Questions about Motul diff oil.

[oldmodman]

I just got a Wavetrak differential. And it specifies Motul 75/90 fully synthetic gear oil if you want to keep the lifetime warranty.

It additionally says to use absolutely NO friction modifiers.

Are either of our lubrication mavens familiar with that product. It's Motul 300 75/90 Fully Synthetic. Kinda pricy too? Maybe not at $19.00 a liter

 

[UnleashedBeast]

Curious as to why they are biased on Motul. There are other 75W-90 formulations on the market that could protect that differential. I understand why they do not want friction modifier. Last I read, the Wavetrak requires some friction to operate correctly.

I would not lose sleep at night using Amsoil Severe Gear 75W-90, since I have never read anything "unique" about Motul's formulations. Wonder what others on the forum have been using in their Wavetrak rear end builds?

Check out this tidbit of information. LINK

 

[oldmodman]

I wonder if each countries distributor is making their own decision? Or if Wavetrac is saying Motul because they are a Motul distributor.

Here is what Wavatrac's own website says. And they are located in Southern California at the factory where it is made.


"What gear oil should I use? [-]

Your new Wavetrac® differential is incredibly durable and will withstand the harshest environments...as long as suitable oil is used. Many customers ask what oil we recommend for use with the Wavetrac® differential. We feel the best answer is:

Use the "factory fill."

In other words, use the gear oil spec that your car manufacturer recommends for your car. The Wavetrac® is compatible with virtually all factory-installed gear oils used today. If you are racing your vehicle, and wish to upgrade the gear oil to improve performance or durability in racing conditions, choose the oil carefully: be aware that some gear oils have additives that are not recommended for use with your Wavetrac®.

Some have friction modifiers designed for limited slip differentials. These modifiers generally increase slipperiness and are intended to reduce clutch disc chatter in conventional clutch-type LSDs. Some gear oils such as Red Line Oil's Shockproof® type have microscopic solid particles in immersion in order to "cushion" transmission components, acting as an extreme pressure agent. The Wavetrac® and all helical gear differentials in general, operate using friction. The friction generated between its internal gears and its housing are what allow this type of differential to function.

Gear oil additives that drastically reduce friction will actually reduce the performance of gear differentials. The internals of the diff get too slick to generate adequate friction - reducing the differential's effectiveness - reducing its ability to drive both wheels.

In conclusion, when using a Wavetrac®:

Use factory spec oils for your car
Use Motul Synthetic high performance oils if you wish to upgrade the oil. Please consult Autotech Driveline for recommendations.
Avoid gear oils with limited slip additives.
Do NOT use RedLine, Shockproof® or similar gear oils.

Performance Gear Oils we recommend:
Requirement Oil
75W90 Motul Gear 300 (100118 1l)
75W140 Motul Gear Competition (101161 1l)
Motul Gear Oil is available from Wavetrac dealers



Please note that you will void the Wavetrac® Limited Lifetime Warranty if incorrect gear oil is used."

 

[UnleashedBeast]

So, use a premium or factory recommended lubricant and do not add additional friction modifier. This could be why some differential companies recommend cheaper gear oils that have no friction modifiers in them.

I do know that Amsoil Severe gear has extreme pressure modifiers in the formulation to assist with metal on metal crime.