Primary Oil
 

I'm getting ready to do my 1k mile service on my 10 EGC. I was going to use M1 20w50 in the motor, Redline in the tranny but I'm still unsure on the primary. I was thinking I would just do the M1 20w50 in the primary also but heard a few people were doing Auto transmission fluid. Whats best? I already have the M1 purchased so that would be easiest. Any downsides to using the M1 20w50 in the primary?

Thanks

I like using Formula + myself.

http://www.harley-davidson.com/gma/g...bmLocale=en_US

Many opinions on this, almost as many as on engine oil. Here's my experience -

Used 20-50 for a while and had tons of clunk and didn't really like the feel of the clutch.

Switched to Formula+ and was much better.

Since I can't leave anything alone (and after reading about it here), I then switched to Type-F (pick the brand you like) and am really happy with it thus far. I decided on it over the Dex III due to no friction modifiers in the Type-F, and seeing Type-F recommended by a few different clutch disc manufacturers. No slipping and good feel in slow speed maneuvers. With a good clutch adjustment, I don't get any first gear clunk despite what others say. B&M Trick Shift has been mentioned as well, and the bottle says it is suitable for a transmission that specifies Type-F. Valvoline was 1/2 price of B&M so I used the "less is more" philosophy on it.

I think, like many others, that M1 (or any other high tech synthetic) is probably overkill in the primary. The main function of the oil in there is cooling the clutch pack and providing a little lube to the chain and bearing. So a high tech oil isn't necessary, but does make it simpler just to dump in the same oil as the engine and be done with it I guess.

I have been using Type F in my RG for a year or so now with no issues at all. The cost is a lot better too.

I run B&M trick shift ATF and its always performed well for me. I had in my last bike too.

I've heard of guys running conventional motor oil, automotive motor oil, and doing fine in the primary for 10k. Probably works just fine. I have syn 3 in mine, all 3 holes, and it's fine, but overkill on the $. Gonna try ATF or conventional oil, gonna do more research though.

Redline 20w50 in motor, Redline Shockproof in tranny and Redline MTL in primary.

B&M Trick Shift...been using it for 3 or 4 years...no complaints.

Here's what I found when I decided to use Mobil 1 in my RK.
http://www.mobiloil.com/USA-English/...T_Primary.aspx

I use Big Twin primary oil its better than the 20w-50 amsoil, Formula 1, and syn 3. IMO, its seems to coat the chain and gears better and the clutch application is nice and smooth and the whole operation is much quieter. Thinking about using B&M quick shift that stuff works great in my racecar.

+1 on that. Shockproof in the tranny proved to be a big improvement. Easier shifting, finding neutral was easier.

M1 20/50 in my primary since the first fluid change. Haven't noticed any downside, but I have never used anything else.

As was mentioned, there are many opinion's on this subject. I can tell you this. I have been using redline MTL since I bought my 07 streeglide. I noticed a howling noise coming from my primary for over a year! I thought it was the A.I.M clutch device I installed when I went to a 103. Come to find out I had a bad main shaft bearing! I truly believe that if I was'nt running the mtl, the bearing would have exploded causing major damage and possible rear tire lockup! My thought's are that by running mtl it ran cooler, lubricated better, and being a synthetic, held up much better that convetional oil. I won't use anything else.

Round and Round
 

07ROADHAWG
Used 20-50 for a while and had tons of clunk and didn't really like the feel of the clutch.
Switched to Formula+ and was much better.
Since I can't leave anything alone (and after reading about it here), I then switched to Type-F (pick the brand you like) and am really happy with it thus far. I decided on it over the Dex III due to no friction modifiers in the Type-F, and seeing Type-F recommended by a few different clutch disc manufacturers. No slipping and good feel in slow speed maneuvers. With a good clutch adjustment, I don't get any first gear clunk despite what others say. B&M Trick Shift has been mentioned as well, and the bottle says it is suitable for a transmission that specifies Type-F. Valvoline was 1/2 price of B&M so I used the "less is more" philosophy on it.
I think, like many others, that M1 (or any other high tech synthetic) is probably overkill in the primary. The main function of the oil in there is cooling the clutch pack and providing a little lube to the chain and bearing. So a high tech oil isn't necessary, but does make it simpler just to dump in the same oil as the engine and be done with it I guess.

