English French German Italian Portuguese Spanish Swedish


912 Gearbox advice

  • Rotax Rod
  • Rotax Rod's Avatar Topic Author
  • Offline
  • Fresh Boarder
  • Fresh Boarder
2 months 4 days ago #22233 by Rotax Rod
912 Gearbox advice was created by Rotax Rod
Hi All,
I would like to ask those people who regularly service the 912 gearbox, what load on your workshop press do you apply to the gear to check the spring preload. I have in the past done it by feel but suspect that there must be an amount in Pounds, Newtons? I would like to be accurate. Could someone advice.

Please Log in or Create an account to join the conversation.

  • Roger Lee
  • Roger Lee's Avatar
  • Away
  • Platinum Boarder
  • Platinum Boarder
2 months 3 days ago #22238 by Roger Lee
Replied by Roger Lee on topic 912 Gearbox advice
The gearbox friction torque inspection is done on the engine at every annual or 100 hr inspection. What I normally see is 440 in/lbs - 490 in/lbs as the norm.

Warning, this next step is a Heavy Maint. Tech's procedure.
If the box is off you compress the belleville washers until the they bottom out. I have never seen a specific in writing pressure to accomplish this. Be very careful if you have never done this or have no training that you do not over compress everything and crack your gearbox.

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-574-1080 Home (TRY HOME FIRST)
520-349-7056 Cell

Please Log in or Create an account to join the conversation.