jay mendoza
Petty Officer 3rd Class
- Joined
- Aug 14, 2009
- Messages
- 81
Dissclaimer:
This proceedure does not follow the factory service manual steps and is in no way meant to superceed it or imply that it is a better method. The techniques described herein are alternative methods when it is not possible to follow the steps in the manual due to the special tools required not being availlable, or when certain dissassembly steps are not possible due to the parts being corroded in place, making removal of other pieces impossible to accomplish following the proceedure in the manual.
We borrowed the prop shaft bearing carrired puller tool from our local OMC dealer and could not get the housing to budge, it was seized in place due to it being run in salt water some 30 years ago before I owned it. This left on our own to try and figure out how to pull and re-install the seals.
One thing we did when resealing the lower unit was to drill a hole in the seals and run a sheet metal screw into both of them; then we were able to use a claw hammer to pull on the head of the screw and extract the seals(2) which are installed back to back on both the prop and drive shafts. A dab of grease was use on the drill bit to catch the metal chips and prevent them from getting in the needle bearings behind the seals. A piece of lightly greased paper towel was also stuffed into the ID of the driveshaft needle bearing to protect it from and metal shavings. A tape flag was place on the drill bit to act as a depth gauge, thereby preventing it from going too deep and damaging the gear case. A flat piece of maple was placed between the gear case and hammer when using it to pry the seals out. The emulsified oil was washed out of the gear case using 24:1 gasoline/oil premix fuel. A large socket was used to seat the driveshaft seals with the drive shaft removed, and the prop shaft seals were carefully seated using a long tapered punch/drift with a 3/16 diameter flat head. There was one seal, an o-ring, on the shift shaft that was not changed, as it was not leaking. This seal is under a pressed in bushing and is normally removed after the prop shaft and gear cluster have come out of the gear case, which we did not do. There is a way to remove this bushing without disassembling the gear case: The shift shaft is removed after unthreading it from the yoke, then a greased 1/4-20 tap is attached to a long extension to thread the inside diameter of the bushing. Now a threaded rod can be screwed into the bushing and used to pull it out of the case so the o-ring underneath it can be replaced, and a new bushing is then pressed in the case using OMC adhesive M or equivalent sealant.
These techniques are outlined here as an alternative to using the special tools as outlined in the OMC service manual as many are not available or practical to purchase for a one time repair, or when the prop shaft bearing housing cannot be removed for complete disassembly.
This proceedure does not follow the factory service manual steps and is in no way meant to superceed it or imply that it is a better method. The techniques described herein are alternative methods when it is not possible to follow the steps in the manual due to the special tools required not being availlable, or when certain dissassembly steps are not possible due to the parts being corroded in place, making removal of other pieces impossible to accomplish following the proceedure in the manual.
We borrowed the prop shaft bearing carrired puller tool from our local OMC dealer and could not get the housing to budge, it was seized in place due to it being run in salt water some 30 years ago before I owned it. This left on our own to try and figure out how to pull and re-install the seals.
One thing we did when resealing the lower unit was to drill a hole in the seals and run a sheet metal screw into both of them; then we were able to use a claw hammer to pull on the head of the screw and extract the seals(2) which are installed back to back on both the prop and drive shafts. A dab of grease was use on the drill bit to catch the metal chips and prevent them from getting in the needle bearings behind the seals. A piece of lightly greased paper towel was also stuffed into the ID of the driveshaft needle bearing to protect it from and metal shavings. A tape flag was place on the drill bit to act as a depth gauge, thereby preventing it from going too deep and damaging the gear case. A flat piece of maple was placed between the gear case and hammer when using it to pry the seals out. The emulsified oil was washed out of the gear case using 24:1 gasoline/oil premix fuel. A large socket was used to seat the driveshaft seals with the drive shaft removed, and the prop shaft seals were carefully seated using a long tapered punch/drift with a 3/16 diameter flat head. There was one seal, an o-ring, on the shift shaft that was not changed, as it was not leaking. This seal is under a pressed in bushing and is normally removed after the prop shaft and gear cluster have come out of the gear case, which we did not do. There is a way to remove this bushing without disassembling the gear case: The shift shaft is removed after unthreading it from the yoke, then a greased 1/4-20 tap is attached to a long extension to thread the inside diameter of the bushing. Now a threaded rod can be screwed into the bushing and used to pull it out of the case so the o-ring underneath it can be replaced, and a new bushing is then pressed in the case using OMC adhesive M or equivalent sealant.
These techniques are outlined here as an alternative to using the special tools as outlined in the OMC service manual as many are not available or practical to purchase for a one time repair, or when the prop shaft bearing housing cannot be removed for complete disassembly.