This seems to go round and round but you sound like you have some experience. I have been running Harley Syn3 in engine,75-90 Synethic in transmission and Formula 1 in primary. Would not mind not hearing less a clunk going in 1st but not really sure why you think Type F would reduce it. I know the 75-90 Syn is thinner then Formula 1 and when I put in in transmission it clunks a tad louder and I had read try 75-140Syn. I ride year round and need an oil to suit 99 degrees to 35 degrees and I was thinking the 140 may cause shift problems in the winter. Is you line of thinking that the type F helps the clutch plates disengage due to oil windage and therefore less clunk shifting into first?

The post that referenced what Mobil techs recommended seems to make sense. Wet clutches in other applications usually recommend 10W40. 10W40 oils typically do not have friction modifiers (like moly). Avoid any oil labeled "energy conserving" as these oils typically do include moly additives and that isn't a friendly mix for clutch plates. I am sure that most of the oils recommended here to include the HD brand do not contain friction modifiers.

It's your money, but any cheap motoroil is just fine as is type F ATF.

I just did my service on mine. Schaffers 7000 racing 20-50 in the engine. Redline in the trans and Mobile 1 atf in the primary. Never going back to anything else.

primary
 

Redline has something that they market as v-twin primary oil. The rest of their stuff works great, so I gave it a try. I could tell a difference in the clutch right away, as it seemed to be more progressive with a better feel. I looked on their site and it said this was basically 70w80 synthetic gear oil repackaged as this stuff. Whatever, but it seems to work fine. The manual says you need 38 oz, so you have to buy 2 qts.

Look in your owners manual. It recommends Formula+ or Syn3 20W50 Oil.
So I would think the Amsoil 20W50 V-twin would be fine for it. I just switched back to Amsoil from Mobil 1 I'm still using Redline Heavy Shockproof in the tranny. Amsoil 20W50 everywhere else. IMO, I think ATF is too light for the primary, Plus if you overheat ATF it ruins it. These engines do get hot!

I just read an article by Joe Minton in the June issue of American Rider about big twin clutches. In it he says that ATF is the best for smooth shifts but worst for your wallet. Clutch wear is not a problem but decreased chain and sprocket life are. He also says gear oil is to thick and causes the plates to stick. So a compromise like Formula + is best in the long run.

That is what I was thinking on the clunk. The lighter ATF (not just Type-F) seems to give better plate separation especially when cold. I'm running Redline Shockproof Heavy in the trans, so that may contribute to the overall smoother shifts.

Yes the engines do get hot, but what does that have to do with the primary fluid? Separate reservoir and all.... Slipping the clutch a ton would get the primary fluid overly hot.

I don't know if the reduced chain and sprocket life is really a concern. Final drive chains and sprockets last many, many miles without being in a constant oil bath. I realize the chain types are different, but I'd just figured that the constant oiling provided in the primary would be more than enough. I guess time will tell.

FWIW, Formula+ is gear oil. I'm not sure of the weight, but that's what it is.

