What is the rated viscosity of HD Formula+?
HD doesn't give a viscosity rating or range for use in their trannys but to me it would seem like Formula+ is a bit too thin for the application for a gear lube.

 

Quote:

Harley Davidson Formula+
Application: recommended for heavy-duty service in manual transmissions where the manufacturer normally recommends either engine oils or GL-1 lubricants.
Specific Gravity: 0.857
Pounds per Gallon: 7.14
Viscosity, ASTM D 445,
cSt at 40°C: 168.04
cSt at 100°C: 20.10
Viscosity Index, ASTM D 2270: 139
Brookfield Viscosity, ASTM D 2983,
cP at -26°C - 28,800
cP at -40°C - n/m
Pour Point, ASTM D 97, °F (°C): -60 (-51)
Flash Point, ASTM D 92, °F (°C): 507 (264)

Harley Davidson FORMULA+ Trans and Primary Chaincase VOA


Petroleum based.

Ca 169
P 230
B 210
S - some
Zn - essentially none
No other elemental additives.

Vis. within SAE 50 range.

Listed as a GL-1, does test out as a GL-3.

Harley owners may be better served by using a lube that meets GL-4 requirements and has more P and Zn, and a basestock resistant to shear.

 

Just installed Spectro 75W150 platinum 6 speed GL5 trans lube in my 2012 SG.
I did have Bel Ray prior 85W150 and I noticed that the Spectro is a tad bit louder during shifts.
But I like the idea of a synthetic gear lube and I think the lower viscosity of the Spectro should flow into the bearings better.
Does anybody think that 75W150 is too thick for proper lubraction of my SG tranny?
I see that Baker recommends Spectro for their 6 speeds so I guess it should be good for my stock tranny.

 

Just installed Spectro 75W150 platinum 6 speed GL5 trans lube in my 2012 SG.
I did have Bel Ray prior 85W150 and I noticed that the Spectro is a tad bit louder during shifts.
But I like the idea of a synthetic gear lube and I think the lower viscosity of the Spectro should flow into the bearings better.
Does anybody think that 75W150 is too thick for proper lubraction of my SG tranny?
http://www.spectro-oils.com/?p=273