So 75w90 is whats in the mt82, no wonder it shifts notchy. What would happen if you used something much thinner? Syncromesh, synthetic atf, or synthetic motor oil?????
Unleashed no comment to my question about viscosity in the mt82?
Sorry, I missed this last time.
75W-90 GL-4 manual transmission gear oil was the original specification for the Getrag MT-82. The notchy feeling is caused more by a cheap base stock lubricant than the viscosity itself.
We used Amsoil MTG in a Grabber blue 5.0 yesterday, and the shifts are much improved.
Another car, we used Amsoil Synchromesh. That car also shifted well, but I believe the Synchromesh car had more gear roll over noise.
The TSB Ford fluid has a very low viscosity, about on par with ATF. A wide range of viscosity has been used in the Getrag so far. IMO, the best yet has either been true synthetic manual transmission fluids like MTL or MTG, or true synthetic Synchromesh type fluids.
Are you saying it's not ok to use Mobil 1 75w90 gear oil in the MT-82? I know on the second page you said Amsoil MTG is rated at 14.8* on the cst @ 100*C scale. Mobil 1 is rated at 15.2* so it's a tad bit thicker. What other differences are there? I haven't read of anyone using Mobil 1 in the MT-82, I'm just curious.
I'm not saying it's not worth a try, but beware. Mobil 1 is notorious for using group III base stocks in their formulations, yet calling them "fully" synthetic.
They use a group III+ base stock that is proprietary to them, and it's called VISOM.
A natural evolution of the formulation
The Mobil 1 formulation strategy has always been based on selecting the best components available. We now have the very high quality Group III+ base stock, ‘Visom’ exclusively available to ExxonMobil. As we developed the Mobil 1 ESP technology we found that combining Visom with PAO could deliver a formulation of equivalent performance to an all PAO formulation.
Competitive advantage
Visom is the only non-PAO stock that can deliver the required performance to formulate a 0W grade oil that meets European OEM engine oil specifications. Visom is not available to our competition.
To support Mobil 1 growth
Global PAO capacity is limited. As we quickly approach this limit, new base stocks must be explored to ensure we can support the continued growth of the Mobil 1 family of products.
To ensure continuity of supply
As we saw with the 2005 hurricane, the more flexibility we have in our formulations, the better placed we are to withstand disruption to our supply. We can balance PAO and Visom supply fluctuations to ensure we can always deliver the final product to our customers.
To maintain market relevant pricing
As PAO supply has tightened globally, raw material costs have increased substantially. In the future, an exclusively PAO formulation may be priced out of the market or result in significant margin erosion.
To prepare for next generation basestocks (GTL)
Commencing 2010, the next generation of base stocks derived from Natural Gas (Gas To Liquids) will enter the market. These high quality basestocks will arrive in substantial quantities and will probably be used in the majority of competitive premium formulations. Visom is viewed as a precursor of GTL, and hence it’s use now in our flagship formulations eases our transition to a GTL world, and helps us understand how to maintain flagship performance using these high quality non-PAO basestocks.
Careful how you read their stock holder release babble above. This is Mobil 1's way to say..."Hey, we found a way to make more money, and our consumers will never know the difference." This document was more than likely meant for internal release only, but found it's way onto the internet at bobistheoilguy.com/forums.
For years many have asked what base stock Mobil 1 was using, but they would not say a word. Tight lips! You can't hide the truth forever. So those of you who support Mobil 1 thinking you are getting what you are paying for. Think again.