Chain life
 

Chain and sprockets are rather rugged. Mine were over .05 out of line for 10K before I caught it and did not appear to hurt them. As far as ATF type F , My concern is the open running bearing that the transmission shaft runs on when it comes thru back side of inner primary cover. The inner race on most Harleys is the shaft and this has been a problem for some. (not talking about the clutch basket hub bearing)

Yeah, you are right about that. It has been a problem on many bikes. I'm not sure that the primary oil makes a difference on that since it's a roller bearing and it doesn't rely on a cushion of oil for lubrication, just lube for the rollers. Maybe not. I'm pleased with the performance thus far, and if I have to replace the inner primary bearing and race, I'll do it. This is all work I have tools for and can do in the garage. I realize this is a concern for many, but I'm just gonna ride.... :icon_headbang:

Just to further explain my rationalization.... I figure automatic transmissions have electronics, kevlar clutch discs, and bearings. Transfer cases have chains and bearings in them. My car has full time all wheel drive and has ATF in the transfer case with over 100k miles on it. I realize this isn't exactly apples to apples, but it's in the same ball park and I'm just not that concerned about the ATF providing adequate lubrication.

Yes the engines do get hot, but what does that have to do with the primary fluid? Separate reservoir and all.... Slipping the clutch a ton would get the primary fluid overly hot.

The Primary is bolted to the engine. you don't think heat is transmitted through the entire area. Heat will transfer through metal casings and the entire unit get's pretty hot.

Sure there is a little heat transfer, but minimal especially with all the airflow. You think it's enough to burn ATF?

Been a mechanic for the better part of 20 years. I know how much heat atf can take and especially mobil 1 synthetic type f. Also if the engine is getting that hot to were the primary is getting hot enough to burn atf then your engine oil is toast also.

ATF has been used for years in automatic transmissions, manual transmissions and transfercases. If it can properly lube all these then it is more then good enough for the primary, well actually better because of the clutch discs in the primary.

I looked at the formula + fluid. Not very heavy stuff.

I did the Syn3 thing for the first two changes. That stuff is about as good as horse piss in my opinion. My trans clunked baddly. Clutch operation was less then optimum. and once the motor warmed up it had very little pressure and the top end started sounding like a singer sewing machine.

I did the syn 3 it sucks I agree.

This is what RK4ME found
 

Ask Mobilhttp://www.mobiloil.com/USA-English/...bil_image1.jpghttp://www.mobiloil.com/USA-English/...anner1.0_4.gifhttp://www.mobiloil.com/USA-English/...ges/spacer.gifhttp://www.mobiloil.com/USA-English/...ges/spacer.gifATF Choices for a Harley-Davidson FLHT Primary

Ask Your Stickiest Question. . . Or ask us something you’ve always wanted to know about using our products. We’ll sort through all the submissions and present the best questions to our automotive experts. We'll share the questions and their answers here.
http://www.mobiloil.com/USA-English/...anner1.0_5.gifhttp://www.mobiloil.com/USA-English/...ges/spacer.gifQuestion: ATF Choices for a Harley-Davidson FLHT PrimaryI have been told that many Harley owners use Type F (Ford) ATF in their primaries, for one thing to make it easier to find neutral. I have some Mobil 1 Synthetic ATF Multi-Vehicle Formula that I was thinking about putting in my FLHT primary, but the back label states that it's not recommended for Type F applications. I don't want to put it in my primary if it has a lot of friction modifiers in it because I don't want to cause clutch slippage. What are your thoughts on using this ATF in a Harley primary? Thanks.-- Ken Carpenter, Buford,

GAhttp://www.mobiloil.com/USA-English/...ges/spacer.gifAnswer: Although an ATF may work, we suggest shying away from using it due to the low viscosity of ATFs and the possibility of premature chain wear and/or noise. We recommend Mobil 1 Racing 4T 10W-40 for Harley primary transfer cases. Alternatively, one could go with Mobil 1 V-Twin 20W-50.

I've been using this:
Manufacturer's Part #: KH-C80
Klotz V-Twin Primary Case Lubricant Quart


Klotz® American V-Twin Synthetic TechniPlate® Primary Chain Case Lubricant is custom formulated for the Harley Davidson® Big Twin Models. Exceeds all warranty requirements for Harley Davidson® engines. Use of this lubricant provides certified warranty compliance and protection. Penetrates deep into chain rollers to loosen stiff links and extend chain and sprocket life.
Price: $13.60