Gearbox wear: Mobile 1 vs Aeroshell

[jrtens]

This is an interesting discussion for sure but the larger issue seems to be lack of proper lubrication rather than type of oil.

Apparently the gearbox problems were pervasive enough that Rotax decided to modify the gearbox by adding an oil spray nozzle about two years ago.

So now the question is - did that solve the problem?

I guess we won't know until enough owners with the new gearbox (sn 74000 and higher) get to several hundred hours of flying time.

[NinerBikes]

Originally Posted by jrtens

This is an interesting discussion for sure but the larger issue seems to be lack of proper lubrication rather than type of oil.

Apparently the gearbox problems were pervasive enough that Rotax decided to modify the gearbox by adding an oil spray nozzle about two years ago.

So now the question is - did that solve the problem?

I guess we won't know until enough owners with the new gearbox (sn 74000 and higher) get to several hundred hours of flying time.

I thought that was a 912 iS gearbox change.... has it also been incorporated into the 912 ULS? How is the gearbox fed oil, and is there a return line now, too?

[jrtens]

Originally Posted by NinerBikes

I thought that was a 912 iS gearbox change.... has it also been incorporated into the 912 ULS?

Yes - see the latest IPC revision.

[NinerBikes]

Originally Posted by jrtens

Yes - see the latest IPC revision.

Sorry not good with Rotax accronyms. What does IPC stand for?

[jrtens]

Illustrated Parts Catalog.

https://www.rotax-owner.com/en/suppo...series-engines

[NinerBikes]

Originally Posted by jrtens

Illustrated Parts Catalog.

https://www.rotax-owner.com/en/suppo...series-engines

Do you work on these gearboxes regularly?

Seems far too much to know about them with all the iterations, unless you are in the business of repair, and do this stuff regularly?

[jrtens]

No, I just read a lot.

[rv3flier]

I wonder if an existing gear box housing can be retrofitted with the spray nozzle or if there's no existing oil gallery to feed the nozzle in the legacy gear box housing.

[Cammie Patch]

Yes the -12s are running pretty well. We have put about 1000 hours on them in the last 1.5 years or so. The magnetic plugs are very clean.

One of them has apparently vapor locked on the take off roll a few times, and i am attributing that to a winter blend fuel. We use a non-ethanol 91 oct fuel, and even though the supplier swears there is no difference throughout the year, we had problems in the spring, which went away when we began mixing about 10%-20% avgas in.
The other one has a periodic drop in oil pressure that remained when the probes were swapped between planes. No other indications show a problem, and I am replacing the oil regulator spring and ball bearing (to the mushroom style).

Students love these planes. I do too, but I'm tired of all the SBs!
We also have a C172 and a Piper Archer on the line, I much prefer the maintenance on the RVs.

I would eliminate the carbs in a heartbeat if I could.

[Piper J3]

Can you elaborate on replacing the oil regulator spring and ball bearing (to the mushroom style). Is mushroom style an improvement? First I'm hearing about this. Do you have P/N's?