TromboneChat

I play a 1970's King 5B and the valve has gotten noisy. If the horn is vertical, the valve is quiet but in playing position it can get klunky. I recently had the horn professionally cleaned and asked the tech to look at the valve. The tech said it needs a new bearing. Conn Selmer sells a bearing for the 4B. Would that be the same size as the 4B? I assume it is since they are both 547 bore. Have emailed Conn-Selmer with no response.

Should be, if your horn is the Model 2105. They use the same valve.

There is no model number on the horn. Did they use those model numbers in the 70's? Regardless it's the same as a 4B but with a larger bell. Thanks.

I would get a 2nd and 3rd opinion on your situation. A traditional rotor has so many ways that it can be adjusted to make it work effectively. The need for ordering a new bearing plate (I am guessing that is the part that the tech is talking about) is actually very rare. The bearing plate can be adjusted in so many ways:

*The lip of the bearing plate can be cut to allow it to go in the casing farther, reducing all lateral play.

*The thicker part can be pushed outward so that it has firmer contact with the inside of the casing. This would solve a “spinning bearing plate” problem.

*The bearings on both sides can be tightened for a perfect fit on either spindle by using a bearing shrink tool.

*If the tech does not have the proper size bearing shrink tool, a lathe can be used (with no spinning) to custom size the bearings with a proper sized collet.

These are just the normal tricks done to make bearings fit properly. There are a few more tricks of the trade as well. Again, I recommend that you get another opinion.

rjrberg79 wrote: Sat Jul 19, 2025 12:31 pm If the horn is vertical, the valve is quiet but in playing position it can get klunky.

Yes, this might suggest asymmetric wear on a bearing plate (and/or non-concentricity from the factory). But if things are loose enough for gravity to be a significant factor, the plate won't be the only issue; it's almost certain that all contact points need some attention, as Brian suggests.

Any thoughts on how to find a tech that can do all that?

rjrberg79 wrote: Sat Jul 19, 2025 12:31 pm I play a 1970's King 5B and the valve has gotten noisy. If the horn is vertical, the valve is quiet but in playing position it can get klunky.

Could be excessive end to end play, a common source of noise. Gravity might hold it against the front bearing when it's vertical, but in playing position the rotor might shift and thunk against the back bearing. Not too difficult to fix and does not require a new bearing plate. I'd be curious to know exactly what the tech's diagnosis is and why it requires a new bearing rather than just repair.

We will need to know where you are located if you are looking for a second opinion from another repair person.

Why are you trying to source parts for the repair tech? Sourcing and purchasing the proper parts is part of repair work.

That said, diagnosing something on a message board with no photos or detailed information isn't really something that typically works well. Rotors can have any number of different issues and are not something you can really diagnose this way.

I would recommend that you take it to a tech that is skilled in refitting vintage valves. Now, did this tech specify a valve bearing, or a linkage bearing?

Also, as others have said, I would let the tech do the part sourcing for a valve refit, should any be needed.

I am located in NW Ohio. I appreciate all the wisdom on this forum and I think if I get the horn to the right person, the problem can be solved. Thanks.

Chuck Ward

https://www.chuckwardbrass.com/

Driving from NW Ohio to NE Ohio can be a long haul……I did it many times when I lived in the Cleveland area. There must be some good technicians in Toledo or Detroit that would be much closer. The technician does not need to be a trombone specialist. Technicians that work on horns do this kind of rotary valve work routinely.

Monroe, MI Kevin Powers - Michigan Musical Instrument Service [email protected] (He might be retired)

New Baltimore, MI Ken Robinson - 248 396-8203

Crazy4Tbone86 wrote: Sat Jul 26, 2025 11:08 am Driving from NW Ohio to NE Ohio can be a long haul……I did it many times when I lived in the Cleveland area. There must be some good technicians in Toledo or Detroit that would be much closer. The technician does not need to be a trombone specialist. Technicians that work on horns do this kind of rotary valve work routinely.

OTOH Chuck Ward actually worked at King, and used the same (or at least very similar) valves on the Benge trombones he designed. No question in my mind he'd make it worth the drive... if HE is not retired

boneagain wrote: Fri Oct 03, 2025 4:19 am OTOH Chuck Ward actually worked at King, and used the same (or at least very similar) valves on the Benge trombones he designed. No question in my mind he'd make it worth the drive... if HE is not retired

Chuck's Website is "No longer available"
I expect that he has indeed retired.

Give Buckeye Brass in Plain City, OH a call.

https://www.buckeyebrassandwinds.com/