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Question on HD engine fluids?

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Old Mar 29, 2011 | 01:09 AM
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I changed the oil on my new RGC 103 at 500 miles, and all three fluids (oil, primary, and tranny) were changed at the 1k service, but I intend to do all future fluid changes myself. I've had a number of motorcycles over the years, but this is my 1st Harley, and 1st bike that requires three different fluid changes. I'm not asking about the Engine Oil, as that's the easy part. I'm mainly asking about the Transmission and Primary Fluids. From what I see on the HD link below, they appear to be the same fluid. My 1st question is.....Am I correct?

http://www.harley-davidson.com/gma/g...bmLocale=en_US

I'd like to change over from HD lubricants to Amsoil lubricants at 4k-5k miles. The maintainence schedule says not to worry about the Primary fluid until 10k, but I'd like to at least do the Oil and Tranny fluids at the 4k-5k mark. So my 2nd question is, I know which oil and filter to get, but which Amsoil tranny fluid should I get from those listed on the link below?

http://www.amsoil.com/a/synthetic-transmission-fluid
 
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Old Mar 29, 2011 | 05:14 AM
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Your bike came from the factory with HD Formula+ in the tranny and primary. I don't know exactly what it is but I do know that it works GREAT in the primary, as good as anything else people are using. As far as the transmission, I prefer something else. IMO, the best Amsoil product for a Harley 6 speed tranny is their Severe Gear 75w140.
 
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Old Mar 29, 2011 | 08:07 AM
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I'm running the HD Formula+ in primary & it works great.
 
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Old Mar 29, 2011 | 08:19 AM
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I like Redline trans fluid w/shockproof. I use redline in the primary & engine. I noticed a real difference in switching from stock HD trans fluid to Redline w/shockproof. Just my opinion though.
 
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Old Mar 29, 2011 | 08:20 AM
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If you run Amsoil in the tranny go with Severe Gear 75/90 or 75/110
 
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Old Mar 29, 2011 | 08:43 AM
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Originally Posted by Tek74
The maintainence schedule says not to worry about the Primary fluid until 10k, but I'd like to at least do the Oil and Tranny fluids at the 4k-5k mark.
i think you're going about this backward. the manual says 20k on the tranny and 10k on the primary. i would worry about the primary before the tranny.

i know you wanted suggestions on the amsoil oils, but i don't use them. i use either drag spec primary, or formula + in the primary, and 75-90 gear oil in the tranny.... don't know what amsoil has for the primary, but i'm sure they have some kind of snake, i mean gear oil......
 
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Old Mar 29, 2011 | 08:59 AM
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I hear you. I guess I'm just a little overly eager to keep all the fluids fresh early in the engine life. I may even change all three fluids agains at 5k, then start following the manufacture mileage recommendations after that. My specific thing with the tranny fluid was that I've heard claims of guys using after-market fluids that were supposedly much better than HD tranny fluid.
 
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Old Mar 29, 2011 | 09:12 AM
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I tried the amsoil in the tranny it was good but I have found that I like the redline trans fluid better. I have also went to the redline fluid in the primary. It gets rid of that pesky clunk when you first shift into gear. Also I have found less wear on my clutch pack as well. In the motor I use mobile 1 vtwinn from walmart cheap pricing. always works great. I have broke down many motors with many different oil that have been run and after looking at the parts I run mobile 1 oil in my bike.
 
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Old Mar 29, 2011 | 09:23 AM
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Harley isn't exactly forthcoming with information. However, the "stock" Formula+ tests out as a 50W mineral (motor) oil. The upside to a single-weight is that its viscosity drops more slowly than a multigrade's would. The downside is that it's too thick when the engine is cold. This can cause hard shifting until the primary warms up.

75W-90 gear oil is the same viscosity-wise as anywhere from a 10W-40 to a 20W-60 motor oil, but with a different additive package designed for gears. 75W-140, likewise, is equivalent to anywhere from a 10W-60 to a 20W-somethingthatmotoroilscan'teventouch (AGMA 7 or 8), again with a different additive package.

Personally, I'd suggest a 75W-140 for the transmission, preferrably a quality synthetic such as Mobil 1, and 75W-90 for the transfer case. Unless you use short change intervals, in which case 75W-90 for both.
 
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Old Mar 29, 2011 | 09:25 AM
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Originally Posted by Bushpilot
I tried the amsoil in the tranny it was good but I have found that I like the redline trans fluid better. I have also went to the redline fluid in the primary. It gets rid of that pesky clunk when you first shift into gear. Also I have found less wear on my clutch pack as well. In the motor I use mobile 1 vtwinn from walmart cheap pricing. always works great. I have broke down many motors with many different oil that have been run and after looking at the parts I run mobile 1 oil in my bike.
+1 exactly what I do ... drastic improvement in transmission and clutch.
 
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