5th GEAR 2009 ROAD KING

[Tony Cross]

Finding my 5th gear sounding like a band saw. It has now done 4500 miles but has not gone quieter. I have added slick 50 gearbox treatment which in the past I have found beneficial but the box is still far too noisey. Has anyone had similar experience or made a formal complaint about this?.

[Urrell]

You probably know this Tony. Copied this from another site (I hear the 6 speed box is all helical now).

"The reason is the type of gears used. 2-3-4-6 are helical gears and 1-5 are spur gears. Helicals are curved and when they mesh the gear tooth rolls up each tooth like rolling up a ramp as opposed to a spur gear where each tooth slaps against its mate. Thus the noise. It would have been nice if MOCO made 5 a helical but must have had a reason. Helicals are more expensive to cut but I would hope that was not the deciding factor given the margin they must make on every bike."

Some boxes sound worse than others. The brand new Road King I took out for a trial was terrible in 1st and 5th. It may be worth taking it back for them to check if it is that bad. They may do something about it instead of the stock "They all do that Sir!".

[banquo]

Originally Posted by Urrell

It would have been nice if MOCO made 5 a helical but must have had a reason.

They did have a technical reason, that I read on some US site a couple of weeks ago. Unfortunately, old age has caught uip, and I can't remember what it was...

[Tony Cross]

I may be mistaken but I think 5th is helical on the 2010 RK.

[Urrell]

Originally Posted by banquo

They did have a technical reason, that I read on some US site a couple of weeks ago. Unfortunately, old age has caught uip, and I can't remember what it was...

Speedo pick up for some reason I think!

[Urrell]

Originally Posted by Tony Cross

I may be mistaken but I think 5th is helical on the 2010 RK.

"Harley’s Big Twins are equipped with the 6-speed Cruise Drive transmission, all of which are now fitted with a helical-cut fifth gear to eliminate annoying gear whine. Gear selection is positive if a bit clunky."

Google "Harley Davidson 6 speed helical 2010" Plenty of reviews.

That may just help your cause Tony as they have changed the parts.

[Tony Cross]

Originally Posted by Urrell

"Harley’s Big Twins are equipped with the 6-speed Cruise Drive transmission, all of which are now fitted with a helical-cut fifth gear to eliminate annoying gear whine. Gear selection is positive if a bit clunky."

Google "Harley Davidson 6 speed helical 2010" Plenty of reviews.

That may just help your cause Tony as they have changed the parts.

That is what I am hoping. It spoils a very fine bike.

[grbrown]

Originally Posted by Urrell

"Harley’s Big Twins are equipped with the 6-speed Cruise Drive transmission, all of which are now fitted with a helical-cut fifth gear to eliminate annoying gear whine. Gear selection is positive if a bit clunky."

This is interesting stuff, as I understood fifth is direct, ie 1:1, which suggests the input and output shafts run at the same speed. So they should not make any noise! But gearboxes were always a mystery - black art. Its at the back of my workshop manual, next to - electrics. Says enough!

[Urrell]

Originally Posted by grbrown

I understood fifth is direct, ie 1:1, which suggests the input and output shafts run at the same speed.

Even running at the same speed one is driving the other, drive coming in on the input and being transferred to the output. I believe straight cut gears are stronger but are not so quiet as helical that slide against each other rather than rattle like old mill machinery But for 2010 if they have a helical 5th I may be tempted. Some nice bikes in Chesterfield yesterday. But only bought clothing for wife and grandchildren

[Maggar]

I don't have this problem on the six speed on my 2008 Street Glide, is that the same gearbox then?