This article appeared in the 48th Edition of the Busted Knuckle Chronicles 2008
by Brian Stuart
Toys for Big Boys Moncton NB
To SYN or Not To SYN
One of the questions we get a lot on HTT as well
as at our Dealership is “ Should I switch to Synetic
Oils “ ?
There is a lot of talk about the advantages or
disadvantages of a Syn oil ... the general
consensus is that its a better oil...lasts longer and
lubes better then a normal base oil...
HD uses a full syn oil in the CVO bikes
(Screaming Eagle ) in all three holes... it performs
great and we see no issues with it... they use the
Harley Screaming Eagle Syn 3 oil... if the bike
comes with a full syn in it...you should have no
I have seen and heard of a problem however if
you are changing from a normal gear oil to a syn
transmission oil ..it seems that the syn oil some
times does not mix will with the remaining
standard oil residue left in the transmission and
you can get premature wear on some parts...
Some Manufactures actually recommend that if
switching to a syn in the tranny ..you first flush or
even dissemble the tranny and wash off all parts
with a solvent to remove any residue to avoid
this... in other places such as engine or primary
this does not appear to be a problem .. remember
that a normal oil for a HD transmission is the formula
+ and this is a Semi Syn oil ... with additives
to help lube the gears etc.
In any case if using a syn oil buy a good
quality brand I like the HD Syn 3 ..it works well,
other good brands are Mobil 1 or Amsoil ..and
a popular one on HTT is RED LINE ....one big
misconception about using a syn oil is that you
can run it longer between changes ... this is a big
mistake and where some issues arise.
The manufactures recommended change
intervals should always be followed ...oil gathers
containments as its run in any engine and they
build up over time... a syn oil may not lose its
additives as fast as normal oil but it holds acids
from combustion and wear particles from the
engine the same as normal oil.
Change it often and use a good filter .
Ride Safe and Ride informed with