KDXrider045,
Do a search on oil and I'm sure that you'll find as many opinions as you will oil choices.
Here's the skinny (or at least my take) on gearbox oil.
Modern automotive oils (SJ) contain friction modifiers and other additives to help auto engines achieve better fuel mileage. While these modifiers don’t present a problem for the gearbox, they are problematic for wet clutches. They are simply too slippery for our use. Here are your choices…
1) Buy motorcycle specific oils;
2) Buy automotive oil that does not say, “energy conserving”. This would apply to some 10w-40 oils and most (if not all) 20w-50 multi-weight oils;
3) Buy gear oil;
4) Use automotive transmission (Type F is the most common cited).
They only reason not to use motorcycle specific oils is the high cost. If you change fluids frequently you will spend a considerable amount of money on gearbox oil. Any of the above will perform well provided that you change oil before it has lost its ability to lubricate.
What do I use? It doesn’t matter – like I said there are as many opinions on this subject as there are oil choices. You can use all of the above safely within limits.
Regarding filters, I highly recommend No-Toil. The product is 100% biodegradable. The filters can be safely washed in your kitchen sink with the supplied solvent/cleaner.
Once again, there are many opinions out there, but petroleum based oils require harsh chemicals to clean the filter and leave you with a dilemma regarding the disposal of the solvents. Moreover, you handle enough harmful chemicals just owning/maintaining a motorcycle (brake cleaner, oil, carb cleaner, brake fluid, fuel, cable lube)…wouldn’t be nice to remove one from the list.