WR 450 bearing problem
Posted May 04, 2012 - 05:23 AM
I'm currently rebuilding gearbox on my '05 WR 450. I just got all gearbox bearings that i ordered from my local yamaha dealer (Poland). One of ordered bearings is not the same as original one.
Dealer said that this part was replaced by another. I did some research and found out that original bearing (KOYO 6004 SH) can resist 10 times longer in contaminated lubricant compared to standard bearing. All bearings for gearbox have SH mark. SH stand for special heat treatment.
Dealer send me standard KOYO 6004 bearing with C3 internal clearance. I have request, can someone check for me this part number: 93306-00426 and get information if it is really replaced by 93306-00423 ? I think that something is wrong, if i use this standard bearing it can broke very soon.
Apologize for any mistakes in post.
Posted May 04, 2012 - 08:55 AM
get the SH bearing if you want it to last, if your selling it, just build it up as it will run and last, but not as long
The C3 clearance is normally just the crankshaft I believe, the gearbox uses std clearance bearings (but I may be wrong here) - has the original bearings got C3 clearance stamped on them
Posted May 04, 2012 - 01:55 PM
try here - ships worldwide
seems that the 0426 bearing has indeed been replaced by 0423
Thank you for link and information. It is interesting, why they repleaced this bearing? All other bearings that i ordered have this SH mark.
Posted May 05, 2012 - 03:38 AM