6026 whistling tender question

[mpzpw3]

Spent the week re-building whistle tenders. All went well except for the 6026. I completely cleaned and re-wired it. When I first apply power,the tender hums, although the whistle button has not been pressed. Upon pressing the whistle button, The relay works, and the motor spins. It screeches terribly! At the moment, it is way over-lubed, which is helping the screeching, but I only get a whistle sound about every 10 seconds, which is just a real short toot. I could sure use some suggestions on this one! So far I'm batting 5 out of 6, and sure could use some help on this one.

[ADCX Rob]

First, make sure the impeller is not physically hitting the housing - the housing or impeller sometimes warps.

Check that the brushes are worn evenly & have planty of material left.

Check the brushplate bearing/bushing for excessive wear, & lube with oil.  Sometimes this bearing is "ovaled"...  a little slop can be dealt with by using grease intstead of oil.

The lower bearing is difficult to reach & lube and it is typically stiffened up over time.  If you can, remove the motor assembly from the chamber & lube the bearing with a needle oiler from the impeller/vane side, as well as from the armature side(going down between/through the windings), with a good lightweight synthetic oil(I use Mobil 1 in a precision oiler). 

Use a break-in procedure to get the oil into the bearing by running the motor while out of the chamber, re-lubing if necessary.

Rob