Changing Oil Seals - 750

Shajota

Shajota

Hero member
Location
Whitsundays Qld
I have done a search and seems to be some conflicting info, so just thought I'd ask and see what current thoughts are.
Looking to change the Mainshaft, Layshaft and clutch pushrod seals. I see pushrod seal has a spring clip so that should be fine, but are the other 2 safe to change without splitting cases. I realise I will damage the seals taking them out so not keen if it is not wise. (Will obviously need to if I run it and starts leaking ;))
I also note the green book says you can replace the 2 seals on the crankshaft without splitting cases - same question.
Any advice welcome.



 
The seals can be replaced without splitting the cases.  You should however, chamfer the edges of the case bores to be able to insert the seals without shaving off most of the rubber outers!  A sturdy wood-carving knife works fine.

Crankshaft actually has only one seal, on the RH side.  Seal for the timing shaft is a bit fiddly to insert, but is do-able.  Don't forget the seal in the sprag clutch... :D

piet
 
If it's possible - get the motor nice and hot 1st - have everything ready and work fast to replace seals - most important - as Piet says - loose the sharp edge on outer edge of cases - regards - Phil
 
Thanks Gents.
Can't get it hot Phil, have it in to many bits at present.
Just changing them as precaution on recommissioning. Was tempted not to and see how they go but thought I really should do as part of the process.
I will take care and try not to stuff up the new seals.......... 
 
don't change them, see if they leak first

If you do change them to take the sharp edge of the hole, use a de-burring tool, yes there is such a thing, just be a bit more vigorous than you would to simply remove the burr, and I would grease them, but I would use Loctite, to ease them in and then set once located.
cant remember, or find the tube of the Loctite number suitable for rubber/PVC onto alloy, but someone will. And cant find the de-burring tool so as to take a photo,
hopeless of Knockholt CLEM
 
CLEMTOG said:
don't change them, see if they leak first

If you do change them to take the sharp edge of the hole, use a de-burring tool, yes there is such a thing, just be a bit more vigorous than you would to simply remove the burr, and I would grease them, but I would use Loctite, to ease them in and then set once located.
cant remember, or find the tube of the Loctite number suitable for rubber/PVC onto alloy, but someone will. And cant find the de-burring tool so as to take a photo,
hopeless of Knockholt CLEM
Click to expand...
"don't change them, see if they leak first"

On balance that is probably most sensible approach. I am changing all o'rings as I go, Ign Oil seal (as I had Primary cover off)
etc etc so will get bike up and running and see which seals leak and change from there noting all the comments about the sharp edges. Won't take much extra work (and voids the chance of me creating a leak where one wasn't :D)
Thanks
 
You must log in or register to reply here.
Back
Top