will thin less than would be predicted for their bases, 75w or 90w, respectively. Amsoil's vis at 100degC is 15.7 cSt; LE-607's is 20.96 cSt. So Mr. Amsoil's claim that there is equivalence at higher temps is not correct.

I believe there is also implication that Amsoil 75w90 will be an ISO 220 oil at higher temps. The ISO spec measures kinematic viscosity. Well, the spec for ISO grading is at 40degC, and Amsoil is 113 cSt at that temp, LE is 235. The minima/maxima for ISO 220 is 198-242, which LE meets at the higher end of the range. Amsoil does not come close; it is more a high range ISO 100 or a low ISO 150.

2) LE-607 is a variable purpose gear oil. It exceeds API GL-5 specs, and is recommended for differentials, hypoid gears, and many industrial gear applications. Calling it an "industrial lubricant" is a red herring, as it implies (as evidenced by the doubting Thomas's here) that it is an improper gear oil for use in our cars. That was the purpose of the Amsoil guy's comment, and it worked for the technically ignorant (I mean that in the literal sense of the word).
Here is the MSDS/spec sheet:
http://www.le-inc.com/Literature/MSDS/0607.pdf

3) LE-607's flash point is 410degF. Amsoil's Series 2000 75w90 is 388degF. This means that LE will have less of a tendency to vaporize.

4) The temperature advantage clearly goes to Amsoil, but this was never an issue of great importance, and we were looking for performance under severe service at higher temps as being more important to the longevity of the differential.

LE-607's pour point is -11degF. Amsoil's is -51degF. I never once hid this, but Amsoil's sales representative claims by implication that LE-607 will take a long time to flow readily. In fact, it will not, assuming you use it within the range of temperatures for which it was designed. Most 90w's have a pour point well above 0degF - well, LE-607 is not like most 90w's. I took LE-607 down to 0degF and it flowed well enough to satisfy me. But certainly no one was having the wool pulled over his eyes about the low-temp issue - not by me, that is for sure. In fact, I cited that for people like xviper who live in Canada and other cold places, the choice was to either swap out the diff oil during the winter, or go with another product.

5) Amsoil uses conventional ingredients in its gear oil - zinc, phos, and EP additives. So does LE-607. But LE-607 also has a proprietary additive, Almasol, which is an EP component which has as high a film strength as moly, yet will not glom up or interfere with any tolerances. It also is effective at lower temps than the usual EP additives, and reduces friction at all times, as well as wear under boundary lubrication situations. That is why it can lower temps even in gears running at fairly low RPM compared to our cars.
You can read more about it here:

http://www.le-inc.com/Literature/Misc.%20L...SOL%20Flyer.pdf

6) I already posted the 'load bearing" capabilities of LE-607 vs others in the first post in this thread.

7) The Amsoil salesman (he does not claim to be anything other than that) completely ignores the fact that Honda has recommended 90w oil, nearly all of which will not flow as readily as LE-607 in cold climates, yet there it is as the factory fill in every S2000 ever made. How do you reconcile that, Mr. Amsoil sales person? Has Honda completely missed the boat?

In closing, let me point out that I have never said anything bad about Amsoil's 75w90, and indeed, I use it in the rear diff of my Subaru, which specs 75w90. In the center diff, I use Amsoil 80w90, because that is what Subaru calls for in that application.

Honda calls for 90w gear oil for its differential, and my research and findings were posted for those with an interest in using the factory recommended lubricant. Amsoil 75w90 is not now and never will be equivalent to the viscosity and load bearing capability of LE-607. While"Service Bulletins" may at one time have been sent out to dealers to deal with the challenges a 90w gear oil faces at low temps, it proves nothing. I think it is significant that Honda's stated recomendation, both in the Owner's Manual and in the Helm Service manual, is 90w. A 75w/80w90 lube may be acceptable, but there is a difference between acceptable and optimal. If Honda had found there to be no performance difference between its 90w recommendation and any other viscosity ranges, it has had plenty of time to change that recommendation. It hasn't - I submit it hasn't for a reason, and I further submit the data in this thread makes a compelling case why Honda has not changed its recommendation.

I will not lose a moment's sleep worrying whether my multi-grade 75w90 has sheared down because a mono-grade won't. Nor will I lose a moment's sleep worrying whether a diffrential failure within the warranty period will be covered by Honda if they find a non-recommended product in use.

 

RR,

Being one of the technically incompetent, I don't know whether to thank you for your answers or chide you for the attitude.

Thanks for the effort, but the attitude is not appreciated.

RED

 

You want attitude, read The Absolute Sound.