Anyone tired 90-115w gear oils on diff?
03-07-2005, 10:14 AM
#11
Registered User
Originally Posted by Squeezer,Mar 7 2005, 09:58 AM
there have been diff failures from people even after switching to LE 607.
If one drives the car like a jackass something on it will eventually give. The one thing that tends to give the quickest on the S2000 just happens to be the diff because people like to hear tires squeal for some reason.
03-07-2005, 05:14 PM
#12
Registered User
A little gear oil 101:
1) Gear oil that is way thick causes heat buildup, in part from its own inertia. That is, the sliding of the molecules one over the other, producing heat. All things being equal, a 140 weight will produce more heat from this effect than a 90w. Synoils are usually better at this than minoils, but since the RPM in a diff are much lowert than in an engine, it is not nearly as big a deal
2) Honda recommends SAE 90w, GL-5. LE 607 is exactly that.
3) Too thick an oil also affects the cooling of the diff. Consider that in anything but a race car, the diff fluid is not pumped, but rather relies on 2 cooling mechanisms:
a) "Splash" lubrication, from the lubricant being churned by the gears
b) "Tack" lubrication, where the oil's properties cause it to be attracted to metal, and stay on it even after the gear has moved out of the fluid compartment in the diff - this has various names, but the point is the same.
4) Synoils tend to absorb heat and exchange it into the air better than minoils, all things being equal. This does not make them necessarily a better gear lube, however.
5) Very viscous oils do provide better protection from shock loading - great for drag racing, or for hauling heavy loads, but neither should be the deciding factor in determining the best overall gear lube for a street car.
I like LE607, but also have LE 9921 available, and would have no problem using something like Mobil1 if I lived in a very cold region. Valvoline also makes a fine syn gear lube. Thing is, all the ones I have seen have been 75w90's, and they just do not have the spec of a 90w when things get hot. I am not saying do not use them, but just pointing out even though it says 75w90 on the bottle, that does not mean a multi-vis gear lube will have the same protection @100degC as a quality 90w. It will not.
LE 607 is rated to a pour point of -11degF, which is awesome for a straight weight minoil. They must have some excellent pour point depressants in there - most 90w's are rated 20 degrees higher! Still, I would not use it in very cold climates. My car never sees temps below about 55degF.
1) Gear oil that is way thick causes heat buildup, in part from its own inertia. That is, the sliding of the molecules one over the other, producing heat. All things being equal, a 140 weight will produce more heat from this effect than a 90w. Synoils are usually better at this than minoils, but since the RPM in a diff are much lowert than in an engine, it is not nearly as big a deal
2) Honda recommends SAE 90w, GL-5. LE 607 is exactly that.
3) Too thick an oil also affects the cooling of the diff. Consider that in anything but a race car, the diff fluid is not pumped, but rather relies on 2 cooling mechanisms:
a) "Splash" lubrication, from the lubricant being churned by the gears
b) "Tack" lubrication, where the oil's properties cause it to be attracted to metal, and stay on it even after the gear has moved out of the fluid compartment in the diff - this has various names, but the point is the same.
4) Synoils tend to absorb heat and exchange it into the air better than minoils, all things being equal. This does not make them necessarily a better gear lube, however.
5) Very viscous oils do provide better protection from shock loading - great for drag racing, or for hauling heavy loads, but neither should be the deciding factor in determining the best overall gear lube for a street car.
I like LE607, but also have LE 9921 available, and would have no problem using something like Mobil1 if I lived in a very cold region. Valvoline also makes a fine syn gear lube. Thing is, all the ones I have seen have been 75w90's, and they just do not have the spec of a 90w when things get hot. I am not saying do not use them, but just pointing out even though it says 75w90 on the bottle, that does not mean a multi-vis gear lube will have the same protection @100degC as a quality 90w. It will not.
LE 607 is rated to a pour point of -11degF, which is awesome for a straight weight minoil. They must have some excellent pour point depressants in there - most 90w's are rated 20 degrees higher! Still, I would not use it in very cold climates. My car never sees temps below about 55degF.
03-08-2005, 07:43 AM
#13
I did an "experiment" with Redline Shockproof. Here is that thread:
https://www.s2ki.com/forums/index.php?showtopic=141409
Although Shockproof will protect the diff, it is not long lived nor is it advisable to use it as a daily driven street car unless you are willing to warm the fluid up thoroughly each time and change it out in short intervals.
https://www.s2ki.com/forums/index.php?showtopic=141409
Although Shockproof will protect the diff, it is not long lived nor is it advisable to use it as a daily driven street car unless you are willing to warm the fluid up thoroughly each time and change it out in short intervals.
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