just bought my wife a nice 02 883 9800mi. my question is the manual shows 10 /40 engine oil as best and says sport-trans fluid for primary. I ride a Street Glide and use same oil for all, what is best for this model any advice appreciated thanks

 

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You are not using the best oils for your SG! Read the manual for that.

There is more on HDF about oils than is healthy, so go do a little reading. You won't get any sensible answers if you do and you won't get any sensible answers with this question either I'm afraid. There are too many oils and even more quack ideas on what is 'best'.

There, I've said it!

 

GR, I should have clarified, I run Amsoil 20/50 in my SG engine and primary, redline in the tranny. was just asking if anyone was running similar method in an older sporty same engine and primary oil , I guess I will find out at the dealer i cant find the viscosity value for the tranny/ primary in the manual anywhere

 

ooops! manual calls for HD sport-trans fluid just wondered if it could be substituted with a 20/50 or something like that. Thanks

 

TD, this is a difficult subject, it really is! There are just so many ways of skinning this poor cat.

 

As far as HD branded oil, Sport Trans fluid is not made any more and has been replaced by the Formula+ fluid. There are a lot of guys who substitute 20/50 or M1 gear oil. Some gear oils are not safe because they contact yellow metals inside the chaincase and can corrode.

 

I went to the HD Dealer they told I could run 20/50 in both if I use the full synthetic oil.
I have been running for about a 1000 miles.
that's my 2 cent worth.