This discussion is carried over from the klunking shift thread below, I didn't want to muddle things up there for the OP.


Ok, so... here we go...

First off, I need to point out the following for the doomsdayers...

I'm voiding my warranty.

I'm going to ruin my comp.

I'm going to ruin my IPB

I'm going to ruin my chain tensioner.

Someone's probably going to die.

Saved you the trouble.

I also have to point out, for whatever it's worth, I have a '15 Limited Low. That means I have the CVO clutch, with coil springs instead of a diaphragm spring. It would stand to reason it is made to take a bit more HP without slipping than a standard clutch, (given the 110 in the CVO) but I really don't know.

The first part of the problem is parasitic drag on the clutch disks from the fluid. Even though you pull in the clutch, the plates still want to stick together, and even when separated want to drive one another through the fluid barrier. You can feel it when you cold start the bike in gear with the clutch in, the bike still wants to move. If you start it with the bike in neutral, then shift into first, you get the KLANK, because the mainshaft that should be sitting still is instead rotating with the clutch. In an ideal world, shifting into first with the engine running should be no louder than doing it with the engine off. This is where the ATF comes in.

Most think it's viscosity that makes the ATF work because it's thinner.
There is more to the ATF making the KLUNK go away than just the viscosity. It's not really much if any thinner. It's the properties of the fluid. Designed for auto transmissions in cars, it's perfectly suited for wet clutch operation obviously. Car transmissions are full of clutch plates. I've tried 3 or 4 different formulations, some better than others, and settled on the Mobil 1 synthetic. Another promising ATF is Redline's High Temp synthetic ATF for cars. It has a little higher viscosity than Mobil 1,(and curiously the same viscosity as their V-Twin primary fluid) but works about the same.

Once you start thinking outside the Harley box, you start to do some research. It was car forums that led me to the Redline ATF. But, some folks complain that it shifts TOO firm.

It doesn't slip ENOUGH.

Now get the smelling salts ready for the guys in the back...

The solution is to add friction modifiers. WHAT?? Yep, that same stuff Harley and your mother both told you to avoid. Clutch slip in a bottle, and here it is...


You see, the clutch does need to slip just a little unless you're at the dragstrip. 2 ounces of this, along with 32 ounces of Mobil 1 ATF is THE best combo I have found. (And I have tried Redline primary, Ford ATF, GM ATF, Formula+... the worst, Syn3, Mobile 1 V-twin 20-50, others I have forgotten)

Think about what most people want in a car transmission... smooth easy shifts with no slippage. ATF is designed to provide that.

My Limited Low has V&H power duals & slash cut rounds, Ness Big Sucker AC, and a power vision tuner. It's a STRONG running 103, and the clutch DOES NOT SLIP, believe me I've tried.

Barnett mandates ATF for it's Scorpion clutches, & Mark from Baker has said that their new comp is fine with ATF. I assume both know there are other components in a primary.

So, eliminating parasitic drag in the clutch is part of the problem, the ATF mixture solves that. The other part of the problem is the trans...

There is just no getting past the mechanical design of "dogs" slamming into slots on the adjacent gear. Here, viscosity is king, as it forms a "cushion" between the slamming parts. Again, I've tried most everything.The best I've found is Bel-Ray V-twin. It's thick, and works. But, as with all fluids, it thins with heat so the hotter the temps, the louder the shifts. By and large, non-synthetic works better than synthetic.The worst thing I ever tried is Syn3.

So, there it is. I'm not going to argue, or try to persuade anyone. And as always, you do whatever you do at your own risk. I'm just saying what works for me, and I can tell you my early morning cold shift into first is dead silent, and shifting in general is vastly improved. Finding neutral either up or down is a non issue. I've got about 3000 miles on ATF with no issues, I'll be the first to post here if that ever changes.

Have a nice weekend.

 

Thanks for the review, I am also using Bel-Ray in the primary,transmission, and engine. Works good for me.

 

Your comment about clutches slipping or not at the dragstrip shows your ignorance. Sorry but you're wrong on that one. Slipping clutchest at the dragstrip is what is giving the crazy speeds that are being shown in Top Fuel down.

 

Amazingly, I get those same smooth easy shifts and proper clutch operation, all while using Syn3. Along with proper lubrication without having to mix fluids.

But that is me, you all are free, of course, to run anything you want, including water if that is what you decide. ATF for sure caused much problem in the first version of the SE compensator with galled and rusted hubs. With the new version using directed oiling maybe not as much of a problem, but just do not see the purpose of ATF. I start in gear all the time with no trouble with Syn3. Only when the bike is cold is there any drag and it is not much. Clutch adjustment has some bearing on clutch drag, too. In my opinion use of ATF is a solution looking for a problem.

 

Hey Bikerscum, i've been in the game for several decades, and your post is your perception, which we all have the right to express. i just think i'll contiue using Redline shockproof heavy in the trans, B&M trickshift in the primary/clutch=chaincase, and syn-3 in the motor. i'm really glad that you feel the need to "enlighten" us mere mortals. maybe we don't have a clue, but for me, i'll stick to what i know works.

 

Very interesting review. On a side note, someone tell me why the clunk is a problem? I've been riding a Harley and clunking for 19 years. My Sportsters used to clunk too! Now if my bike grinded gears, that would be a different story!

 

Wal-Mart 20W-50 dino oil at $2.59 a quart every 5,000 miles and I still run the oem original clutch plates all these years later w/o issue. (God I love my old bike.)

 

In my experience, a properly adjusted clutch and proper oil level makes for a very minimal "clunk" and neutral is easy to find. That being said, I ran atf in my softail years ago and the clutch plates themselves do perform the best with the atf. There is way too much going on behind that primary cover that needs more lube IMO though. I'm not going to experiment with my Street Glide.
Good luck

 

WOW..too cool. Gotta get me some of that...Just for that, I will share my secret witches brew.... I use this in my new twin cool and have never had a leak like all the others have.......

 

I run atf in the primary with my barnett clutch. B&M trick shift. Works great. Bel ray gear lube in the tranny an napa 10/60 synthetic in the 120R

The atf holds up well behind the 120R with no slipping.

Works better than any oil ive tried in the primary