Motor oil in the gear box just seems "kissing your sister" wrong.

John

Don't know anything about GL5 but I always run gear oil in the gear box. But you will hear different opinions on that. One thing is for sure, there are almost as many different oil opinions as there are members.

 

I've read a lot about the "what oil to use in the tranny" debate. Many people state they use GL5 gear oils. It's well known that GL5 additives corrode brass. Do Harley transmissions have any yellow metals in them?

John

GL5 is corrosive to brass only at temperatures of 250F or higher.

If you can get your trans up to 250F, you've got more problems to worry about than "what oil to use".

It's hard enough getting motor oil to 250F! (In a motor with proper A/F mixture)


http://www.harley-davidsonforums.com/forums/oil-filters/29825-oil-info.html#post423570


If you're really that paranoid about it, use GL-5/MT-1 spec. It is not corrosive at any temperature.

 

Sorry. Post deleted. We're talking transmission here. I didn't read close enough.

 

Some GL5 lubes have additives to slow/decrease the effects on brass.

HDs have no brass in the trans, anyway.

 

GL-5/MT-1 is not corrosive at any temperature.

 

Good points, makes my decision to switch easier!
John

 

I run the Belray 80w gear oil in my trans. The local bike shop puts in the HD primarys also. It seems lighter than regular 80w car gear oil. He has no complaints from anybody. It says on the bottle for primarys also.

 

Is Mobil 1 Synthetic 75w90 gear oil a good choice in the transmission?

 

only in a 5 spd...they are rated at gl5 or better,the 6spd's are rated at a gl6 because of the mix of straight cut and helical cut gears from what i am being told:thumbsup