Hey guys doin a 10,000mi on my 09 street bob and a 1,000 mi on the wifes nightster and i got the oil for the eng and the trans but i have no clue as to what to fill the primary with freind told my 90 weight but that dont sound right also heard ATF was the way to go any thoughts

 

Syn3 from Harley-Davidson will be fine in the primary. That's what Harley-Davidson dealers put in the primary when doing 10k service.

 

Most will agree a good 10w40 oil will work , then some use a synthetic oil, i.e. redline, M1 20w50 or syn3.

 

You're not transferring hydraulic force, so don't use a hydraulic fluid (ATF). Use a fluid that's formulated to be a lubricant first & foremost.

 

Actually some transfer cases on 4 wheel drive units use an ATF. Most of those are chain driven and automatic trannies have clutch packs and clutch bands that some to work on ATF. Personnally I've used syn 3 in both of my dynas with accumulated miles of 50k and no problems.

 

90 wt?? NO WAY!! i use 10-40 amsoil in mine

 

Try Redline MTL. It is a 70w80 GL4 gear oil with no moly and just slightly thicker than ATF.

 

Hey fellas thanks alot for the help appreciate it a hole bunch

 

10,000 miles on an 09 already, CRAP I need to get out and ride more!

 

no its 1,000 on the 09 10,000 on the 07 that would be pretty hard core though