TT Noise + Vibe – what is normal?

[Sean_M]

Hi Fellow Heli-Freaks,

I have a TREX 450 Pro that I crashed and have re-built with an FBL head and BeastX. I am noticing more of that “bearing-rattle” sound that seems to be coming out of the front TT bearing and gear assembly. The noise comes and goes throughout a flight and seems to correspond with minor tail vibration. I am trying to figure out what parts needs replacing.

When I shake my 450 Pro you can hear the TT bearings shake around. If I hold my blades just against the One Way Bearing so that the rear TT gear is locked there is no noise when I shake the Heli.

I have replaced the following:

complete main gear/auto rotation gear OWB assembly
rear TT gears (not the bearings)
the Torq tube (not the TT bearing)

Thanks!

- Sean

[fuzzyllamma]

Check the front torque tube gears u just replaced to make sure there is no burrs or distortions. I have had numerous sets that have little plastic imperfections that rub until they ground off and they will make a hell of a racket while in the air. I have also had bad bearings on the the tt gears that make alot of noise. I replaced them with bocas and have been happy since. I would also check the tt bearing itself to make sure it is secured on the tube and turn the shaft in the bearing to feel for notchiness. Lastly, check the rear tt gears to make sure there are no said imperfections in the gears and check the bearings. Check the shaft from the one rear tt gear that goes to your tail grips to make sure it isnt bent.