Best Oil for Harley Transmission Reviewed

Red Line has a lot of trusted customers, especially among motorcycle riders. And we recommend their V-Twin transmission oil with ShockProof. The ShockProof naming is there because the oil viscosity is thicker than standard transmission oil, and this property will help dampen vibrations from everyday use.

It will prevent any damages caused by shock due to hard shifting. And while driving, you can notice the difference in transmission and engine noise. You’ll have less transmission noise and more confidence in driving.

Since this transmission oil is thicker than conventional transmission oil, it will also provide a much more effective cooling property for a longer time. Due to the thicker viscosity, the transmission oil will have a much thicker film of oil on your gears.

That thicker film will protect your gears from clunking and colliding with each other eliminating clunky shift noises, and the gears will have a much longer lifespan. And lastly, being a thicker transmission oil, gear jumps will also be much rarer.

In the end, all I can see more benefits than drawbacks with this transmission oil. This oil will essentially work with every Harley Davidson model, even models with the Twin Cam engines and Evolution engines will work well with the Red Line V-Twin Transmission Oil.

This oil is best for people who love to push the engine and transmission to the limits.

Did you like both transmission oils we’ve mentioned so far? Then this last one may be the best for you as it brings the best features of the two previous oils together.

The Spectro Oil R.HDPG6 is a heavy-duty transmission oil aiming to provide a better shifting experience and a quieter transmission noise. The SAE rating is at 75W-140, making it highly versatile, as you can use this well on weaker transmissions while it’ll handle high-performance transmissions better. As we all know, high-performance transmissions will only go well with heavy-duty thick oil as they resist thinning better.

The Spectro Oil R.HDPG6 is made to exceed all OEM and Harley Davidson warranty requirements on fluid replacement, so you can rest easy that this will not void your warranty in any way. This oil has additives that’ll help maintain clean gears. It also makes a high strength film between the gears that’ll also prevent the gears from jumping and therefore shift more smoothly. And with the thick oil, the gears will be protected from having shock loads.

Overall, the Spectro Oil will work for everyone, and if you doubt what to get, this might be the safest one to get for your transmission.

Similar to the first one, the Maxima Racing Oils has a dedicated oil made for V-Twin transmissions. This is a mineral oil instead of a synthetic one, so there might be differences, but let’s take a look.

It is known that high-performance transmissions and engines will also need high-quality oil, which recommends synthetic oils the most due to their controlled formulation. The transmission oil we’re taking a look at today is mineral-based. Does that mean it can’t be used on high-performance engines? Well, not necessarily. In particular, this oil is highly refined and has additives that help it achieve an SAE rating of 85W-140, which is the best rating for transmission oils if you’re using mineral oil.

Due to the thickness of the oil, this is best for 4-6 speed transmissions found on high-performance transmissions as using this on low power engines will lead to inefficiency.

One of the additives on this oil is detergents that hold in and neutralize dirt deposits found on engine components, helping prevent the gears from wearing out. Other than that, the thick oil will also promote smoother shifting even under sudden shifts in high RPMs

As an end note, this is indeed one of the best you can use for your Harley. While it can work on most Harleys, you should proceed with caution as some Harleys, especially some of the high-performance ones, will specifically ask for synthetic or even fully synthetic oils. If your manual clears it, then this oil is worth the try.

Did you find these oils interesting? You can find out more using the links above. And remember to take a peek at your user’s manual first to find out what your transmission needs. Buy yours now to protect your transmission and enjoy riding more!