coopec
N/A
Well my rudder tube should be 3 in above the designed water line. I put a seal as well but the rudder-stock is a virtual interference fit for about 15 inches.
Leaky lofrans Kobra
- Thread starter GHA
- Start date
Well my rudder tube should be 3 in above the designed water line. I put a seal as well but the rudder-stock is a virtual interference fit for about 15 inches.
rogerthebodger
Well-Known Member
Did you specify a stainless steel spring. If not the spring will rust away in no time.
coopec
N/A
I'm sure I did. (I doubt any sea water would get near it anyway.)
smb
Well-Known Member
It gives you the size in the manual list of parts
313 - Seal - 25x43x9
About £5-6 from somewhere like Simply Bearings.
I replaced mine some time back but its leaking again. There is a degree of lateral movement in the shaft that the seal struggles to keep up with.
Amazed at how clean yours looks. When I first replaced the motor on mine i had to drill around the gap between the motor and the housing (several long 3mm bits were used) to break up the corrosion.
Vowed then to remove and clean the interface anually. Never did so yesterday I stripped the siezed motor, gave up due to internal corrosion and just ordered my third motor from SVB at approx e270.
If i had my time again I'd never fit a motor that hangs unprotected in a damp and fusty chain locker, but as I'm stuck with a 7 inch hole in the foredeck I will keep promising to look after it.
Maybe try some acf50 or something to help protect it, but the damp gets past the seals and rots the innards. My brushes were rusted into their holders.
Steve
313 - Seal - 25x43x9
About £5-6 from somewhere like Simply Bearings.
I replaced mine some time back but its leaking again. There is a degree of lateral movement in the shaft that the seal struggles to keep up with.
Amazed at how clean yours looks. When I first replaced the motor on mine i had to drill around the gap between the motor and the housing (several long 3mm bits were used) to break up the corrosion.
Vowed then to remove and clean the interface anually. Never did so yesterday I stripped the siezed motor, gave up due to internal corrosion and just ordered my third motor from SVB at approx e270.
If i had my time again I'd never fit a motor that hangs unprotected in a damp and fusty chain locker, but as I'm stuck with a 7 inch hole in the foredeck I will keep promising to look after it.
Maybe try some acf50 or something to help protect it, but the damp gets past the seals and rots the innards. My brushes were rusted into their holders.
Steve
coopec
N/A
I'm wondering why you have " a degree of lateral movement"?
I had considerable discussion with the experts when installing the rudder. One guy insisted I had to mount the seal in an articulated flexible shaft to handle movement in the shaft. He pointed out there was no way in the world the seal would be able to handle any lateral movement in the shaft.
But when I pointed out my rudder was skeg mounted AND the top bearing was 15 inches in length he agreed there would be no lateral movement.
Is there any way you can eliminate the lateral movement in the shaft?
rogerthebodger
Well-Known Member
I take it that its the worm shaft the is moving when the motor is disconnected. This i normal as the end that fits into the motor is located by the bering in the motor when the motor shaft is inserted into the hole in the worm.
only the top end of the worm has a bearing to control the lateral movement the bearing at the lower end is onlt a thrust bearing to resist any vertical movement of the worm when operating.
One thing to do is to check the fit of the motor shaft in the hole in the end of the worm. I don't think would ware so if the fit is lose it could only be a manufacturing error or the incorrect motor/ motor shaft
only the top end of the worm has a bearing to control the lateral movement the bearing at the lower end is onlt a thrust bearing to resist any vertical movement of the worm when operating.
One thing to do is to check the fit of the motor shaft in the hole in the end of the worm. I don't think would ware so if the fit is lose it could only be a manufacturing error or the incorrect motor/ motor shaft
smb
Well-Known Member
Good info RS.
I suppose another possiblity is that I failed to sufficiently protect the seal when I slid it over the keyway. Long time ago now but I been known to make such schoolboy errors in my haste and excitement.
I suppose another possiblity is that I failed to sufficiently protect the seal when I slid it over the keyway. Long time ago now but I been known to make such schoolboy errors in my haste and excitement.
GHA
Well-Known Member
All sorted, so if anyone gets here via google and wants to buy an oil seal in Faro, this place seems to have a good selection.
Lofrans kobra part 313 is 25 x 43 x 9.
Vedrol, Vedantes e Rolamentos, Lda.
Lofrans kobra part 313 is 25 x 43 x 9.
Vedrol, Vedantes e Rolamentos, Lda.