Don't think I've seen it anywhere yet, but my owners manual says to replace the primary and trans with Formula+Transmission and Primary Chaincase lubricant...What weight is this stuff? Is it synthetic? I'm putting Mobile 1 V-Twin 20-50 in the crank.

 

I'd like to know the answer to your question also. And more generally, what are the specifications for the engine, primary, and transmission oils. I've never seen them, even in H-D service manuals. Just use H-D oils is all I've read.

BTW - metric bikes show oil specifications, not brand names.

 

The engine calls for diesel ratings only and 20w50 for a wide temperature range. It should say in theowners manual. Synthetic or Dino is your call...not really going to make a big difference.

The transmission is 80w90 GL5 and the old HD official bottle use to say that too. I am not for sure if the newer bottles still say that or not. Anything else other than Gear oil really should not be there.

The primary does not give specifications and never has to my knowledge. The only two specifications are to stay away from friction modifiers and energy conservation. The clutch is incompatible with those too items and can cause slippage. I have been told from a pretty reliable source that the old stuff was 10w40 motor oil.

 

To my knowledge, the newer bottles are vague at best as to what they contain. So your reply is as close to specs as I've ever read. Thanks.

 

In the trans you want to use a GL5 75w90 or greater gear oil that you can get for $2-25/qt depending on how **** you are. The primary you can use anything from ATF to GL4 manual trans lube as long as there is no moly in it to coat the clutch plates. (me I use Redline MTL in my primary and Shockproof Heavy Gear oil in the transbecause I'll never burn it out)

You won't find much technical mumbo jumbo from Harley regarding their lubricants because they are "specially formulated" by Hugo Chavez........and he hates Americans...well most Americans except Cindy Sheethand...but Cindy don't ride no Hog.

 

From what I understand, Formula+ is a semi-synthetic engine oil, about 10w30 with a bit a EP added, a ripoff at $6.50/qt. and IMO unsuitable for tranny use. Use 10w30 or heavier multi-viscosity fossil engine oil (cheaper may be better in this case), ATF, or MTL in the primary and a 75w90 (preferably synthetic) gear oil for the tranny. Despite HD's rantings about diesel ratings, any 20w50 engine oil will work, although I wouldn't use a fossil oil in the engine. There are simply too many good reasons to use synthetic in the engine of your $20k bike than to yield to a small price difference that amounts to small change every oil change.

 

Here is what I gleaned from the bazillion page oil thread...

Synthetic choices:

Group V
Redline oils 20w50 for engine, MTL for primary, Shockproof heavy gear oil for trans

Group IV
Amsoil MCV 20w50 Engine & Primary, 75w90 Severe gear for trans.

Mobil1Vtwin 20w50 for engine & primary, 75w90 gear oil for trans.

 

That pretty much sums it up.......

 

The crux of the oil discussion is...


Engine: Any 15w50 or 20w50 synthetic motor oil (from among the usual suspects: M1, Amsoil, Royal Purple, Redline, ad nauseam). Does not need to be labeled as motorcycle-specific.

Tranny: Any 75w??? or 85w??? synthetic gear oil (from among the usual suspects). Non-synthetic gear oil is best second choice.

Primary: Almost anything except vegetable oil, including engine oil with zero or low moly content, ATF, and MTL. Vegetable oil might work, but you try it first and let us know how it works.


Select from above on the basis of cost and availability. One oil might make your hardware last 200k miles instead of 195, but determining which is impossible.

 

when 80W90 GL-4 is recommanded ,....you can't replace it for GL-5 just like that , because the newer additives could be agressive for oil-seal-rings and brass-alloy's !!!

10W40 SL / CF ( halve synth ) in the primairy.

20W50 SL / CF for engine ( crank-case )

Brand : VALVOLINE.