Trying ATF in Harley primary

Status
Not open for further replies.
Originally Posted By: MoreCowbellAz
I've heard occasional complaints about the newer compensators as well, not sure if it's fact or myth tho.

Back to the ATF feel, I did a lot of riding over the weekend at full temps (was warm here in Phoenix), and I'm loving the smooth clutch feel, doesn't change a bit even after long ride.

The newer compensators have belleville spring pack that fail, since part of the rotor and not separately serviceable expensive repair. This has been redesigned and the new one has replaceable spring washers. Big one time expense as new rotor, new compensator and springs. But then a under 100 spring pack when they fail.

Not oil related, not overheated.

Rod
 
Im not so sure if a smooth clutch is good or not. But I do understand their are A LOT of Harley people using ATF.
I personally like a grabby clutch feel, I like the feeling of positive engagement. I cant help wonder if the smooth feel is due to less grip. With the Metic bikes I owned I always used the oil with the most grabby feel.
In my Road king I am still using Formula+

Im less of a skeptic as far as manufacturers recommending, in this case, motor oil over ATF fluid. Im sure Harley must have a reason recommending what they do since they build the bike and I spent a lot of money on it, Ill trust the engineers same as I would for my automobiles.

Ex. If a manual transmission called for motor oil, I wouldnt use gear oil and I guess I feel the same about the primary fluid. Maybe more so if the thing should blow apart, although unlikey, it may affect my warranty (i have 4 more years) and in that case not sure if I would blame them.

I will say I am confused about your statement that your primary fluid comes out clean. Although I run mine up to 7k to 8k miles mine is always filthy. I have over 15K miles on the bike now
 
Last edited:
A grabby clutch feel is not good on a decent hill waiting for a red light to go green. A Harley clutch properly lubed and set up properly. You should be able to hold the bike on the hill by lightly engaging clutch.
 
Originally Posted By: xl2006
A grabby clutch feel is not good on a decent hill waiting for a red light to go green. A Harley clutch properly lubed and set up properly. You should be able to hold the bike on the hill by lightly engaging clutch.


^^^^ agree I didn't mean grabby to the extent of interfering with operation if the bike.
On my metrics I did notice some oils had a more slippery feel. I preferred a more solid engagement feel, maybe grabby was the wrong word.
 
Last edited:
Regarding the smoothness, I hear what you're saying, I would think smoothness is a function of how the plates' grip tapers off, if that makes sense. I like a positive feel, but one that has a smooth transition from engaged to disengaged. If you like that window to be small I can see where ATF might not be your ticket. On my bike, what got me thinking to experiment is I'd get a slight courseness or shudder when releasing the clutch slowly, not a big deal but noticeable. That disappeared with ATF. As long as there no negative side effects, I prefer that feel. I don't have issues with the clutch actually slipping.

Regarding my primary fluid coming out clean, I wouldn't say perfectly clean as when it first went in, but I expected it to be opaque and it wasn't, it was only a little discolored and I didn't see a bunch of fibers or grit in either the oil or on the drain plug. To be fair, I don't know for sure if the clutch plates are OEM or aftermarket, or even if they're original, but in any event the clutch works great and the plates aren't shedding a bunch.

I'm curious to see the ATF when I drain it this next time, I would think that red color would show dirt better than the amber colored HDEO I had in there before.
 
You said it best.. "small window" for me. It does sound like it's working good for you though.
I'll pay more attention to how dirty on the next primary change too.
From what I remember it wasn't pretty but bike was still on the new side at 8k miles or so, if I'm remembering correctly.
 
Last edited:
UPDATING……….I said I'd report back. I dropped the ATF (Valvoline Dex/Merc) that was in the primary after 4900 miles, and the drain plug looked real good, there was a small amount of that grey paste looking stuff on the magnet, I'd say no more than half a BB if you can picture it rolled into a ball. That's seems to be reasonable based on what I've seen in the past. No other odd shards or artifacts. Based on this I'd say there was no excess wear going on. FWIW my bike is a 2000 RK which has the old style compensator which seems to be the robust version.

