Gearbox oil SAE number? - The Harley-Davidson Riders Club Great Britain

**Tony Cross** · #1 07-09-2009, 02:37 PM

Can anyone tell me what the SAE rating is for H-D gearbox oil?

**banquo** · #2 07-09-2009, 05:12 PM

Well, it makes a change to have an oil thread that's about the transmission instead of the engine Tony, but the answers will be just as obscure....

I believe Harley recommend Syn-3 for all three cavities, and are subjected to much abuse for doing so. It's a 20W-50 synthetic.
However, Amsoil are now doing the same, recommending their MCV engine oil for all three holes...
"In the Evolution 1340, Big Twins 1450, and V-Rods, AMSOIL recommends MCV 20W-50 motorcycle oil in all 3 holes (engine, transmission, and primary chain case). AMSOIL recommends SVG as an alternative oil for the transmission, and SVO as an option for older transmissions. New seals are recommended where excessive leaking exists."
Make of that what you will.
MCV is a 20W-50, and their alternative oils are also Multi-Grade, varying from a 75W-110 to a 75W-140.

Others seem to offer an 80W90... possibly EP.

Take a look at a typical thread here.

**Tony Cross** · #3 07-09-2009, 06:17 PM

Thanks Jake. I am thinking of trying 75W90 to see if the 5th gear is quieter.

**Urrell** · #4 07-09-2009, 07:15 PM

Quote:

Originally Posted by Tony Cross

Thanks Jake. I am thinking of trying 75W90 to see if the 5th gear is quieter.

Tony 75w-90 gear oil is not a lot thicker if any at all than 20w-50 engine oil.

**Tony Cross** · #5 07-09-2009, 07:42 PM

Quote:

Originally Posted by Urrell

Tony 75w-90 gear oil is not a lot thicker if any at all than 20w-50 engine oil.

The MoCo transmission oil seems as thin as water. I might consider 80W-90 but am willing to experiment / consider knowledge offered.

**banquo** · #6 07-09-2009, 07:53 PM

A lot recommend Redline Heavy Shockproof; but some don't....

It's an oil thread, innit....

Personally, I use the Formula+, simply because I got sent a load of it free by mistake from Guernsey (but that wasn't why they went bust I hope...). It works for me... but on 5-speed.

**the_monster** · #7 07-09-2009, 10:05 PM

I think the noise of the 5th gear has more to do with the way the gears are cut than the oil - I'll be surprised if the oil makes much difference apart from the fact that a thicker oil will take longer to get up to operating temperature

**Urrell** · #8 07-09-2009, 10:27 PM

Sawdust

Comfort yourself with the fact that straight cut gears are stronger than helical and don't have to cope with sideways thrust.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode