clutch slipping
Road Captain
Joined: Oct 2007
Posts: 634
Likes: 8
From: Plum & Nearly
I'm not going to debate on oil, and obviously use what you want.....
Do automatic transmissions in vehicles not have the same wet type clutch packs and similar electronics (sensors/switches/solenoids) in them? They have run countless miles with ATF. Bottom line is you need a little lube for the chain and roller bearing in the primary. The rest is for cooling. If the rotor/stator can survive engine oil or Formula +, I think it's reasonable to believe that they can take ATF as well.
BTW, ATF (especially type F) is designed to work with wet clutches and therefore doesn't have the "friction modifiers" that everyone screams about when trying to say car oil won't work in a motorcycle. Again, FWIW and YMMV as always....
Do automatic transmissions in vehicles not have the same wet type clutch packs and similar electronics (sensors/switches/solenoids) in them? They have run countless miles with ATF. Bottom line is you need a little lube for the chain and roller bearing in the primary. The rest is for cooling. If the rotor/stator can survive engine oil or Formula +, I think it's reasonable to believe that they can take ATF as well.
BTW, ATF (especially type F) is designed to work with wet clutches and therefore doesn't have the "friction modifiers" that everyone screams about when trying to say car oil won't work in a motorcycle. Again, FWIW and YMMV as always....
And I am not so much concerned with the "friction modifiers" in ATF BUT what I am concerned with are the chemical compounds of the ATF having an adverse affect on the electrical components in a H-D, not an auto trans, and the ability to adequately lubricate where needed.
I am not willing to risk detonating my primary when it appears that the only attribute to running ATF is a couple of bucks.
Respectfully, TC
Outstanding HDF Member
Joined: Jan 2008
Posts: 3,328
Likes: 15
From: Pacific Northwest
ATF is not designed primarily for lubrication - it's designed for cooling. As such it is exactly what a wet clutch needs (read HD primary here). I've had zero problems running ATF in primaries for the last 25 years (countless miles and 8 different HD's). It does not adversely affect anything in the primary. If your clutch is slipping it's due to weak springs and/or adjustment. I do recommend the SE spring for anyone having a slip issue. Much less expensive than a VP and very effective for all but the highest HP engines. Mine makes over 100/100 and hasn't slipped since I installed the SE spring. Lever pressure is stiffer but far from obnoxious - only becomes an issue during stop and go parade type activities.
Road Warrior
Joined: Mar 2011
Posts: 1,456
Likes: 132
From: Deep South, Louisiana
Dont use full synthetic in primary, use what type oil that is called for. ATF is for automatic automotive transmissions not a primary. Will take a few miles to get that ATF out the plates before it stops slipping.
Last edited by K Melancon; May 29, 2012 at 09:42 PM.
Stage II
Joined: Dec 2013
Posts: 2
Likes: 0
From: new zealand
hi ppl im new to Harleys and to the forum..was riding my bike and clutch was fine,,,got on the beast 10 min later to go home and the clutch was slipping to the point I had to get towed home..wats up with this??????? thanks
Road Warrior
Joined: Jan 2010
Posts: 1,290
Likes: 20
From: Salem, Or
Any mods to the engine? The 07 has the easy pull clutch diaphram spring. After I added my cams, at full throttle in 6th gear, the clutch would start to slip at around 90mph. I made the mistake of adjusting the clutch hub when the clutch was warm and I also ran royal purple atf. I didn't like the actuation and the slip was slightly worse. I readjusted with it cold and went with dino valvoline 10/40 motorcycle oil and it was much better but would still slip under heavy load. I liked the easy pull clutch so I went with a VPC clutch (here's the link: http://www.aim-tamachi.com/home.php ) and no more slip, still have easy pull and it's supposed to be good to 120 ft. lbs. of torque. If I need more tension, I can go with a stock 04 and earlier diaphram spring with kevlar plates and be good for even more power. The only drawback? Cost. About $300. Make sure you have your clutch adjusted at the primary cold with the clutch cable adjusted all the way slack.
I just went to a 103 with comp set at 10.2/1 along with TW555 cams and while rolling on the throttle getting on the freeway as soon as I shifted to 6th the clutch would slip. I installed the AIM VPC pressure plate and all is well.
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Cruiser
Joined: Jul 2011
Posts: 130
Likes: 9
From: NorCal
ATF might be good if youre a weekend warrior or drag racer. For guys that ride almost every day, not so.
I put B&M Trick shift in my primary, In the 7,000 miles i had that crap in there i adjusted my clutch 3 times. It was slipping bad.That was the recommendation from an engine builder. "If you want your clutch to last put B&M trick shift in there"
Since putting Rotella 15-40 in, an additional 29,000 miles, my clutch has not needed adjustment since.
I put B&M Trick shift in my primary, In the 7,000 miles i had that crap in there i adjusted my clutch 3 times. It was slipping bad.That was the recommendation from an engine builder. "If you want your clutch to last put B&M trick shift in there"
Since putting Rotella 15-40 in, an additional 29,000 miles, my clutch has not needed adjustment since.