Tips on fixing a Tender Whistle

with fine sandpaper polish the two contact points (bottom left) and the opposite (bottom right)  frame and latch.

Have you cleaned all the axles and center roller wheels on the tender? Also make sure that your transformer works with the whistle on any other tender so as to rule out the transformer.

I just had to replace the old disks or something(diodes?) in my post war ZW along with the roller wheels.

Lee Fritz

What locomotive is paired with the tender? Some locos, particularly the 675 K-4, run at such a low voltage that the whistle does not engage properly.

Clean the frame to bare steel where both trucks pass through the frame. NO OIL! CLEAN wheels, Transformer must have good rectifier disk, or better yet, diode replacement.

Rob

Thanks for all the feedback.  I took everything apart, cleaned, rewired and tested individually.  My test setup uses a 1034 with a 167 since the transformer doesn't have the whistle option.  When I have the tender on the track by itself and hit the whistle button, it seems the whistle relay makes contact and then releases quickly.  I can play around a little and get it to stay engaged long enough to get a whistle sound, but not a good solid whistle.  I tried it with a KW transformer with similar but slightly better results.  

I've repaired a couple other styles of tenders before and had better luck than this one.  Thus, I'm struggling with where the problem is - transformer, 167, tender?

  When I have the tender on the track by itself and hit the whistle button, it seems the whistle relay makes contact and then releases quickly.

That is likely normal behavior. Lionel whistle control circuits need a certain load on the transformer to operate the whistle. Often the tender alone is not a large enough load.

The same is true when using a 167 controller.

Just a suggestion, your test setup is certainly less than optimal, try to pick up a 1033, 1044, or LW for a test bench transformer.
Clarification: This won't fix your whistling tender issue. To get the whistle to operate correctly, you need to add more load, whatever transformer you use as a power source.

Didn't realize I needed a load - I added my 671 to it.  Similar results using the 1034 and 167 on my bench.  I could hear the whistle relay kick in and the whistle motor growl, but not sustained enough to get a true sound.  I will try with my KW later.

All of my transformers have some age - I need to get one for my test bench I know I can trust.

I tried it with my KW transformer.  It worked but appears to have some friction - there is a low growling type sound as it starts up.  It only works at full power.  If I back it down to half throttle, I don't hear the whistle motor at all.  Looks like I need to take it apart again and look for issues in the motor.  It appears the whistle relay is not the source of the issue.

John

Have you cleaned the commutator of the motor and replaced the brushes and springs? 

-Roger

I did - always do that first think.  I cleaned the existing brushes as they were copper.  Any opinion on leaving the original copper brushes versus the newer graphite?  The copper on this unit had little wear and just needed some cleaning.

If you "hot wire" the motor to bypass the relay, how does the whistle sound?

If the armature and impeller are not rubbing on anything there may be a glaze on the fiber brushplate where the top of the armature extends.  This is caused by 'dry' running.  This glaze can stop lube from working.  With a small round file gently 'ruff up' the hole, don't enlarge it.  Also clean the armature shaft where it rubs on the hole.  Oil lube and allow the oil to soak into the brushplate.

This procedure has stopped many a 'growl' for me.

Got it working.  It was a combination of things. The biggest issue with the "growling" was the impeller wasn't pushed on the armature shaft far enough causing it to rub on the outside of the whistle.  I was also fighting ignorance in how things work - really appreciate all the help as I used it all to get it working well.  Thanks again!

thanks for posting fix. I searched, as I was having my first whistle rebuilt attempt. Why would tender whistle by self, and spark as if shorting out when it is on the track with other cars?

perhaps shorting truck/roller pickup? I realised, by searching forum, that polarity makes a difference...

"The more I know, the more I know how LITTLE I know..."

thanks!