Noises KH

[PeterB]

Hello,
because of ongoing reparations from my KH follow question.
The bike creates a grinding noise from 3th shift on
In standing pos. no noise
We expect the transmission, we will replace some parts there, ongoing, but there are nowhere signs from problems how grinding from parts against each other’s....
So I expect maybe problem in the clutch ?
Or can the oilpump create noises ?
Maybe someone has some experiences ?
Thanks
greetings
Peter

[PeterB]

Hello
no ideas ?
On ebay is someone offers a trans and he wrote : ..,,about the well know problems with weak 3 shift.......so this should be known, or !? If it comes from trans.....
greetings
Peter

[thefrenchowl]

Ebay is for selling or buying parts, not to get info on supposedly weak 3rd gears...

What can I say, I don't know your bike!!!

And you don't tell us enough...

Have you opened your engine?

Where's the swarf???

Gears missing teeth???

ETC...

If you are so convinced it's in the gear box, I cant say anything to the contrary...

Patrick

[PeterB]

That’s the pint. Trans is our, no visible damages. No swarfs. Maybe bearing with much space....so we are insecure that it is the trans. But which other possibility ?
The trans works ok, only the noise from 3 shift on is there, but comes the noise from trans ?
Therefore the question if maybe has experience that this grinding noise can come from clutch or oilpump......if we set in the trans and the noise is the same we can start by zero.....

[thefrenchowl]

Speedo drive underneath 1st gear? Loose primary chain???

Other way: reassemble engine, start it and listen to it with a stethoscope or a screwdriver to pin point area of problem...

Have you got a peanut tank on it or the big one? It's been known for K/Sportsters big tanks that are not full and badly fitted to enter in resonance with the engine at certain revs... Then sounds like a concrete mixer, but easy to fix with insulating foam on top tube and better screws with rubber washers...

Patrick

[PeterB]

Thanks
In running idle no noise
Speedo drive is new, but Speedo has still problems
Chain will be checked
Tank is a new point for me...
How said before, start with 3 shift, trans works fine, trans is out and no visible wear ...

[EKHKHK56]

Ideally you want to check noise when it does it. Pin point location of noise source. With huge screwdriver up to ear. Hard to do unless strapped to dyno! Maybe running on secure stand but thats not really the same with no load and dangerous. If it only does it 4th gear than it's most likely something 4th gear related and or speed related. Wish we could hear it! Like Pat said need to pin point source. I had a Datsun 280Z come in the shop for new engine. Turned out Alt bracket broke and vibrated, sounded exactly like a rod knocking at high rpm...Anything that turns on bearings is first suspect. Bearings must be felt and visually inspect Races and Bearings and Clearances when apart. Erik

[jOe]

Check the end play on the main and counter shafts

[hennesse]

Have you got a peanut tank on it or the big one? It's been known for K/Sportsters big tanks that are not full and badly fitted to enter in resonance with the engine at certain revs... Then sounds like a concrete mixer, but easy to fix with insulating foam on top tube and better screws with rubber washers...
Patrick

Patrick,
How often have you seen this? Last fall, as riding season was ending, my KH developed this strange concrete mixer sound. It would start somewhere in the 30-40 mph range, continue at higher speed, lessen or stop at slower speeds. But it varied - I couldn't correlate it to either engine speed or vehicle speed. It did seem to be coming from the big gas tank. I tried gripping it with my knees and one arm, and it seemed to lessen - but not reliably. I just figured there was a vibration in the engine that was causing it. You're suggesting it's the tank itself causing it.

It's almost time for riding weather this spring, so I need to get this figured out. I'm gonna try some foam water pipe insulation on the top tube, and rubber washers. I'll be amazed if that is all the problem is - and quite happy!
Dave

[Ferrous_Head]

A "grinding noise in 3 shift an on"

So, I believe you mean it only happens in 3rd and forth gear.

Does it change, get worse or better, under acceleration or deceleration ?
Is the noise still there if you pull the clutch in while riding in 3rd or 4th ?
Is the cam tower bolt tight ?
I would careful check gear spacing and finger rollers as well as the sliding forks.

If your big tank is "drumming" trying filling it completely up first. Big alloy tanks if not mounted correctly when nearly empty can scare you to death with the noises they can make.