crank shaft bearing

[kennystag]

Hi all,
How to you check if the crank shaft bearing is gone, the one that goes into the casing.
Cheers
Kenny

[Donnie]

I presume you mean the drive side bearing ?

[Knowledge]

Is the engine still in one piece? If not, what state of deconstruction are you currently in? Is the crank in or out?

Martin

[kennystag]

Thanks for the replies. Yes the engine is still in the bike. I read some ware about taken out the gear oil drain plug, and checking for back pressure,is this correct.
Cheers
Kenny

[rossclark]

You'll only get pressure if the seal is gone. Won't tell you anything about the bearing.

I don't think there's a good way to check this bearing without at least partial dismantling, if you take the chain case of you could try seeing if there's any lift in the front sprocket.

Other than that you could try listening for a rumble in that area using a large screwdriver up against the casing as a sort stethoscope. With the engine turning that might be a bit tricky to isolate ...

[Captain Pugwash]

Hi all,
How to you check if the crank shaft bearing is gone, the one that goes into the casing.
Cheers
Kenny

PM sent

[kennystag]

Sorry chaps,
I meant how to check the drive bearing seal.
Kenny

[kennystag]

Hi all,
I found what I was looking for.
Kenny
How to check if your drive side oil seal has blown
Start scooter, let it warm and idle nicely. Drain the oil while the scooter is ticking over, preferably into a suitable container so you can re use it. If as the oil is about drained your engine revs rise, your seal has gone.

[Knowledge]

Hmmm. That sounds a bit drastic.

The best evidence that the drive side oil seal had blown is huge plumes of white smoke out of the exhaust, and a very oily plug. This assumes that there is oil in the gearbox in the first place.

If you are planning to replace your oil seals and you intend to fit Viton oil seals, buy from a reputable dealer, as a manufacturer is entitled to call their product "Viton" if they have as alittle as 2% Viton content. You need 30% Viton content for it to be an effective seal. See the next Jetset Oily Rag article.