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Primary Oil

191K views 59 replies 32 participants last post by  Kainam 
#1 ·
What weight do I use in the primary chain area? My newly purchased manual does not stae any weights except engine oil. Frustrating as hell............I have been using 75-90 in the tranny.
1999 Wide Glide.
 
#2 ·
You can use the same thing you use in the engine. You can use dino. You can use stuff labeled for the specific purpose. Some guys even use ATF in the primary.

I have used the same Amsoil 20/50 in engine, the primary and transmission since I bought my H-D last year. Some guys will use 10w40 in the primary. I have heard that pouring a $13 bottle of synthetic in the primary is wasteful. I'm not sure about that, but the point is that the conditions that make synthetic beneficial don't exist in the primary.

There's plenty of good reading on oils in this oil forum.
 
#3 ·
10w30, 10w40, 20w50, and even ATF-Dextron-III. As long as the motor oil lacks the "Energy Conserving" logo in the bottom rocker, it's all good.
 
#4 ·
I like Dexron III.

Heavier oils (20w-50, Formula+) will cause more "clunk" when shifting due to increased parasitic drag on the clutch plates.
 
#6 ·
Only 10 bucks... you know the oil companies/MoCo have you right where they want you when you say something like that.

Oddly enough, a quart of el cheapo motor oil will work just as well...
 
#8 ·
Using engine oil in the primary is good but engine oil in the tranny.....people still do that?:laugh
 
#9 ·
Yes they do.

Do you know of any transmissions wearing out from using motor oil in them?:think

Transmissions and engines have shared the same lube for decades in other brand motorcycles.
 
#14 ·
I'll bet you'll get more than three answers here! :)

Since my post above, I just started using 10w40 in the primary. As mentioned, it takes a little of the clunk out of shifting.

I have used Amsoil 20w50, formula+ and Mobile 75w140 in the transmission, and the differences are probably not worth mentioning. I have a bottle of Redline on the shelf for the next change. I expect the same.
 
#16 ·
I made the mistake of switching transmission lube from AMSOIL SEVERE GEAR 75/140 GEAR LUBE to RED LINE HEAVY SHOCK PROOF GEAR OIL . The difference was pronounced clunk when down shifting especially into low gear . Hell , the Amsoil 20w50 engine oil sounded quieter than Red Lines gear lube . Will be going back to Amsoil even if it is harder to find .
 
#17 ·
Tell your indy to stock it. I told mine and he said ok. Now it's in town whenever I need it.
 
#18 ·
My indy stocks Spectro heavy duty gear guard 85w 140 so that's what I've been using in my trans. I was considering the Red Line next change but after Roads results prolly stick with the Spectro or Mobil 1.

Not sure where your getting Harley primary oil for $10 , I recall only paying $6 for a qt unless it's the syn ?
 
#19 ·
The huge deal with 6-speeds are the helical cut gears. First and 5th are straight cut, for strength. On a 5-speed, they're all straight cut.

The slanted, helical cut gears were done to reduce noise, but now add a tremendous side load to the carrier bearings that the 5-speeds never had or even saw.

Now you have 2 loads placed on the same bearing and light motor oil isn't cutting it any more.
 
#20 ·
If you want to run engine oil in your bike's tranny, Go Ahead By All Means, you will however be paying repair bills well before you should. As Dave63 posted, the new 6 speeds are not made to run a regular oil for a very long time and give good service. You can't compare apples and oranges like the old saying goes and that is what you are doing if you are trying to do the same with a Harley that is done with a crotch rocket.
I live in Louisiana where we have 9 months of hot weather and it's not uncommon to have very warm days in the other three. You need at least a 90 wt oil in the tranny for smooth shifting and parts longevity. I choose to use the Amsoil Severe Gear Lube, it's offered in 75W-90, 75W-110 and 75w-140 weights. I also use the Amsoil Motorcycle Octane Booster in my fuel tank. Later Fairshake
 
#21 ·
i tried atf in my primary and found it ran really hot . switched back to moble 1 v-twin
20-50 and like it much better. trans what ever was in there is still in there, but i have some plain ol 75- 140 something like that to try out when ever i feel like draining it.
im lazy now-a-days.. so engine primary moble 1 20-50 for me..
 
