I dont want to start a great debate but can I use the HD primary and transmission oil in the primary and transmission of a 98 Wide Glide?

 

Volks,

Seriously, that stuff is crap. Use Amsoil 20/50 in the Engine and Primary and use Amsoil Severe Gear oil 75/90 or 75/110 or 75/140 (which is what I use in all three of my bikes!) This is the best stuff and your bike will run smoother, cooler and better! Tranny will shift better, less clunk and easier to find neutral!

Glenn

 

There are a couple of threads on this, some folks swear by ATF in the primary, others have their own special brand. I use Amsoil 20-50 in the primary, and also in the xmsn in the winter, and I switch to 75-90 in the summer. Good results for the last 15 years. And like slotbike says, it shifts better.

 

Yes, and it will give you good service.

 

Motor oil and gear oil are rated on two different scales.

75W-90 gear oil is roughly equivalent to 20W-50 motor oil.

Here's a nice viscosity chart (paste it in your browser address window).
.
http://www.bobistheoilguy.com/cms/in...d=48&Itemid=55

 

I put some off-brand type F atf in mine last year after a shifter shaft replacement. I had it, and always wanted to try it. Works fine, and I swear it's easier to find neutral now and doesn't clunk as hard when going into first from neutral. Less fluid drag in the clutch I suppose.

 

ATF is roughly a 20 weight although there is a Redline heavy that's around a 30 weight.

 

You want a GL-4 oil for the primary. That doesn't have slip additive types bad for the clutch.

Why I use Amsoil Automatic transmission oil in the primary. It is a 70 Wt. gear oil good for wet clutches.

Redlind shockproof for the Transmission. 75 wt gl-5 with the highest amount of wear additives on the market. Wonderful for the transmission, would be death for the primary clutches.

3 holes doing 3 completely different things. Why should one type work for all? Why compromise?

The engine gets Amsoil or Redline 20-50 in the Winter and 20-60 Redline in the Summer.

 

Certainly you wouldn't want anything with extreme pressure additives or anything else that may make the clutch slip - but a GL-4 rated lube is not necessary for the primary chaincase. The fact that it's rated GL-4 means that it must have a certain amount of anti-wear and extreme pressure additives to meet the specification.

From the Amsoil web site:
"AMSOIL formulated Synthetic Universal ATF with high film strength (shear stability) and premium anti-wear/extreme-pressure additives"

Amsoil atf is right in the middle of the 20 weight viscosity scale - with a kinematic viscosity @ 100°C, cSt of 7.6. This is pretty much industry-standard for atf fluids.

There's a clutch pack and two double-row gears and a double-row chain in there and it's not a candidate for high-tech lubrication.

Bikes with shared sumps (Japanese mostly) use a conventional motor oil for the combined transmission/clutch and do quite well in this regard.

HD recommends their Formula+ fluid for the xmsn & primary and I've seen more than a few bikes with 100K+ miles using just this combination. Of interest is that this particular lube is roughly a 50 weight oil with virtually no additives and is similar to many of the automotive manual transmission lubes.

Why do folks like using an atf in the primary chaincase? Well it's roughly a 20 weight lube. It's thinner and provides a more positive clutch engagement. It also provides for a more rapid clutch separation which typically provides for smoother shifting. Many of the aftermarket clutch manufacturers recommend atf for their clutches.

What goes into the primary chaincase has much more to do with shift "smoothness" than what goes into the transmission, although that is also a factor.

So try this.... with the bike in gear... pull the clutch and hit the starter button in really cold weather with a fill of Formula+..... It'll take you for a ride.

Try the same thing with an atf or a 10W-40 and it'll sit there - no drag on the clutch.

The vast majority of transmission failures that we see are not due to using the wrong lubricant, but rather from water intrusion. It's amazing the number of people that never change the transmission lube. In my mind it should be changed at least annually, just to be sure.

 

can't say about amsoil, but red line is great stuff. smoother shifts, less clunk, and finding neutral is a snap. Bikes are expensive put the best in it. The 20-50 oil increased the idle speed about 50 or so rpm's on a carbed fxd