Disappointed in Mobil 1 Gear Lube

[SteveD2]

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I would consider the yellow metal thing to be an internet myth.

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While this might be true, this is also NVG's reasoning for using GL-4 versus GL-5 fluids...the reason they require Syntorque and Synchromesh fluids...

steved

 

[Pablo]

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I would consider the yellow metal thing to be an internet myth.

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While this might be true, this is also NVG's reasoning for using GL-4 versus GL-5 fluids...the reason they require Syntorque and Synchromesh fluids...

steved

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It is more or less all mushed together - New Venture probably doesn't want old fashioned super high sulfur, high TAN fluids. Very reasonable. AND there is simply no need for the EP and FM's (or lack thereof) in a GL% diff. fluid.

(Fluids with potential to build/hold acids especially Cl- and -NO3 bearing fluids - ARE death to brass/bronze)

 

[wgtoys]

I'm also no fan of M1 gear lube. Royal Purple gear lube, on the other hand, is working very nicely in the several different rear differentials I've put it in.

 

[Jim 5]

For comparison's sake, here's a picture of the gear oil I drained from my BMW diff at 26k miles sitting beside some new Redline 75w-90 gear oil that replaced it in the diff.

I don't think it means anything, but it might give you some comfort that it is normal for a gear oil to change color in this type of environment.

 

[PT1]

FWIW...Mobil1 75w90 did not hold up very well in our lab tests for differential gear/bearing tests. It does not handle high pressure applications like heavy towing. The best we tested were:

#1 GM synthetic 75w90
#2 Amsoil 75w90 severe high pressure
#3 Valvoline synthetic 75w90
#4 Mobil1 75w90 synthetic
#5 Valvoline 75w90 dino (Mobil1 barely beat it)

 

[ant]

Did you test Neo or Redline 75w90, or did you compare the 75w90s to 75w140?

 

[TimVipond]

PT1, could you share which ASTM tests were run and the results of each test?

 

[PT1]

ASTM D5570, L-37, L-42. I'm not allowed to share any data.

 

[ant]

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ASTM D5570, L-37, L-42. I'm not allowed to share any data.

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But, you have already shared some of the data.

 

[TeeDub]

The issue here is mainly one of excessive viscosity at low temps. Most of the 75w-90, GL-5 rated gear lubes are formulated fairly thick in order to provide good protection in differential applications. This impacts their ability to provide good shifting in a transmission application at very low temps.

The API 90wt gear lube spec allows a lot of leeway in terms of viscosity. If you compare the GL-4 rated, Amsoil transmission/tranaxle oil to their 75w-90 Severe Gear for example, you'll see the Severe Gear is much thicker at all temps, but especially so at lower temps where shift quality is an issue.

Just to clarify:

NV4500 transmissions use the 75w-90, GL-4 rated Amsoil transmission fluid

NV5600 transmissions use the 5w-30, Amsoil MTF fluid, which does not contain extreme pressure additives, ie sulfur/phosphorus compounds.

TD