The fluid that came was definitely not clean and clear, but it wasn't burned and black either. It was more like a semi opaque dark maroon color. Nothing much to see there, which is good.

Throughout the OCI the clutch feel never change a bit, the engagement was silky smooth the whole time, finding neutral never a problem, and no bang going into 1st gear hot or cold. Sometimes barley a click, sometimes maybe a slight snap, but never a bang. I think that's about as good as this bike will get. Shockproof Heavy does a good job to keep the general shift action good.

For this OCI I filled with Mobil 1 Syn ATF. After a few hundred miles I can say it feels about the same, which is to say really good. Maybe a tiny bit better going into first, not sure, it may be the placebo effect. Seems the same as far as clutch feel goes. I went with the Mobil 1 mainly because its a synthetic and I ride all year round which means from like 32 to well over 100 (aka free kin hot), and I wanted something that withstands heat well. I also use the same fluid for my suspension front and rear, similar reason; I wanted a synthetic to minimize the viscosity variation from hot to cold to try to keep the suspension feel consistent. Using the same ATF for everything appeals to me from a simplicity point of view.

Anyway, I find the ATF works good, at least for my bike. I feel pretty comfortable with it. I could get talked into going back to 15w40 too, it's just a couple ticks off on the feel side of things. Personal preference thing.

Tell ya one thing…….I hate that old style primary drain bolt (no head, no taper, no o-ring), you could screw that thing right through the cover if you wanted and never be sure you get a great seal. I had to break down and pull it the other night, which meant dropping the ATF obviously, just so I could re-wrap it with teflon tape to solve this blasted weep. I thought 4 wraps would be plenty………nope. Try like a least 7, going in the correct direction only, nice and even the entire length of the thread, and make sure the bolts is 100% oil free before you apply the tape. Finally got it. Those oil weeps drive me absolutely batsh** crazy.
 
Really appreciate the great testing and report out you did on using ATF in the primary. I've been using Mystik 15W-50 in all three compartments and it has worked well. Shifting and neutral finds are good but I would like to see if I can get rid of the clunk when I first start my Street Bob and put it in 1st. This is the only time it happens. I'm also curious about the impact on shifting.

I plan to give ATF a try when the weather gets warmer!
 
Yep doesn't hurt to give it a try, I'm guessing you'll notice a difference. I'm at 5,500 mi on my current fill of M1 Syn ATF, still feels exactly the same as when I put it in, so the good feel definitely isn't short lived. I continue to like it.

Shoot I use the same stuff in the suspension too, I have it in my forks and shocks, works great. In fact just last weekend I did a fork oil change in my RK and used the M1, there's something gratifying about getting the old stuff out and installing some nice clean red cough syrup. LOL. The old fluid had 14k on it which was probably a little early from the looks of it, I'm thinking 20-25k would have been about right. Longer in the shocks for some reason, I always find more grime in the forks.
 
Originally Posted By: gman2304
I use 15w40 HDEO in the primary and Redline shockproof heavy in the transmission. Shifts like butta with no false neutrals.


ditto
 
Originally Posted By: Bellavita
Really appreciate the great testing and report out you did on using ATF in the primary. I've been using Mystik 15W-50 in all three compartments and it has worked well. Shifting and neutral finds are good but I would like to see if I can get rid of the clunk when I first start my Street Bob and put it in 1st. This is the only time it happens. I'm also curious about the impact on shifting.

I plan to give ATF a try when the weather gets warmer!


