Picking a primary oil, and theres just so many opinions.

I don't want notin fancy

Dex/Merc ATF is easily available in my area, Type F isn't.

I have Dex/Merc by the gallon for my trucks.

Anyone have a good reason NOT to use Dex/Merc?

 

Most people running ATF in there primary have upgraded primarys / clutch and the manufacturer requires ATF. For stock primarys you will be much better suited using a primary specific oil or any oil that's wet clutch compatible. One thing is for certain , pick a good oil and stick with it. Wet clutches do not like different oils thrown at them in a short period of time.

 

Don't put ATF in the Primary. Unless you are running some aftermarket clutch that requires it. To thin a lube. Have you noticed HD is now recommending their 80W140 gear oil in Primary.;

 

in my 85 I have used. Harley primary oil, 10w30 motor oil, 10w40 motor oil, 20w50 harley motor oil, 20w50 "racing oil" from my local farm store, and ATF type f. to tell you the truth I couldn't tell the difference in any of them. the 85 is over 100k and I still have all the original clutch and primary parts in there. basically, all the oil does is lube the chain.

 

Many threads exist regarding ATF in the primary. Some advocate it, some warn against it.

I have been using Mobil 1 Synthetic ATF in my 2012 primary for about 12k miles now. I have experienced no problems with it and I love the way the bike shifts with it.

A caution voiced by some is the risk of the ATF not being "heavy enough" to adequately lubricate the sometimes problematic engine sprocket shock compensator assembly inside the primary. So far, I have been okay.

My bike was a low-mileage 96-inch Super Glide Custom that I upgraded with a pair of stock H-D flat-top 103 HO pistons and cylinder boring. I milled the heads slightly, dropped in a pair of SE204 cams, attached a V&H Upsweep exhaust and topped everything off with a V&H FP3 tuner.

The result was a vastly more powerful engine that caused my stock clutch to slip under the more robust acceleration that resulted. After research, I installed an Alto Carbonite extra-plate clutch and retained my stock light-pull clutch spring. That's when I began using the Mobil 1 ATF.

I have no more clutch slippage. The bike runs like a scalded dog and shifts very nicely. The clutch release and take-up is fantastic. The Alto plates and the light springs really create a great feel.

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i stick with factory, after all they did all the R&D.
when it comes to atf, there is a new sheriff in town and the fluid is designed for chain/belt drives and that is "CVT" fluid, more expensive than atf.

 

I like to use amsoil ATF mixed with amsoil primary.i think ATF alone is to thin. I've tried a few and I always go back to this as being the best for wear and feel. To me the primary is the only one u can tell a difference in what is run in it.

 

Your clutch dictates the fluid in your primary. If you are running all stock put something basic in there that Harley recommends. If you are running an aftermarket clutch or clutch plates then run what they say. I run Rivera Primo Pro clutches and always use Type F, but don't just randomly throw different fluids in there if your set up is not calling for it haha

 

Primary drive systems are not all the same, in years past (4 and 5 speed) ATF was used by many, including me, with no problems.

Since the new compensator system came about, with it`s sometimes problematic wear problem on the ramps, ATF may not be the best choice...

I`m using Formula+ in my 6 speed bike, the old `89 Softail gets 20w50 motor oil.

 

Sound exactly what I'm installing in my 2012 103ci FLHR. Year after installing Stage II at 16k clutch started to slip rolling on 5th gear. Long story short ordered ALTO Carbonite clutches and slightly heaver 37807-3(364 lbs. F) 2007 thru 2010-103 ”Police" Clutch Spring. Now looking to either going with Mobil 1 Synthetic ATF although ALTO suggested Redline Synthetic ATF. Decisions, decisions....

B Bop

2012 FLHR (Road King) Stage II Red Ember Sunglo/Merlo Sunglo, Original HD Chrome Laced Profile Aluminum Spoke Tubeless Rims, ABS, Cruise Control, Security Package, Saddlebag LED Spoiler lights, and array of nostalgic & performance accessories that enhances appearance & blood curdling performance.