What about under light acceleration?
What about at say 50mph in neutral?Your explanation of whine sounds like some ring and pinon wear has occurred and a thicker oil might help mask the symptom but not a cure. The Amsoil 75w 110 should be more than adequate but you state no change occurred. The 75w140 oils are worth a try to quiet the whine but keep with the synthetics. The higher hot viscosity oil usually are used where high ambient temperatures are present of use where high gear oil temperatures are expected like racing. More detail: Your research probably has come up with the following but I post it for information anyway: As far as the gear lube the viscosity ratings are independent of the brew. The ratings are done to determine the viscosity at specific temperatures. The low number is a cold value (called winter) measured at 40 C, the high number is a hot value measured at 100 C. The higher the viscosity numbers the thicker the oil. Mineral oils have unequal molecule size (by nature) while the synthetic oils have equal size molecules (by design). The synthetic brews last longer as a result of uniform molecular design and less additives (viscosity index improver) to control the temperature viscosity change of the oil. Mineral oils are subject to greater shear degradation (especially with gear teeth design in hypoid differentials) and do not last as long and they require more viscosity improver additives to control the temperature viscosity changes. Thus mineral oils have more viscosity improver additives (less pure oil in the can) than synthetic oils. Mineral oils with a greater difference in the viscosity rating (5W -30 compared to 10W-30 as example) have more viscosity improver in them to design the oil to give the design hot viscosity rating. The wider the viscosity spread the more viscosity improver additives in the can. Synthetic oils by design need less to no viscosity improver to achieve the desired hot temperature viscosity rating thus they are more stable. Here is more detail to research [ http://www.doolittleoil.com/faq/viscosity-sae-iso-or-agma ] I
ZUL8TR in Orlando,FL |
