42B linkage clank

[timothy42b]

I'm getting a clank noise when I press the trigger, and it doesn't seem to be from the usual suspects.

It clicks before the linkage moves, in the axle/spring of the saddle. The axle screw is tight.

Any ideas?

[pfrancis]

If there is movement on the pivot screw other than the intended rotation there are things that can be improved. Since the pivot screw is headless tightening the screw will only reduce the chance that it backs out in use, it doesn’t clamp anything down.

If it wobbles on the pivot the lever can be swaged to reduce play. If the wobble is happening in the thicker/lever side of the pivot other solutions will likely be necessary - like drilling for a fabricated bushing to take up the slop.

If the lever slides back and forth on the pivot (between the saddle legs/arms) a fitment adjustment of one of both parts may be needed.

[rudytbone]

I'm getting a clank noise when I press the trigger, and it doesn't seem to be from the usual suspects.

It clicks before the linkage moves, in the axle/spring of the saddle. The axle screw is tight.

Any ideas?

What are you defining as "the usual suspects". My 42B was clanking until I changed the bumpers.

[timothy42b]

I'm getting a clank noise when I press the trigger, and it doesn't seem to be from the usual suspects.

It clicks before the linkage moves, in the axle/spring of the saddle. The axle screw is tight.

Any ideas?

What are you defining as "the usual suspects". My 42B was clanking until I changed the bumpers.

Usually it's the ball connection, and just needs to be adjusted. There's a knurled ring set screw and a regular screwdriver adjustment screw. And the bumpers if they're worn enough. But this clank seems to be in the saddle area without the linkage moving.

[Burgerbob]

Worn out saddles is very common.

[Blabberbucket]

If there is movement on the pivot screw other than the intended rotation there are things that can be improved. Since the pivot screw is headless tightening the screw will only reduce the chance that it backs out in use, it doesn’t clamp anything down.

If it wobbles on the pivot the lever can be swaged to reduce play. If the wobble is happening in the thicker/lever side of the pivot other solutions will likely be necessary - like drilling for a fabricated bushing to take up the slop.

If the lever slides back and forth on the pivot (between the saddle legs/arms) a fitment adjustment of one of both parts may be needed.

Just wanted to chime in and and say that, aside from adjusting and lubricating the linkage, this is the most accurate answer you could receive. It is almost never "just replace the bumpers" if your valve is operating loudly.

[timothy42b]

If there is movement on the pivot screw other than the intended rotation there are things that can be improved. Since the pivot screw is headless tightening the screw will only reduce the chance that it backs out in use, it doesn’t clamp anything down.

If it wobbles on the pivot the lever can be swaged to reduce play. If the wobble is happening in the thicker/lever side of the pivot other solutions will likely be necessary - like drilling for a fabricated bushing to take up the slop.

If the lever slides back and forth on the pivot (between the saddle legs/arms) a fitment adjustment of one of both parts may be needed.

Just wanted to chime in and and say that, aside from adjusting and lubricating the linkage, this is the most accurate answer you could receive. It is almost never "just replace the bumpers" if your valve is operating loudly.

The lever won't slide along the axis of the axle but it does wobble enough to make a noise. Hard to see, but is there a washer between lever and spring, and lever and saddle mount? Anyway clearly time for a tech.

[ghmerrill]

The Gb valve on my (cheesy Schiller Chinese) bass has always been an annoyance. It's always been loosey-goosey, causing the cheesy ball joints to be noisy because they're trying to move in three planes at the same time. With the amount of use I'm putting it to now, I'd finally had enough and got an Instrument Innovations "Adjustable Gb Lever Saddle" ($37) for it, and Mike Morse at Tuba Exchange was nice enough to do the replacement and adjust the result. It's marvelous now. Absolutely solid and quiet and a pleasure to play. We couldn't use the Inst. Innov. ball joints because of their (relatively small) size. I noticed when I got it back that Mike had also put a slight bend in the F link, which resulted in a true straight line motion of that action. All of that labor cost me $80. So for around $120 I have an immeasurably better linkage on the horn -- smooth and silent.

Little changes can make huge differences.

[Crazy4Tbone86]

Having a loose cylinder around the pivot screw is a common problem with Bach and many other levers. Not only does it create unnecessary sounds when the lever is used, it makes for inefficient action on the lever. As the OP described.....there is a sound (and obviously some motion in the saddle area) before the linkage starts to move. I have heard this referred to as "loss of motion" but I am sure there are probably other terms used to describe it.

Using swedging (or swaging) tools can reduce the extra play in the parts and make the lever more efficient. As Pete Francis described, the problem is more complicated if the looseness is on the side that does not have the cylinder sticking out.

I want to point out that this is a MUCH BIGGER PROBLEM in water keys! Some water keys are so loose that they wiggle laterally as much as a 1/3 of an inch in each direction. Golly, I wonder why the water keys leak! The nice thing about water keys is that most models have the cylinder extending of both sides of the water key. As long as the cylinder is long enough to fill the area between the two sides of the saddle, the chances of achieving a perfect fit on water keys are much higher!

[timothy42b]

Having a loose cylinder around the pivot screw is a common problem with Bach and many other levers.

Is the usual fix replacing the lever itself, the saddle, or maybe both? The lever is just a parts swap, but the saddle would need to be unsoldered and resoldered.

(and no I won't attempt this one myself)

[pfrancis]

A like for like parts swap will almost definitely be disappointing as quality has not improved over time with most factory parts. I would suggest getting it to your preferred tech and ask if they would feel comfortably installing a bushing/drilling and then sleeving your existing lever. This allows for a snugging up of any (as of yet) unperceived lateral play and also the described wobble.

[Crazy4Tbone86]

A like for like parts swap will almost definitely be disappointing as quality has not improved over time with most factory parts. I would suggest getting it to your preferred tech and ask if they would feel comfortably installing a bushing/drilling and then sleeving your existing lever. This allows for a snugging up of any (as of yet) unperceived lateral play and also the described wobble.

I agree with this. When building or rebuilding trombones, I am rarely pleased with the fit and alignment of any hinge screw parts. I usually custom fit everything so that the parts fit properly and move with no loss of motion.

[boneagain]

Tim,
In my less-than-expert opinion sleeving is a "best bet"... as long as your tech has the appropriate reamr(s)!
You will likely prefer that to swaging (swedging... potaytoe... potahtoe...)
Even if you COULD swage both ends, those would highest stress points for repeat failure. Granted, they would be work hardened a bit. Precision reaming will give a longer bearing surface that is more robust from the start.
Not sure who around Richmond would have such a reamer, though... if Mr. McCracken were still with us I'd give it a go...
Good luck!
Dave

[timothy42b]

Yes. In the back of my mind was your mention that he had retired, and the need to find someone skilled enough.

If that is indeed the diagnosis, it is probably safer and cheaper to have a new saddle and thumb lever. I'm overdue for bumpers so I'll have them look at it and get their opinion.

[boneagain]

Yes. In the back of my mind was your mention that he had retired, and the need to find someone skilled enough.

If that is indeed the diagnosis, it is probably safer and cheaper to have a new saddle and thumb lever. I'm overdue for bumpers so I'll have them look at it and get their opinion.

Is the screw head slopping around in the saddle? If not, then the old saddle is fine.

As for safer/cheaper, I refer back to the previous poster who noted that Bach was never particularly good at making sure the final reamer matched the pins used. I suspect you will be happier longer with the sleeving.

You might try contacting Jeff Hudson in Mechanicsville. I think he just started a business.