ZDDP Zinc Additive

[Alberta Patriot]

Been reading articles about adding ZDDP additive to older engines for extra protection, because of EPA mandated reduction of Zinc in modern oils to protect Cat Converters. Any harm in doing so??

[Pete]

Harm? Not if you do not add to much.
It does make clean up on engine rebuild more of a job as it leaves a deposit on the inner surfaces.

[Alberta Patriot]

Harm? Not if you do not add to much.
It does make clean up on engine rebuild more of a job as it leaves a deposit on the inner surfaces.

Think I'll be too old to ride by the time my engine needs a rebuild.
I am however concerned about added wear to the Transmission because of less Zinc in the oil.

[Robert]

I am however concerned about added wear to the Transmission because of less Zinc in the oil.

You will probably be to old for the trans also, so I would not put in the zinc additive. There are other additives in the oil that will keep it good enough for the transmission. Not to mention the bikes were designed to run on dino oil so by the use of synthetics you already are ahead of the game.

[98valk]

as mentioned too much causes all kinds of problems.

some diesel oils are still maintaining enough phosphorus and zinc.  see my post and check out
http://pqiamerica.com/HDEO_Sample_Summary_Dec_2016.html

as last tested NAPA and supertech are still high as are some others.

[Mr Whiskey]

Have run 4oz's every oil change for years. Smooths those "clunky" square cut gear changes right out. That's why I run it, Wing never shifts as smooth without it. Did a couple of oil changes & waited a day to add it (jus' as an experiment), makes a noticeable difference to me immediately.
Tried the stuff Eastwood sells & didn't care for it much so went back to the original. These days you're lucky if you can find it for +/- $10 so this isn't a bad deal on it...
https://www.amazon.com/ZDDPPlus-Engine-Additive-Phosphorus-Bottle/dp/B006LBAAD4/ref=lp_15987186011_1_1?srs=15987186011&ie=UTF8&qid=1541894646&sr=8-1
P.S. Thanks for reminding me, down to last bottle gotta order
   

[98valk]

Have run 4oz's every oil change for years. Smooths those "clunky" square cut gear changes right out. That's why I run it, Wing never shifts as smooth without it. Did a couple of oil changes & waited a day to add it (jus' as an experiment), makes a noticeable difference to me immediately.
Tried the stuff Eastwood sells & didn't care for it much so went back to the original. These days you're lucky if you can find it for +/- $10 so this isn't a bad deal on it...
https://www.amazon.com/ZDDPPlus-Engine-Additive-Phosphorus-Bottle/dp/B006LBAAD4/ref=lp_15987186011_1_1?srs=15987186011&ie=UTF8&qid=1541894646&sr=8-1
P.S. Thanks for reminding me, down to last bottle gotta order
   

I think u meant "Straight cut gears".   what oil do u use?

[Mr Whiskey]

Tomato/tamato...
Rosmella T6

[Quasi (fmr. GHSTDG)]

+1 for T6

[¿spoom]

What does zinc do to the clutch plates? Just curious, I have no idea.

[Pete]

Zinc being an anti wear additive it attaches itself to metal and resist wear.
It does not add a slick surface like moly does I have never known it to affect clutch material.
It will coat the metal surfaces of the plates and retard wear as the plates (tips) move in the basket