Couple of questions:
I downloaded a manual I bought off eBay for my '08 FXDWG the other day and it states to fill with 32 ounces of lubricant. Now, I know there are many opinions as to what brand to use. Is this the lubricant choice that some say will help reduce the "clunk" of shifting gears or is it the gear oil choice in the tranny that helps with the dredded clunk?
The manual doesn't say how to check the level also, do you just pour exactly 32 ounces into the hole after you remove the primary cover please?
I used Mobile 1 20W-50 synthetic for the main motor so is this a reasonable choice for the primary also or is ATF better?

 

I'm not sure about Mobil 1 20w-50, but I use Amsoil 20w-50. It doesn't have any friction modifiers in it which means that your clutch won't slip. If you use any oil with friction modifiers your clutch will most likely slip. All i do is pour 32 oz. in primary and be done with it. I wouldn't worry too much about the "clunk" because usually it goes away once the bike is warmed up

 

Take no notice of the weight or volume stated in your manual. Drain the old oil and refill until the level just reaches the bottom of the clutch plates and you're good to go,

As far as oil grades go, use a motorcycle specific oil. Some oils have friction modifiers that could cause your wet Harley clutch to slip. Prob best to use the HD specific oil unless you're prepared to research suitabe oil type / grades. At the moment I've got Rev Tech in mine but I wouldn't be adverse to using a m/cycle grade engine oil in the primary. I'd quote grade numbers at you but I think you use different ratings in the US than we do in the UK

Derv

P.S - never had a clunk prob on my Dyna, maybe I'm just lucky but my G/box is as smooth as silk

 

yeah I just pour in a quart. It won't all go in on the kickstand though so I usually get my wife to hold it up while I put it all in and put the cover back on.

 

I just dump a full quart in there. I leave the derby cover on and go through the inspection plate. As far as what you dump in? You won't have a problem with any conventional 10-40, 20-50 or ATF. Don't use synthetic with modifiers, and along those lines - synthetic won't help anyways...

PS - did you drain the tranny and dump a lube in there vs. the oil that was in there?

 

Yes, I drained the tranny after a good run to warm it up around town. I used the Red Line 75W-140 even though it says not to but it's gear oil so I hope it'll be alright. Thanks for asking!!

 

Redline 75-140? You won't get much better than that...

You should notice a smoother shift & quiter gearbox after these 'upgrades'...

 

Thanks Bassman. I will now put the Mobile 1 20W-50 into the primary. Nobody has answered my question yet as to what makes the clunk when going in gear, that's the primary correct?

 

The clunk is normal. its the big difference between American and foreign bikes.
American (harley davidson) transmissions have always had a little clunk sound to them especially when dropping down into first. this can vary depending on how warmed up the transmission is.
You can reduce it by using quality oil, but you can't change the transmission so the clunk will never go away.

Proper filling of the primary is to only fill up until you can see the oil hit the lip of the clutch. on my 03 this tends to be 2/3rds quart. over filing can cause clutch slipage

Also, when you can't buy harley or vtwin oil you need to buy the heavy weight oil for a diesel engine. 20-50 is diesel oil i believe. I don't know of anyone running it in there stock cars.

hope that answers your question on the "clunk"

 

A technique i've found that works to minimize the "clunk". Both on first start and any cold starts, on a carb bike pull in the clutch and wait about 15-30 seconds ( with the clutch in) then shift into first. On my 05 FXDLI I pull in the clutch, wait a little bit, blip the throttle and when the rpm's drop momentarily that's when I shift into first. The clutch plates tend to stick together when not used for a while, i.e. overnight or 4-5 months.