Thank you for making this excellent video. I've been putting off my reduction drive rebuild for a while as there were no warning signs of failure. At 300 hours however, I saw some metal flakes in the oil and knew the time for rebuilding had arrived. Turns out my drive was eating ball bearings like they were PEZ and upon splitting open the drive, the faulty bearing fell completely apart. I found your rebuild video easy to follow and preferable to the approach that the Vittorazi manual describes. I really appreciate your time.
I’ve rebuilt a few Atom80 gearboxes since I made this video. The newer gearboxes are much easier to split the cases making the job much easier. I’ve also found that heating the the bearings will simply fall out by heating the case halves to the correct temp, no need for special tools. But I’d only heat them if you’re planning on replacing the seals too. Check out this video for the update on splitting the cases. Good luck with the rebuild, let me know if you have any questions. th-cam.com/video/Ht8ENpR8htA/w-d-xo.html
@@wednesdaykartingflyingclub8164 Dennis, just took delivery of a new MY20 Parajet Maverick/ Atom 80. I'm a machinist/toolmaker 46 years on now and I do find videos like these extremely valuable. You did it right and it shows folks how not to force things and to be deliberate on their approach to repairing these machines.
@@mikehawkins3263 wow, thanks for the compliment. Trust me when I say that I tried many different techniques on several of the steps. The video only shows what I found worked the best for me. The rebuild and video took me a couple of weeks to complete. I’ve since rebuilt another one in a matter of only a couple of hours. So I really hope that it’ll help save somebody else some time and frustration. Btw, I’m also putting together a rebuild video on the exhaust and top end of the Atom80. Should be out soon. Thanks again for the kind words. I’m just glad that somebody else is interested in what makes these things tic too. 😁 Have fun with your Maverick hope to see you in the sky.
@@wednesdaykartingflyingclub8164 That's great that you want to do more videos on the Atom 80. Exhaust and top end rebuild are two areas that will help both experienced and inexperienced folks tremendously. I'll be watching for them. Thanks again.
Putting those parts in the freezer and heating the cases helps with assembly. The heat expands the cases and cooling shrinks the gears and bearings. It’s not by much, but makes them fit together easier since the tolerances are so close.
Thanks Scott. I put this video together after I rebuilt one for the first time. I’ve rebuilt a few since then and have found a few easier and/or better ways to do it. Just hoping that it helps a few people out in the process. But thanks again for the kind words.
How did you manage to split the case with longer bolts? I'm envisioning that the inside case has threaded holes so the more you tighten those bolts the deeper they go until they bottom out at which point if you continue to tighten it will just tear out the threads so I must be missing something?
@@ajcrm125 the holes in the top cover are threaded to receive a larger bolt than is used to secure it to the bottom case. However, the way used in the video that I originally made does present a real risk of marring up a thread or two of the lower case. Since the making of that video Vittorazi has changed the cases on MY20 and newer models to make it much easier to split them. Also, I no longer use larger bolts to “jack up” a my19 or older one, I use a plate with bolts and washers to “lift the cover up. Check out this updated video. Hopefully it’ll make more sense to you depending on which gearbox that you have. th-cam.com/video/Ht8ENpR8htA/w-d-xo.htmlsi=DsRLNyYlZ4A2i29Q
You’re right, this is without question the simplest way, requiring less tools, to get the job done on a MY18 or MY19 gearbox. This is only one way to get the job done. In fact I’ve used this and one other method where I used a plate to lift the outer case rather than “jack” it up with bolts. (See the video description for a follow up link to this video). Also, the MY20 gearbox does have two threaded holes on the case cover specifically designed to jack it up. Jacking the cover up there would reduce the risk of destroying any threads in the lower case.
Check out Vittorazi’s website for their new maintenance manual. It shows in great detail the breakdown of the gearbox as well using the MY20 or newer gearbox and the two jacking bolts. vittorazi.com/manuali/Maintenance_manual_Atom80_Eng_022.pdf?fbclid=IwAR3Q-giff3-l5xb9oVDGjdLas3HvJzciFITj2-omuz2YC-93aW-U9LPxfHM
I’m pretty sure the socket that I used is 3/4”. However, when pressing bearings, I try to use a socket size that will put the pressure on the outer “race” of the bearing. But obviously it has to also be smaller than the outer diameter of the bearing. The socket that I used has almost a flat surface of the driver side. So it spread out the force on most of the bearing. Yes, any standard grease should work.
How often are new gears required for the rebuild? If the gearbox is getting noisy through high airtime, is it most likely that bearing replacement is all thats required? Thanks!
@@nzmikec in my experience, usually the noise is from worn bearings. I tend to replace all the seals, o-rings and bearings. But inspect the gears and see if the teeth are chipped, polished or have any grooves. Gears are an expensive part of the entire gearbox. So it might not be cost effective to rebuild one if it requires gears, seals and bearings. Best of luck with your decision.
Hi Dennis, great video with a lot of details.. I have a MY20 that needs a rebuild but its a bit beyond my skills,, so do you build for a fee for others??
