Mobile 1 synthetic 75w-90.

 

I've heard that the sulfur in gear oils can form sulfuric acid and attack stator windings. As a result, I stick to the Formula +.

 

Last year I ran the Mobil 1 75-90 gear oil in the primary. This year I threw in Lucas 75-90 Gear oil.

 

Amsoil 20w50 in the motor, Mobile 1 synthetic 75w-90 in the tranny.....'07 1200C... 26000 trouble free miles.

 

I decided to ask Amsoil why they recommend motor oil for the Primary-Transmission, as you can see they think there is a good chance that in 06 the Sportsters have the Primary separate and the motor-Transmission are together.
Below is my Question.



I have a 06 1200 Sportster. I have been using Amsoil 20-50 motorcycle oil for the last 3 years. Sportsters have the Transmission and Primary together. Some guys say to use Synthetic 75-90 gear oil and some say not to because it has a Transmission in with the Primary. I have been putting your Motorcycle 20-50 oil in my Primary. I have had no problems but I want to do the right thing. so what do you say I should put in my combination Primary-Transmission? and why? Your answer will be put up on some web sites... Thank you. Gary.

-----Original Message-----
From: Swaggert, Kurt <kswaggert@amsoil.com>

Sent: Wed, 6 May 2009 5:08 pm
Subject: RE: Technical Service Contact



Thank you for giving AMSOIL the opportunity to answer your email.



In response to your question; Using the motor oil in the transmission and primary is fine and I believe that in the 06 Sportsters, the "primary and transmission are separate", but the "transmission and the engine sump are together" but, I may be mistaken. The motor oil may be used in this application because it has been designed to be wet-clutch compatible. I have enclosed two(2) links one for the data sheet on our 20w-50 Motorcycle oil. The other is a link to our Motorcycle White Paper study.
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Well, he did say he may be mistaken. I cant believe that a Amsoil rep didn't know more about Sportsters. Kind of makes me Question there advice.