I put 1 qt in my trans and primary and every thing is just fine , if I was just sitting in my garage running my bike it might be different but we are bouncing down the road tilting side to side

 

Were talking Primary case or are we talking transmission
The last I looked the Primary took 38 ozs. of Primary fluid &
The 6 spd. Transmission took 1 qt. of Transmission fluid
I wouldn't run either one of those 6 ozs. low on fluid

 

Best to fill it to proper level, you do not want to over fill it.
38 wet means a normal change
45 dry mean if you have opened up the entire primary
I doubt you could even get 45 oz in from the derby cover
here is an old rule of thumb that still holds true with bike straight up primary lube should be about here no lower and not a lot higher
Number 7

 

Maybe the easiest answer for some folks to remember is just pour oil in the primary until it hits the bottom of the clutch basket. When it does that your good to go and you don't have to worry about measuring. And yes, before somebody asks, you will have to use a flashlight to see in there. And no, it does not make any difference what kind of flashlight batteries you use.

 

Opps need to get eye's checked, I am talkin primary, Sorry, 1 quart in trans...

 

Since I'm the new math folks, actually 6oz is 15.789474% of 38oz, which is what we were talking about at the time, I rounded it up....skippy. - Jeez

 

whoops typo 48 when it should be 38-

 

Funny this question would come up in a thread. I regularly do the fluid changes on my StreetGlide and my GF's Deluxe. Both are stock 96 ci motors. I have always followed the manual and put 38 oz of Mobil 1 Syn in the primary on both bikes. A few weeks ago while up touring in Colorado my GF started having a slipping clutch. Fortunately we were headed into Durango and I knew there was a HD dealer there. Lady Luck smiled on us and we were able to get the Deluxe in for service (BIG THANK YOU to Slade at Durango HD!!!!!). The tech confirmed that a simple clutch adjustment would take care of the problem. After a quick lunch we returned to pick up the Deluxe and I inquired if any real issues and wondered why the clutch would suddenly need an adjustment. The tech made the comment that the primary was "a little on the full side" and that he had drained a little out. I told him that I always filled with 38 oz as per the manual. He quickly pointed out the need to only fill to the bottom of the clutch basket and no more. I was a bit perplexed and left not knowing for sure just what to do the next time when servicing both of our bikes. I was going to call my local dealership and ask the top tech there as to what his practice is when filling the primary. After reading here I am still wondering just what IS the best practice.

Was our clutch slippage and subsequent need for adjustment just a fluke and a "they all do it" phenomenon? This has never happened to either bike between service intervals and they both have 40K plus miles. I think I will continue to follow the manual.

 

Yep, i fill mine to the bottom of the clutch basket. i agree, 6 oz is hard to tell. The primary sloshes the oil around the chain and the clutch(and the compensater, etc). i doubt having it too full would affect the clutch operation( using synthetic might but thats a whole other conversation).

 

Synthetic causes slippage in the primary whether you realize it or not. The dyno knows. This was told to me yesterday by my local Harley service manager who told me 1 qt. of fluid is fine in there as well.