Thanks for the kind words. I have rebuilt one or two for other pilots. Usually they’re local though to avoid the shipping costs. Are you on Facebook? If so, we could exchange phone numbers and discuss options on getting yours fixed up.
I was going to torque it to 25NM. But it hit 25NM pretty quick and really didn’t seem to be tight yet. So I kept going a little further. It shouldn’t ever come loose though because the rotation of the engine should be tightening it, not trying to loosen it.
@@pascalpeladeau5604 there are a total of four bearing in the case. Two of which are identical and the other two are different sizes. This makes for three different sizes. I took the original bearings to a bearing supplier who determined the sizes for me and recommended that I use the Nachi brand to replace them with. I hope that answers your question.
Vittorazi lubes the gearbox with 30cc of their specific blend of oil. I leave the grease that comes with the bearings on them. But it washes out after the first fluid change anyway and is lubricated by the gearbox oil.
@@snakevera the bolts that I used are 6mm x 30mm long. They thread into the outer case and push down onto inner case. The case bolts are 5mm. So you have to be cautious not to force the bigger 6mm bolts into the 5mm threaded inner case. Keep in mind that there are several ways to split the case. The way shown here is just one. After this video, I’ve found a few better ways to get this job done. Especially in splitting the case. Doing it this way is effective, but does bugger up the original bolt holes slightly.
@@snakevera I made a metal plate that I drilled 6 holes into. The holes line up with the 6 case bolt holes. I then set the plate on the prop output shaft and put (6) 6mm bolts into the threads on the outer case. These bolts need to be long enough to thread into the outer case, but not too long causing them to hit the inner case. Then the outer cover can be pulled away from the inner case. I also learned that the bearings will simply fall out of the cases if heated to the correct temperature (no tools required) and a new one can be put in at the same time if the new bearings are already in the freezer.
Thank you for making this excellent video. I've been putting off my reduction drive rebuild for a while as there were no warning signs of failure. At 300 hours however, I saw some metal flakes in the oil and knew the time for rebuilding had arrived. Turns out my drive was eating ball bearings like they were PEZ and upon splitting open the drive, the faulty bearing fell completely apart. I found your rebuild video easy to follow and preferable to the approach that the Vittorazi manual describes. I really appreciate your time.
Thanks for the kind words. Glad that you found it helpful. I do have a playlist on my channel with other atom80 repair videos.
Amazing. So helpful and very nicely done! Thank you.
Thanks for the kind comment Doug.
Thank you ! I'll rewatch while I'm rebuilding mine.
I’ve rebuilt a few Atom80 gearboxes since I made this video. The newer gearboxes are much easier to split the cases making the job much easier. I’ve also found that heating the the bearings will simply fall out by heating the case halves to the correct temp, no need for special tools. But I’d only heat them if you’re planning on replacing the seals too.
Check out this video for the update on splitting the cases. Good luck with the rebuild, let me know if you have any questions.
th-cam.com/video/Ht8ENpR8htA/w-d-xo.html
Very well done video Dennis. My guess is I will be doing this at some point.
Very informative with lots of detail. Well done. Thank you.
Thanks. Hopefully it helps you if you ever need to rebuild one.
@@wednesdaykartingflyingclub8164 Dennis, just took delivery of a new MY20 Parajet Maverick/ Atom 80. I'm a machinist/toolmaker 46 years on now and I do find videos like these extremely valuable. You did it right and it shows folks how not to force things and to be deliberate on their approach to repairing these machines.
@@mikehawkins3263 wow, thanks for the compliment. Trust me when I say that I tried many different techniques on several of the steps. The video only shows what I found worked the best for me. The rebuild and video took me a couple of weeks to complete. I’ve since rebuilt another one in a matter of only a couple of hours. So I really hope that it’ll help save somebody else some time and frustration.
Btw, I’m also putting together a rebuild video on the exhaust and top end of the Atom80. Should be out soon.
Thanks again for the kind words. I’m just glad that somebody else is interested in what makes these things tic too. 😁 Have fun with your Maverick hope to see you in the sky.
@@wednesdaykartingflyingclub8164 That's great that you want to do more videos on the Atom 80. Exhaust and top end rebuild are two areas that will help both experienced and inexperienced folks tremendously. I'll be watching for them. Thanks again.
Superb video, thank you! Question: I'm curious as to why you put the gear and bearings in the freezer?
Putting those parts in the freezer and heating the cases helps with assembly. The heat expands the cases and cooling shrinks the gears and bearings. It’s not by much, but makes them fit together easier since the tolerances are so close.
@@wednesdaykartingflyingclub8164 that makes sense. I'm always learning something new. Thanks for contributing!
@@WillFly it called Interference fit.
Very impressive. You have skills. 👍
Thanks Scott. I put this video together after I rebuilt one for the first time. I’ve rebuilt a few since then and have found a few easier and/or better ways to do it. Just hoping that it helps a few people out in the process. But thanks again for the kind words.
How did you manage to split the case with longer bolts? I'm envisioning that the inside case has threaded holes so the more you tighten those bolts the deeper they go until they bottom out at which point if you continue to tighten it will just tear out the threads so I must be missing something?
