So I was planning on changing the dirty engline oil out for winterization...but I was curious to know if i need to change the primary and transmission oil as well? My thoughts were that since those oils aren't exposed to combustion that they wouldn't have those nasty corrosives accumulating in the oil. Any advice would be appreciated. Thanks guys!

 

There are a lot of write ups on this very subject.
It all depends on how many miles you've put on during the riding season.

 

This ^^^, pretty much sums it up.

Its only oil, and a couple of quarts at that. Furthermore, its got to be changed at some point anyway so if you've got miles on it, its worth even less to you.

When I'm not sure about decisions like this, I think it over while I'm changing the oil.

You are correct, however, the need to change primary and transmission oils is less compelling than it is with motor oil.

 

Tranny 'n primary don't have the need to change the oil as much, there's no combustion happening in there like there is with engine oil, no carbon buildup, thus no acids are forming as with engine oil.

However, it's cheap, takes just a couple-a-minutes, and if you enjoy bonding with your bike in the garage with a couple of beers in one hand and a wrench in the other hand...go for it! No harm done.

 

I'm with the majority; I change all fluids at the same time.
By doing this it helps me keep tract of the schedule and it doesn't cost that much or hurt anything.

That being said according to my owners manual;
Engine oil- every 5000 miles
Primary- every 10,000 miles
Transmission- every 20,000 miles

 

If I have more than 3000 miles on the oil before storing for the winter then I change it if not I leave it alone.

 

Purchase some Carharts and ride it.✌

 

I change my transmission and primary fluids every second oil change.