450 Installation Of One Way Bearing Shaft

[Hirobo.61]

Hi everyone. Had a bad crash the other day and ruined my autorotation tail drive gear. Just received a new autorotation gear but need some information regarding removal of the one- way bearing shaft from the old hub or if it's easier just exchanging the old hub with the one-way bearing still in place with the new gear. I have the old hub/one-way bearing shaft combo out of the old gear ( no damage to these parts) and they are still together. Is there a way to remove the new gear's hub and install the old combo ( hub and one-way gearing shaft)? If not, how do I exchange the 0ne-way gearing shaft from the old hub to the mounted hub in the new gear? Any videos, articles or just a an explanation would be greatly appreciated. The heli is a trex 450Plus.

 

[murankar]

If I remember, its been like 6 or so years since I worked on an align.

All the metal bits of the one way system fasten into the plastic gearing. Personally if you have all the bits I would replace the entire one way system. Then rebuild the old one for a spare.

 

[Admiral]

When you have the main gear removed, separate the two gears making sure you don't loose the spacer from the top of the main gear, remove the one-way bearing shaft from the old gear and insert it in the new gear, making sure the hole are lined up,(I normally place a small screw driver through the holes to keep them lined up) slide the main gear back onto the 1-way shaft and replace the top spacer. The tricky bit comes next replacing the assembly into the helicopter and getting the hole in the main shaft lined up takes a bit of practice, ( check the main shaft is not bent before starting this) put the gear assembly into place, slide the main shaft in down until it touches the small screwdriver, line the holes up using the top hole in the main shaft as a reference remove the small screwdriver and push the gear into place then insert the bolt through the hole in the gear which should still be lined up. With practice it becomes easy, just take you time the first time .

 

[Hirobo.61]

Thank you Admiral, I used a wooden dowel to press out the one way bearing shaft and pressed it into the new gear hub; lined up the holes and all is good. Main shaft is new so everything fits as it should.
Again, many thanks for your learned advice.

 

[Tony]

A little late to the party lol. Sometimes on these (I know you already have it completed, just sayin') the OWB is pressed into the base with a little green thread locker which is made for slight interference fits or even slightly machined fits of <.001". The green stuff is strong and a little heat will soften it up. Using a wooden dowel was a great idea, much better than metal. The only thing I would do is make sure the bearings inside the OWB don't have a flat spot on them from grabbing really hard onto the sleeve. I doubt they would, but worth it to check. And make sure you use the proper grease on the OWB. Oil, as the manual states, can cause the bearing to slip in some occasions. Some on here will say all they use is oil and it's fine, some will say use only OWB grease. It's kind of like the "which gyro is better" discussion lol. If it works for you, stick with it.

Also, did you replace the sleeve? If not, again check it to see if it has marks from the bearing. If so, toss it and replace it. It will still grab, but it may not let go if there are dimples in the sleeve.

These are picky things that I always look at after a crash. So yes, I have looked at a lot of them hahahaha.