@@ajcrm125 the holes in the top cover are threaded to receive a larger bolt than is used to secure it to the bottom case.
However, the way used in the video that I originally made does present a real risk of marring up a thread or two of the lower case. Since the making of that video Vittorazi has changed the cases on MY20 and newer models to make it much easier to split them. Also, I no longer use larger bolts to “jack up” a my19 or older one, I use a plate with bolts and washers to “lift the cover up.
Check out this updated video. Hopefully it’ll make more sense to you depending on which gearbox that you have.
th-cam.com/video/Ht8ENpR8htA/w-d-xo.htmlsi=DsRLNyYlZ4A2i29Q
How did you split the case using those bolts without stripping the internal threads? Once the bolts bottomed out etc.
You’re right, this is without question the simplest way, requiring less tools, to get the job done on a MY18 or MY19 gearbox. This is only one way to get the job done. In fact I’ve used this and one other method where I used a plate to lift the outer case rather than “jack” it up with bolts. (See the video description for a follow up link to this video). Also, the MY20 gearbox does have two threaded holes on the case cover specifically designed to jack it up. Jacking the cover up there would reduce the risk of destroying any threads in the lower case.
Check out Vittorazi’s website for their new maintenance manual. It shows in great detail the breakdown of the gearbox as well using the MY20 or newer gearbox and the two jacking bolts. vittorazi.com/manuali/Maintenance_manual_Atom80_Eng_022.pdf?fbclid=IwAR3Q-giff3-l5xb9oVDGjdLas3HvJzciFITj2-omuz2YC-93aW-U9LPxfHM
What size sockets did you use to press in the bearings? Is that generic bearing grease you apply at 15:09?
I’m pretty sure the socket that I used is 3/4”. However, when pressing bearings, I try to use a socket size that will put the pressure on the outer “race” of the bearing. But obviously it has to also be smaller than the outer diameter of the bearing. The socket that I used has almost a flat surface of the driver side. So it spread out the force on most of the bearing.
Yes, any standard grease should work.
How often are new gears required for the rebuild? If the gearbox is getting noisy through high airtime, is it most likely that bearing replacement is all thats required? Thanks!
@@nzmikec in my experience, usually the noise is from worn bearings. I tend to replace all the seals, o-rings and bearings. But inspect the gears and see if the teeth are chipped, polished or have any grooves. Gears are an expensive part of the entire gearbox. So it might not be cost effective to rebuild one if it requires gears, seals and bearings. Best of luck with your decision.
@@wednesdaykartingflyingclub8164 Great news, ill keep my fingers crossed! Thanks so much!
Hi Dennis, great video with a lot of details.. I have a MY20 that needs a rebuild but its a bit beyond my skills,, so do you build for a fee for others??
Thanks for the kind words. I have rebuilt one or two for other pilots. Usually they’re local though to avoid the shipping costs. Are you on Facebook? If so, we could exchange phone numbers and discuss options on getting yours fixed up.
What did you torque the clutch bell to @ 16:09
I was going to torque it to 25NM. But it hit 25NM pretty quick and really didn’t seem to be tight yet. So I kept going a little further. It shouldn’t ever come loose though because the rotation of the engine should be tightening it, not trying to loosen it.
Where’d you get the pulley tool?
@@justincohee2875 I bought mine at skysportsusa.net/acc101-multifunction-puller-vittorazi/
Skysports Usa, using Vittorazzi diagrams, calls for a 6200 series bearing. You have a 6202. Which one is right?
@@pascalpeladeau5604 there are a total of four bearing in the case. Two of which are identical and the other two are different sizes. This makes for three different sizes. I took the original bearings to a bearing supplier who determined the sizes for me and recommended that I use the Nachi brand to replace them with. I hope that answers your question.
Did you use any specific grease for packing the bearings?
Vittorazi lubes the gearbox with 30cc of their specific blend of oil. I leave the grease that comes with the bearings on them. But it washes out after the first fluid change anyway and is lubricated by the gearbox oil.
Hey thanks! And is splitting the case really as easy as getting 6 longer bolts same thread and evenly torqueing them? Great video!
@@snakevera the bolts that I used are 6mm x 30mm long. They thread into the outer case and push down onto inner case. The case bolts are 5mm. So you have to be cautious not to force the bigger 6mm bolts into the 5mm threaded inner case. Keep in mind that there are several ways to split the case. The way shown here is just one. After this video, I’ve found a few better ways to get this job done. Especially in splitting the case. Doing it this way is effective, but does bugger up the original bolt holes slightly.
What would be one of the better ways you found as an alternative?
@@snakevera I made a metal plate that I drilled 6 holes into. The holes line up with the 6 case bolt holes. I then set the plate on the prop output shaft and put (6) 6mm bolts into the threads on the outer case. These bolts need to be long enough to thread into the outer case, but not too long causing them to hit the inner case. Then the outer cover can be pulled away from the inner case.
I also learned that the bearings will simply fall out of the cases if heated to the correct temperature (no tools required) and a new one can be put in at the same time if the new bearings are already in the freezer.