I've talked to HD HQ twice about the rattling issue and this is what I've learned:

(1) The rattle originates from the newly re-engineered compensator. It does not indicate that a problem exists, or at least one that is causing any unusual damage.

(2) There are no plans to change this part in '08, but perhaps in '09, so if you plan on waiting for HD to fix the condition before buying a 96-incher, you may be waiting for two years or more.

(3) Since the oil is thicker when cold and the noise doesn't start on my bike 'til the engine is thoroughly warmed up, I asked about increasing the viscosity of the primary oil to 20w50 and was told it was acceptable in our climate (Louisiana). I was told the Formula+ is around a 10w30 semi-synthetic oil, and although a thicker oil may quieten the noise down a bit, probably won't nix it completely. So, at my 1000-mile checkup (that I'll be doing myself), I'll be using Castrol GTX 20w50 and will test it out. After a while I'll report back on the results.

(4) Asked about ATF or gear oil, I was told "too thick." ATF? I thought ATF was thin, actually. Also, except for Syn3 of course, the MoCo doesn't recommend synthetic in the primary because of the clutches.

So, I'm going to switch to a thicker primary oil and if the noise persists I'll just turn the radio up, as apparently a fix is not around the corner. And as for the whining in 5th gear, on my bike the noise is not loud and it doesn't bother me at all. The rattle is a different story.

 

Keep playing their game,try every oil out there-you are still going to have a noisey built bike.You are still going to have that noisey bike come spring,come next summer.They have told many of us that.They arent going to fix this unless you get off your AZZes and put the fire under theirs.

 

So did you try any of that? I did and it quieted it down quite a bit. The fire under their a$$es didn't do squat. Not yet anyway.

 

If you want the best results, use amsoil or mobil 1, 20-50 motocycle fully syn. oil in primary. Formula + is a straight 50 weight oil with added shear properties, it works as good as any, but the fully syn. will do better hot. Repalce your trans oil with a full syn. 75/90 gear oil, again mobile 1 and amsoil do the best, better than redline heavy shock proof too.

 

My synthetic choice is Royal Purple, but it is very slick and I might try M1 after GTX if necessary. Amsoil is out, as it's too hard to find--and no, I won't do mail order on oil. Amsoil is good oil, but IMO overpriced and does not fare as well as RP in wear-ball tests that I've seen first-hand (i.e., not third-party info based on someone's claim).

Temps in the primary shouldn't be that high, so a good fossil oil should hold its viscosity well over the short term (5k mile change intervals). I did run RP 15w40 in the primary of my '96 RK successfully and without any clutch weirdness. The Moco rep told me Formula+ was around a 10w30, so I'm going to try the heavier GTX first, then move on from there if the results aren't acceptable.

 

LP, what did you use to quieten it down?

 

Amsoil Severe Gear in the Primary and tranny.

lp

 

The 75w90 or 75w140?

 

The 75w90. If I could get away with putting that in the engine I would.. Like it simple ya know. I tried Syn3 in all three holes and you know HD is no longer recommending that. So I aint neither.. Didn't help anyway.

Look, the Amsoil will help a little bit. But don't expect a miracle. I have a few friends that pulled the primary, replaced the auto chain tensioner with a manual and reseat the compensator and had great results.
Something to try ya know.

lp

 

The 75w90 gear oil is the equivalent viscosity of a 10w30, IIRC, so I'm surprised it made a difference. Maybe there's something else in it that mitigates that problem. I think I'm in for a fluid swapping ritual 'til I find one that muffles the rattle, if ever. Or, maybe I'll just get used to the clatter or keep RPM's up.

As for changing to the manual tensioner, since there's no cover to adjust it, you'd have to pull the outer primary cover off. That's a $25-a-pop prospect because of the gasket, not to mention the hassle. But the chain likely won't stretch much after about 10k miles, or at least that's been my experience. What do you mean by "reseat the compensator"?