Not what you think.. It's time for mama's first oil change on her Nightster. Am I right in thinkin' the tranny oil & primary oil are the same? And most run gear oil....... 70W90....??

Thanks much

 

No answer??

 

I don't run gear oil in like some others I always use the Harley Sportster lube in the primary,Mobile one syn. in the engine.I have never had any issues.

 

Yes, the Primary & Tranny are shared, takes 1 quart (32oz.). 75w-90 Gear oil is correct. I run Mobil-1 75w-90 syn. Gear Oil. HD's Formula+ is an 80-85 weight non-syn Gear Oil. FYI - HD no longer recommends using Engine Oil in the Primary/Tranny.

 

cHarley - I keep seeing that "primary and tranny are shared". What exactly does that mean and have they always been that way and what happened?

(Not trying to highjack the thread)

I had an engine builder recommend Royal Purple to me years ago. Been using it in my metric and never had any issues in over 50K miles. I plan to use their products in my Sporty too, as soon as it's time.

 

In most motorcycles, especially metrics and even Victory's, they use a single common oil supply for the engine, primary and tranny. Harley BT's have 3 separate supplies, 3 different oils possible, for the engine, tranny and primary. Sportsters have a seperate oil supply for the engine and a secound supply for the tranny and primary.

The theory goes. that the engine, tranny and primary are different environments and that it's preferable to be able to use diffenent oils for the different internal environments.

Engine oil is specifically designed to deal with the byproducts of the combustion process. Gear oils don't need to deal with the combustion byproducts but instead are formulated to better deal with molecular sheering that occurs in the tranny with the meshing of the gears.

Basically, there is no such thing as a perfect, one size fits all oil. Those that run the same oil in the 3 different environments are compromising with "It works OK" vs "It works the best"

 

Great reply and you are so right when you said, "Those that run the same oil in the 3 different environments are compromising with "It works OK" vs "It works the best"."

 

Thanks for the very good explanation, cHarley. So by "shared" you are referring using a common substance in both separated areas. Very well. I thought I was missing something (I know, I surely am missing something.) because the metrics do share the same container space.

Sorry about hijacking part of your thread, Traveller. The one thing I would mention is that the experts say the worst synthetic is better than the best dinosour. Check out the Royal Purple. Hard to find though.

 

Thanks all for the info. That's what I was thinkin', but wanted to ask.

Sundog, no problem. Good info came from that little side track