so I have searched and search and read the plethora of Oil, Trans, and Primary threads asking what people use. I did notice there seems to be 2 distinctive sides regardless of the type/name brand products you use.

Those that use 1 oil product in all 3 and those that dont.

Is there a good/bad of using a single oil product in all three holes? I was always told that Oil in the tranny equals BAD.

 

I use a 20w/50 syn in the crank, 75w/140 heavy trans fluid in the tranny, and a dino oil in the primary.

 

Amsoil 20-50 in engine and primary.
Amsoil severe gear oil in the trans.

 

Bel Rey 20 W 50 - crank
B & M Trick Shift - clutch
Redline Shock - trans

 

Amsoil 20/50 in crankcase
Amsoil Severe Gear in tranny
HD Formula+ in primary

 

Here is the best approach I have found to the fluids.

M1 20w50 V-twin in the engine
HD Formula + in the primary
Redline Heavy Shock Proof in the transmission

You can get away with running synthetic 20w50 (engine oil) in the primary until you start making some serious torque. Once your above 105 ft. lbs of torque (think cams, heads or a 107 kit) you're going to need the dino oil to help the clutch plates.

Running engine oil in your transmission is not a good idea, especially when there are such good transmission oils available. Be good to your transmission and use some real gear oil in there.

 

red line oil: V-Twin Power Pack...everything you need in one box... look it up

 

Mobile 1 V-Twin in the engine and primary
Redline Heavy Shockproof in the transmission

 

1,000 mile check went with:

Motor: Amsoil 20w50 synthetic
Tranny: Spectra 75/140 Heavy Duty 6 Speed
Primary: Harley Formula +

 

Brad Penn 20w 50 , Val 75/90 Trans Dino oil 10w 40 Primary