#23 ·
Great information.

Very informative thread. I've learned quite a bit and I've been riding Harley Davidson's since I was 15. I'm still torn between running 10w40 or 20w50 in the primary. In fact, it was a web search on this subject that led me here. I just did the 10 k service on my 6 mo old FLHX and went back to 20w50 syn in the primary from the 10w40 syn that went in at 1k service. Guess I'll live with it till the next oil change.
 
#28 ·
That's true 165 is right in the range of 40 weight MOTOR OIL, also in the range of 75-90 weight gear oil, which use a different rating system. What that tells you, is of course as far as viscosity is concerned, 20w50 motor oil 40 weight motor oil and 75-90 gear oil all meet the standard.
 
#36 ·
I used Formula Shell ATF on the label said for use in vehicles serv by DEXRON III /Mercon brands. Did not do so well by me when releasing the clutch got a chatter mostly when hot.

Went back to Mobile I 20-5- full synthetic all appears well. Shell not good to use?

Admittedly it was old new stock but was sealed in bottle.
 
#38 ·
me too, me too....

10-40 4T in mine.

I believe that the thicker oil does an even worse job of seeping into the stock compensator - which ends up contributing to the compensator problems of 96 inch bikes.

I have wondered if ATF would penetrate even better - but haven't tried it yet

(acknowledge this is thread resurrection...)
 
#41 ·
Primary fluid

I've always used ATF in my primary...
1985 Softail... 95,000, same clutch plates
Presently: 2000 Softail... 60,000, same clutch plates
Both m/c's were "Hopped-up" a bit & still no problems
ALSO: From day 1, I'd install the Screaming eagle pressure plate.
------------------------------------------------------------------
FYI:
I run Synthetic 20w-50 motor oil (I like Valvoline), don't waste your money buying "Motorcycle synthetic", run the same oil you'd run in
your Hot-Rod & change it every 2,500 miles.>Always run an oil cooler
--------------------------------------------------------------------
Trans lube: 85w-130 Non-synthetic, keeps your trans well lubed & internal parts don't wear out. I change trans-lube every 5,000 miles.
---------------------------------------------------------------------
Advice from personal experience:
EVO engine >> Replace that plastic gear in the oil pump (If yours has one) install a metal gear.
Twin Cam>> Run a gear drive for your cams, both early & late factory tensioner systems suck!
 
#43 ·
But so thick, it can cause 1st gear finding issues on 6-speeds. Which....already have issues.

I used it in my 5-speed for 2 years. I see no difference between that and standard 84w140 synthetic....other than price.
 
#45 ·
I can't but noticed this.... I keep seeing people repeatedly give advice in getting a manual instead of answer the usual simple questions... while it is good to have these manuals, sometimes people just need a simple answer instead of "go get a manual" reply. Anyways, oddly all the people who give that advice, why in the world are these same people giving different answers than what the manual says.
The "manual" says that ambient temp is under 70 use 20w-50, 70-80 use straight 50w and over 80 to use 60w...
If you are going to preach about using the manual, for god sakes please tell these people what the manual says and not what you have decided is best.... thanks
 
#47 ·
I can't help but notice newbies telling us how to answer questions......it does make me wonder.....
Why are you ranting about the recommendations of motor oil viscosity, in a primary oil thread?

You do know primary oil is different than motor oil....tho motor oil can be used in the primary , I wouldn't recommend using primary oil in the motor.

Many people fail to tell us what geographical area and temperatures they ride in, and because our crystal ball is broken they get a generic answer, or referred to the owners manual which every owner should have. If you don't want to buy a repair manual , that is your choice, I wish you luck.
 
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