Used syn 3 on all three changes and I also put on a newer outer primary gasket with a harley gasket.But the syn 3 just seems to seep more than normal. I feel I should drain the tranny and crank case again and use something else .Any recommendations what people are using these days?

 

There have been many stories of synthetic oil seeping out of an EVO then switching to dino oil and the seeps going away.

 

I wouldn't recommend using any synthetic oils in an Evo, for two reasons. One is they predate the introduction of synth oils, which work much better with modern materials and running clearances; two your engine by definition is getting on and is well used! A third reason very simply is that they are not worth the extra expense.

By contrast my S&S Evo is much more recent and they recommend synth oils, although I only use it in the engine.

 

Have to agree, never seen a change in running temps but was a little noisier.....squish ratio's...


[QUOTE=grbrown;13730039]I wouldn't recommend using any synthetic oils in an Evo, for two reasons. One is they predate the introduction of synth oils, which work much better with modern materials and running clearances; two your engine by definition is getting on and is well used! A third reason very simply is that they are not worth the extra expense.

 

This topic usually turns ugly in most forums but always comes back to does synthetic oil make my butt look big in the Evo section.

Will list the results of past debates. Redline Shockproof Heavy in the trans, ATF in the primary and a 50/50 debate of straight 50 in the summer time or basic 20/50. ATF does a good job in the primary and cheap, can change it 3 times compared to synthetic. Synthetic in the trans works as well but Shockproof is some great stuff although is looks like Pepto Bismol, purchased a used Baker gear set and Shockproof was stuck to it like snot and won't run off. Straight 50 helps quiet down Evo's in areas concerning lifters expecially with square lobed cams like Woods and EV27, straight 20/50 gets the job done as a base Evo doesn't create heat that feeds into the Synthetic selling promo.

 

Mobil 1 has been available in the US since 1974. Earlier in Europe.

But I agree there is no advantage in using expensive syn oil in an Evo, it is just a waste of money.

 

My bike doesn't like fully synthetic in the motor. I use Mobil SHC630 in the transmission and Mobil synthetic ATF in the primary, HD non-synthetic in the motor.

 

You've been reading their website! That's true, but it wasn't widely available or used, except I suspect in racing circles. Chevrolet first introduced it in the Corvettes in 1992 and Porsche to their range in 1996, which dates the era of the adoption of much upgraded manufacturing techniques and materials in the auto industry, at the high end. The wider auto industry has only adopted synthetic oils in the last 10 years or so. Even my 2008 S&S engine uses it!

 

Mobil 1 is nothing new, and has probably been around longer than some members here... It has been widely available for 40 years in the USA, they were still putting oil into cans back then.

At the beginning you had to buy at a Mobil station, but they were (and still are) everywhere.

 

Has anybody used syn3 in the transmission and the clutchs. That is all they sell at the hd dealers .