Seem to remember reading that the 4203 is a straight drop in for the 2010 it is slightly smaller than the 5203,anybody know if this is correct?
This could be correct for some.........I did the 5203 bearing on 2 different 2010's and the width of the spacer behind the stock bearing was different on both of the sleds by a bit. Enough that when machining the transfer gear to fit the 5203 bearing we had to take off differing amounts of material for each of the two.
Some guys have said that the 4203 was a direct replacement for the stock bearing and spacer.........so just make sure that you measure carefully the stock bearing and spacer on your 2010........and make sure it matches the width of the 4203 bearing. It should be close.
Also.......the difference between these two bearings is that they are both double-row bearings meaning they have two rows of ball bearings inside.........however the 5203 is an "angular contact" bearing and the 4203 is a "straight double-row roller bearing". The 5203 bearing has beveled inner and outer races within it that allow the bearing to take a side load / thrust load on the ends as well as providing load support up and down. I hope that makes sense. The 4203 is a straight roller bearing made to take load up and down but not side-to-side.
There is a 10 page long thread on this subject that goes into great detail......do a search and you will find it. Lots of great information there.
The stock bearing is cheap........but there is a couple different things causing them to go bad. Some of it can be from a thrust load placed on the bearing by the planetary gear set........the other is that on some of the 2010's the tunnel itself was manufactured a bit to narrow on a lot of sleds.
The affect of the tunnel being narrow is that when you go to assemble the diamond drive into the chasis.......the correct length drive shaft pushes the ring-gear/output shaft of the diamond drive too deep into the case. Think of it like this.....you have a drive shaft to length.......and you bolt up the tunnel side of your diamond drive housing to the tunnel.......and to a tunnel that is a bit too narrow. Now you place the ring-gear output shaft ( first piece to go in the diamond drive and attach to the track shaft) well if the tunnel is to narrow and the track shaft and ring-gear output shaft are to their blue-printed nominal length.....well now that ring-gear output shaft is sticking too deep into the diamond drive case. When you put the planetary set in......and then the transfer gear......well that transfer gear bearing now rides in and seats out on the I.D. of the ring-gear output shaft of the diamond drive. When you put the case halves of the diamond drive together on this sled with a tunnel that's too narrow you are now placing one heck of a pre-load on the bearing that rides on the I.D. ( inside diameter ) of that ring-gear output shaft.
This is why the gentleman stated above that the correct way to fix this problem would be to take the track shaft out and trim some off it's length. This would make up for the tunnel being too narrow. The narrow tunnel is why alot of these stock bearings are grenading.............lots of side load. The other way to tackle the problem is to machine the transfer gear for the proper clearence and put the double row angular contact 5203 bearing. Though.......it's not as good a fix as machining the track shaft. Sorry for the novel.......just felt inclined to help. The long thread has much more information and pictures to go along with what I have said here.
Take Care and Happy Sledding!
Dave
