Alternative to OEM output shaft bearing?

[tzar250]

Hi

I'm part way building up a spare engine and would like to replace the transmission output drive shaft bearing.  The one behind the front sprocket.

I'm looking for a suitable (cheaper), non-OEM replacement bearing from a bearing factors, as I can probably get a few seals I need at the same time.

Simply Bearings list one that seems correct: SKF 62052RSRNR Sealed Snap Ring Deep Groove Ball Bearing 25x52x15mm.  It it is sealed on both sides, so would need the inner seal prising out to match the original set up.

Before I buy - they also list a similar bearing but with C3 clearance.  I can't see any C3 stamps on the original bearing and I can imagine it would get hot enough to need the extra clearance but I thought I would check on the forum first in case anyone had any more knowledge or suggestions.

Cheers

[teezer250]

I can't help you on non-OEM bearings,but when I rebuilt a spare engine with new seals etc I had lying in my shed for 12 years,it did not occur to me to replace ANY engine bearings,crank was ok.
After 1,800 miles the bearing broke and collapsed dumping engine oil all over the rear including the tyre while I was out riding in Wales with my mate.
Luckily I was only travelling about 40mph and managed to stay on and stop with the rear end snaking about,the rear wheel was locked solid.Just before this happened I had been giving it the berries over NSL roads towards Bala.
Pulling the clutch in does nothing in your favour when this happens.
I WAS VERY LUCKY TO NOT END UP DEAD OR IN HOSPITAL.
When I eventually recovered the bike and stripped the engine,you could see the bearing had gouges and RUST on the inner bearing surface of the outer race causing the bearing to break up.
There is no way to see any rust on the inner side of the bearing.

Definitely replace with new on the grounds of safety on ANY engine stood for years in sheds/garages etc.

[Toop]

https://www.boats.net/product/yamaha/93306-20576-00

 

[ybk]

...After 1,800 miles the bearing broke and collapsed dumping engine oil all over the rear including the tyre while I was out riding in Wales with my mate...

Scary story I have been back and forth between doing all the gearbox bearing or not. I'm certainly leaning towards replacement now ! 

Hi

I'm part way building up a spare engine and would like to replace the transmission output drive shaft bearing.  The one behind the front sprocket.

I'm looking for a suitable (cheaper), non-OEM replacement bearing from a bearing factors, as I can probably get a few seals I need at the same time.

Simply Bearings list one that seems correct: SKF 62052RSRNR Sealed Snap Ring Deep Groove Ball Bearing 25x52x15mm.  It it is sealed on both sides, so would need the inner seal prising out to match the original set up.

Before I buy - they also list a similar bearing but with C3 clearance.  I can't see any C3 stamps on the original bearing and I can imagine it would get hot enough to need the extra clearance but I thought I would check on the forum first in case anyone had any more knowledge or suggestions.

Cheers

Have you checked the manuals and part lists? Often they specify bearing codes etc. For example the 1KT parts manual says it's a C3 clearance:

[tzar250]

Thank you for the replies.

It was your original post a while back, teezer250, about the collapsing bearing, that prompted me to want to change the bearing on my transmission. Especially as it is a used assembly bought on Ebay a couple of years back - so no idea about prior use or storage.

That's a good spot ybk.  Looks like it is a C3 after all.  The clutch side bearing is also C3 but is pinned, so not so easy to find a non-OEM replacement from a factor.

As it happens, I do have a Yamaha OEM output bearing already anyway that I was going to save for a different engine rebuild but I think I'll just go ahead and use that for the sake of peace of mind and the £10 or so extra cost.

Thanks again for the input.

[teezer250]

I bought a second hand complete gearbox and took no chances replacing all the bearings including the 1st gear bearing.
These cost me £101 including 10% discount from Webbs of Lincoln.