700 squeeling

[AUSS1E]

I have a trex 700 that makes a weird squeal or whistle. It is more pronounced with height pitch. Every bearing has been replaced except the one way and it has new motor, helioption swash etc. it is upgraded with slant gears but now 3rd bearing. Could it be the torque from the slant gear on the lower main bearing making the noise? Any other ideas or experiences? Thanks

[gator79]

Sounds like either the motor bearings or the pinion bearing support. How did you install the pinon bearing support?

I keep my pinon bearing support loose while tightening the motor mount. Then I go back and forth tightening the pinon support incrementally until tight.

[HarveyR]

Does it also do it on the bench? Take the main/tail blades of and see if it does it on the bench.... if it does, bingo: Just take things off one after another until you pinpoint it: Take the tail out, take the main mast out, ..... at the end you should find exactly what is squeaking!

[AUSS1E]

Originally Posted by gator79

Sounds like either the motor bearings or the pinion bearing support. How did you install the pinon bearing support?

I keep my pinon bearing support loose while tightening the motor mount. Then I go back and forth tightening the pinon support incrementally until tight.

I do the same as you. Motor is brand new and it did it with the old one too

[gator79]

Hum...I would still pull the pinon bearing support just to make sure it's ok. I've seen them fail fairly quickly.

Every time I've had that squeal, it's been either the pinon bearing or motor bearings. It's possible that the new motor bearing(s) are bad.

Other than that, Harvey has a good suggestion.