So this is what H-D recommends for the M8 transmissions and apparently you can put it in primarys as well.
Does anyone know anything about it?

 

I had it put in my 2018 Roadglide during the 1000 mile service. The Service Manager recommended it. It was $20 a quart.

 

Have you noticed any differences in the shifting?

 

I actually have noticed a difference. With whatever was in there originally, I had a hard time finding neutral at the stoplights. Now it's easier.

My bikes got 1700 miles on it now, so I'm sure it wasn't difficult to find neutral because it was brand new.

Putting gear oil in a manual transmission just makes sense to me.

 

I too just as of yesterday had my 1k service done on my 18 ultra. They put it in mine as well. Seems smoother than whatever came in it.
Before, I had a 17 softail and they always recommended BEL-RAY gear oil. I like this hd gear oil, as it's synthetic. At least that's what the bottle says. 19.95 a qt

 

Seriously...
The service manager recommended the most expensive gear lube he sells...what a suprise.

 

Funny how that works huh. Lol

 

You do understand that gear lube and engine oils are measured in different ways. There is not a lot of difference in the viscosity of the gear lube and 20/50 engine oil.

 

The difference is, motor oil is not specifically formulated to lubricate gears as the constant meshing of gear teeth quickly shear/breakdown the additive package resulting in a lower viscosity. I don't know anyone who would run motor oil in a car/truck differential.

Gear oil is formulated to lubricate gears.

IMO, Harley Davidson was seeing alot of owners are running gear oil in their transmissions/primarys, and they wanted in on some of that action. I've been running Redline 75/90 gear lube which is from what I've read slightly below the viscosity of a 20w50 motor oil. I was going to go with Redline's 75/140, but I'm going to give the HD 80/140 gear oil a try when I change the fluids next month.

 

I just changed oil in a friends bike, the trans. oil came out white maybe it was this **** don't know. I used Bell Ray in the trans.