Hi all, the left side crankshaft bearing needs replaced on my 3aj. with the camshaft drive sprocket in front of it, how can this bearing be removed? the sprocket looks like its part of the crank and the manual does not show a part number for this bearing. any answers please. thanks T

The gear can be pressed off. The bearing is a standard bearing available from any bearing shop. Make sure to get the C3 variety (= cold play) of the bearing. Should be around 20 Euros apiece.

Auke

thanks auke,

20 Euros? I'll probably want to sell you a lot at that price.

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Fred, XTZ660, Holland.

Dear Freddo,

What does 'probably' mean in this respect? :-)

Auke

me again, what is a C3 bearing? should it be stamped on it or how can i tell? also are both bearings the same size on a 3AJ. thanks again guys T

Auke : means that I'll probably make a lot of profit.
T : C3 is the bearing clearance. Should be marked on the packing.

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Fred, XTZ660, Holland.

freddo: no way freddo
T: yes sir, same size both sides, the winning number is: 6307SH2-9TC4 (uuhm .. the last two digits say C4, which might also be a designation of the play. Check with your bearing shop. or fred?). The numbers are stamped on the outer race, or somewhere at least, of the bearing.

Auke

hi T ,just wanted to give my opion on replacement bearings. Frist off, luckly, I have not needed to replace any bearings in my xt but being a industrial mechanic I know a bit about bearings.
I would recommend getting them from yamaha. sure you will pay more because manufactures often request special features from their bearing makers and they need to make a profit as well. Bearing houses often cannot supply these special features. You may be able to get a replacement that is the same size however it may not be the same bearing.
aukeboss gave the designation 6307SH2-9TC4 breaking it down -6307 is the size -sh is a special heat treatment -c4 notes extra clearnce the 2 and 9 could mean any number of things.

just my 2 cent worth,
winmac

Thanks guys, got both bearings removed today and priced genuine yamaha ones £70. I understand what your saying winmac and i will bear this in mind.i will visit a few local shops and see what they have to say also. thanks again T

Hi all, picked up a set of bearings today. £35 they are identical to the ones yamaha use but half the price! so thanks Mr Aukeboss for saving me some £££s. Now for the REBUILD!!