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What Primary Oil is your Choice
Seasoned HDF Member
Joined: Apr 2010
Posts: 33,714
Likes: 3,723
From: Connecticut.
@rocket23 True, True. I can't think of even one time I didn't get the oil I paid for. 
Tourer
Joined: Apr 2021
Posts: 273
Likes: 86
From: S.Texas
Mobil1 10w-40. Jaso MC oil. In my 16 FXDB primary’.After bike warms up, I can pull in clutch for 5-6 seconds before shifting in 1st and only feel shifter move down-no noise what so ever, no clunk, click, same going running through the rest of the gears. Not any noiser ( comp/chain/tensioner) than the 20-50 that was in there. I was told this by an ( older than me guy-and I’m almost 70). Said he’s tried everything out there ( and he works at a bike shop that sells almost every brand /weight MC oil there is. With that -I have some I-Ride 5w-40 Jaso) Guzzi oil I will try next.
3rd Gear
Joined: Feb 2022
Posts: 7
Likes: 3
From: South Africa
Hi All
Some useful information out of the service manual, hope it helps.
========
Harley-Davidson Dyna Glide Twin Cam 88
model from 1999-on.
Table 3 ENGINE OIL SPECIFICATIONS
Ambient operating
Type HD rating Viscosity temperature
HD Multi-grade HD360 SAE 10W/40 Below 40° F
HD Multi-grade HD360 SAE 20W/50 Above 40° F
HD Regular heavy HD360 SAE 50 Above 60° F
HD Extra heavy HD360 SAE 60 Above 80° F
Table 4 ENGINE AND PRIMARY DRIVE/TRANSMISSION OIL CAPACITIES
Oil tank refill capacity
With oil filter change 2.5 U.S. qts. (2.4 L)
After engine rebuild 2.9 U.S. qts. (2.7 L)
Primary chaincase 26 U.S. oz. (768 mL)
Transmission
Oil change 20-24 U.S. oz. (591-709 mL)
Rebuild (dry) 24 U.S. oz. (709 mL)
Table 5 RECOMMENDED LUBRICANTS AND FLUIDS
Brake fluid DOT 5 silicone
Front fork oil HD Type E or an equivalent
Fuel 91 pump octane or higher leaded or unleaded
Transmission HD Transmission Lubricant or an equivalent
Primary chaincase HD Primary Chaincase Lubricant or an equivalent
Cautions:
Do not add engine oil. Add only the
recommended primary chaincase lubricant
listed.
Do not add engine oil. Add only the
recommended transmission oil listed
Some useful information out of the service manual, hope it helps.
========
Harley-Davidson Dyna Glide Twin Cam 88
model from 1999-on.
Table 3 ENGINE OIL SPECIFICATIONS
Ambient operating
Type HD rating Viscosity temperature
HD Multi-grade HD360 SAE 10W/40 Below 40° F
HD Multi-grade HD360 SAE 20W/50 Above 40° F
HD Regular heavy HD360 SAE 50 Above 60° F
HD Extra heavy HD360 SAE 60 Above 80° F
Table 4 ENGINE AND PRIMARY DRIVE/TRANSMISSION OIL CAPACITIES
Oil tank refill capacity
With oil filter change 2.5 U.S. qts. (2.4 L)
After engine rebuild 2.9 U.S. qts. (2.7 L)
Primary chaincase 26 U.S. oz. (768 mL)
Transmission
Oil change 20-24 U.S. oz. (591-709 mL)
Rebuild (dry) 24 U.S. oz. (709 mL)
Table 5 RECOMMENDED LUBRICANTS AND FLUIDS
Brake fluid DOT 5 silicone
Front fork oil HD Type E or an equivalent
Fuel 91 pump octane or higher leaded or unleaded
Transmission HD Transmission Lubricant or an equivalent
Primary chaincase HD Primary Chaincase Lubricant or an equivalent
Cautions:
Do not add engine oil. Add only the
recommended primary chaincase lubricant
listed.
Do not add engine oil. Add only the
recommended transmission oil listed
Tourer
Joined: Sep 2008
Posts: 285
Likes: 1
From: Wisconsin
My bike went on the dyno the other day and was told the clutch slipped so some modifications were made. I am the running the darkhorse man-o-war compensator. It was quite for 50 miles. Then the dreaded chain slap noise (new chain, bearings and clutch spring) Tried amsoil and it was bad. Then tried syn 3 it was better. Now I'm using Schaeffers primary oil with my stock clutch spring back in. There is no slip and 90% quieter!!! $11.00 a bottle.
Road Warrior
Joined: Oct 2007
Posts: 1,696
Likes: 3,477
From: Wake Forest, NC
I've owned the 2001 Road King for 14 years and use Formula Plus in the primary. Always shifts smooth, runs quiet and easy to find neutral. I bought the 2014 Ultra about 10 months ago and the engine/trans/primary seem to run much hotter. So I used Syn3 in the trans and primary when I changed the oil. (cause synthetic gotta be better, right?) Clunky shifts and difficult to find neutral. I'll probably try something else next time. Maybe something with higher viscosity? Most of my riding is above 60 degrees. Sportster seems to be OK with Syn3 in trans/primary but it doesn't get ridden too much. I always use Mobil 1 engine oil.
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