According to the Service Manual, the primary on my '04 FXST should be filled with 26 oz. of lube. However, I've heard many riders say 'just put 1 quart in, 32 oz.' So which is better, and why? Thanks.

The transmission has a dipstick, so that one is easier. 24 oz. but I find 22 oz. fills it.

 

Fill the primary til the fluid covers the chain below the clutch. The fluid should just touch the outside clutch plate. However many ounces it takes to do this is exactly what is needed.

 

It takes more than the 26 ozs recommended, just fill until to top of bottom of cover opening

 

With the bike upright and level, you fill the primary with enough fluid to raise the level to the BOTTOM of the Clutch Diaphram Spring....

26-30 oz. is the "Norm".....

Just dumping a quart in is asking for trouble.....

 

If i'm not mistaking my service manual told me to put the primary fluid through the derby cover, is this correct??

 

Derby or Inspection cover.......

6 or 1/2 dozen....

Doesn't matter either way.....

 

But that's what my service manual says to do, in three different sections of the manual. The quote is "Pour 32 ounces (946ml) of Harley-Davidson Primary Chaincase Lubricant through the clutch inspection cover opening...".

The owners manual says to make sure the fluid level "is not higher than the diaphram spring". To me, that means check it to be sure it's not filled too high because all of the old oil didn't drain out before you dumped in a quart.

I'm not doubting SB at all, I put a lot of stock in anyone's years of practical experience over what's written in a book. But it sure can confuse some of us a little bit.

 

You have an RK.... The original query was irt a Softail.....

Different primary castings, different amounts of fluid.....

Touring bikes get 32-38 oz of fluid, as the have a larger primary cavity.....

And NO MATTER WHAT, the fluid is to be at the LEVEL, not Fluid Measurement (oz incriment) specified in the service manual...

 

Y I didn't realize there was a difference in the capacity of the primary, I guess that's why you do this for a living and I don't. Keep all that good info coming, thanks for clearing it up for me. Once again, SHB to the rescue.

 

my touring bike takes 32 oz.