You get the clunk on start up because the clutch plates have little to no oil between them allowing the slip that is needed between the fiber and steel plates. It is in effect your clutch is not releasing like it should by not allowing the needed slip between the plates. So your clutch is dragging and the trans gears are turning as the engine is running. You put it in gear and the clunk you hear is the dogs on the trans gears slamming in to each other while they are turning. Start up the engine in neutral and and let it idle while you get your gloves and stuff on and situated. Still in neutral pull the clutch in and let oil get in between the plates to get lubed up. Let the engine run in neutral with the clutch pulled in and give it a minute like that and then put it in first gear. When ever I stop and put the trans in neutral and then need to go in first gear I pull in the clutch and take a two or three second count ( depending on your particular engine/trans) and then drop in first,,,,,result is no clunk or barely audible engagement, that pause will give the trans gears time to stop turning.

When the bike has not been ran for a day or so the plates drain off most the oil between them. Another thing you can do is start up the engine and let the oil pressure build and warm up the engine and when you are ready to shove off,,shut off the engine put it in gear and and then start up the motor. You only need to do that on the first cold start up you make for the days ride.
 
Probably a different strokes thing, and I agree for the most part with the things you can do to reduce the clunk, but think the reasons behind it have more to with the oil between the plates creating a suction effect when the oil is thicker, thereby making the plates stick together more, rather than it being from the plates being too dry from the oil draining off. Kind of like when you soak new plates in oil before installing, you have to pry them apart a little to get them separated. Dry plates don't stick together at all. Same with a dry clutch. Anything you do to dislodge the plates with have the same effect of avoiding the clunk, it's just that thinner oil makes all those methods easier compared to think. ATF is exactly that, thinner than most any motor oil you'd run in a Harley. That's my rationale anyway, for what it's worth. I also think there's a good chance that thinner grade could me a good thing for some of the compensator issues you hear about, although I wouldn't want to have to try to back that one up with data, I have none. It does have some logic behind it though
 
Agree, I believe the clunk is very simple.

Its the drag of the extra thick cold oil, so even when you pull in the clutch, things are still spinning freely and the transmission "clunks" into gear.

The ATF at full operating temperature its viscosity is about equal to around a lighter 30 weight motor oil running in a device calling for a 50 weight and suspect why of course less drag when the ATF is cold..
 
I count to five after pulling in the clutch and then shifting into 1st gear. Most of the time I can't even hear or feel it go into gear. I ride with a friend who shifts his into neutral at stop lights. When the light changes, it sounds like he's using a sledge hammer to engage 1st gear. I haven't said anything because that's the way he does it and it's his bike.
mad.gif
 
I sort of wait a second or two myself, even more so, from a cold first start of the day, more so when its cold outside.
Warmer weather I dont really think about it, I think ... :eek:)
 
Ok so please bear with the elementary question as I am new to motorcycles as well as Harley derived platforms. I have a 2009 Buell XB12r and know it is a 1203cc engine worked over by Erik Buell.

My question here is we are actually talking about not using oil in the primary case. The oil is in the swingarm and the primary oil of course in the case. Currently am just running 20w-50 in both spots. Approx 2.5 qts in swing arm and 1.5 in case. Making sure I am reading this right and wont grenade my bike when the weather is not raining here to bring it out.

Thank you
 
I would not use ATF in your Buell. Different primary setup than the big twins. You are lubricating your gears and clutch, were a big twin has a separate gear case.
Continue with what your using and you will be fine.
 
Originally Posted by LC
I would not use ATF in your Buell. Different primary setup than the big twins. You are lubricating your gears and clutch, were a big twin has a separate gear case.
Continue with what your using and you will be fine.


Agree. FWIW on the Sportsters I service I recommend the Harley stuff (Formula +), but 20W-50 seems to work well also for close to the same price.
 
Originally Posted by LC
I would not use ATF in your Buell. Different primary setup than the big twins. You are lubricating your gears and clutch, were a big twin has a separate gear case.
Continue with what your using and you will be fine.


I run atf in my buell, works great, shifts smooth and a lot less clunking when shifting into first. AFT is designed to lubricate gears inside transmission with wet clutch, seems fitting in this application.
 
Last edited:
Status
Not open for further replies.
Back
Top