Prewar Clockwork Engine - Whistle Questions/Help

Dave, congratulations, you do have a prewar Marx Commodore Vanderbilt with the whistling mechanical motor.  They can be found painted all red - like yours - or red with a black nose.  Yours have the correct pre-war style of whistling motor.  Marx also made whistling Mercury and 933 windups post war, but the mechanism is slightly different. (Edit - just realized you are looking at it for a friend.  Congrats to them; it's a nice engine to have in a collection.)

If everything is fine mechanically - and it sounds like it is - then the likely culprit for the whistle not blowing is air leaks in the whistle chamber.  You can remove the chamber from the motor - there is a machine screw in front of the right front driver, and one on the left side of the motor plate toward the top of the plate.  The chamber should slide out of the motor, and then you can remove the screws to free up the side plate of the whistle chamber.  Marx used some type of sealant that reminds me of the Indian Head Shellac we used to use on engine gaskets when I was a kid.  You can use a modern sealant to seal up the edges of the chamber and then put the plate back in place with the screws.  Apply it sparingly, use just enough to get the job done.  Once the sealant has set up, you can block the air intake on one side and blow gently in the other side... it should whistle.  Reassemble into the motor and see what happens.

Now, there are a lot of mechanics inside a whistler motor.  One surprisingly common problem is that the gearset on the bell stud (a bit of a misnomer, it holds the bell in a non-whistling ratchet motor) occasionally fails.  The big stamped steel gear is swaged on the pinion gear, and for some reason they can loosen up.  The impeller will still spin, but the two gears slip where they are swaged together, and the impeller just doesn't spin fast enough to supply the needed air to blow the whistle.  You can check this by locking the brake (or holding the drivers) and attempting to spin the impeller.  If it continues to move once the lash is out of the gears, look carefully at the gearsets and see if one is spinning while its mate is still.  To fix it right, the entire motor has to come apart.  However, it can usually be addressed without disassembling the motor; it needs to be flushed out with a solvent, allowed to dry, and then repaired with a c-a-r-e-f-u-l application of Loctite with a toothpick at the junction between the stamped steel gear and pinion gear.  Just be careful not to get it in the gear teeth or where the pinion rotates on the bell stud.

Take a look at it, and let us know what you find.

Wonderful and most helpful information James.

Many Thanks for taking the time to explain things in such detail and easy to follow instructions.

I'm going to print this off for my friend.  He has good mechanical aptitudes and this will certainly give him great info to begin the task.

He is not online so I will post back on progress he makes when I have news.

Thanks Again

Dave

Well James....My friend is most happy now.

He followed your instructions and he now has whistle on his clockwork engine.

He asked me to extend his Thanks.

Cheers

Dave

Dave, glad your friend was able to get the whistle repaired.  Always good to know another Marx whistler is back in service, especially a whistling CV!