as usual another thread topic went astray so I am copying replies

zero-E
The gears are constant mesh. The dogs on the gears ingage them to the shafts. That's where the noise comes from. It may shake the shift forks a little too.
A little slack in the primary chain dampens the blow. Slightly raising the top of the chain when putting it in gear has a dampining effect. It's heavy. Quite a bit of drag from the oil between the clutch plates.

1Canuck
In your opinion what part makes the noise?
Trans main shaft is spinning, shift into 1st and bang (metal to metal sound). I am guessing shifting fork.

ZERO-E
Most of the gear clunk in a Harley is ftom the primary chain being too tight- whatever method is used to tension it. And cold/too thick oil in the primary. Make sure you have enough clutch in there too (pleanty of release) Redline Shockproof works great. I do admit I flush my tyranny with 20-50 every time I change it to flush all particals though. Just call me nuts!! Ride it about 20 miles that way and it still comes out looking like Shockproof

shanneba
If the main shaft is spinning so is the counter shaft since the gears are always engaged.
Stopping all 10 gears (in a five speed) you would get sound from all the clearances in all five sets of gears when they stop plus the sound of the dogs engaging into the first gear set.

 

Wow! And all this time I though it was a design feature of 1st gear engaged indicator!

 

 

No syncros or clutch brake. By the way BMW's don't clunk, or do they? A good trans oil helps the clunk but does not make it go away. It is a million dollar question! Redline light and heavy help, but there is a million answers.

 

Clutch drag due to lack of clutch plate separation(improper adjustment or aftermarket easy-clutch add ons)or wrong primary oil or incorrect primary oil level, or combination of any of these.

 

yep ! clutch plates sticking together is the main cause. try holding your lever in for alittle bit before dropping into gear. it helps to rev the engine alittle to, it breaks the clutchs free.

 

I agree. I've been using 15/40 wt HDEO for the last 5 yrs, and the 1 st gear bang happens only slightly when the temp is below 50, for the 1st shift of the day. After that, it only clicks into gear. I love that stuff.,,,

 

please do not repeat the clutch plates cause the issue etc.

what metal parts make the sound

 

I don't know, Ive adjusted my clutch properly and I never hear a clunk.

 

Looking at the Transmission Power flow diagram in the service manual, it is drawn with the gears used for first as the only straight cut gears. They also are drawn as having a coarser looking tooth structure compared to the other gear sets.

The parts diagram also shows the gears for first as straight cut- numbers 26 and 28.

Sportster transmission gears

Looking at this video ( A four speed) it looks like in neutral just part of the main shaft and the counter shaft spin
The gear set for first spins.