bgreen: question about DD bearing failure

I have seen Diamond Drives with the 6203 bearing that have many miles on them, well over 5000.

If the reason the 6203 is failing is because of some narrow tunnels that are putting side load on the bearing why don't we just put a smaller/narrower shim in behind the bearing? That would relieve any side load.

Would be a lot eaier than machining the transfer gear and track shaft

gonna jump in here, some tunnels are so narrow that it pushes the ring gear into the planetary gear holder. i bet most of you that have had the bearing fail have rub marks on the planetary holder from the ring gear.

it is a valid point oldcrow, if the ringgear/planetary is not rubbing, to go that route though. might be worth a shot??!!

The planetary floats between two snap rings and does not come in contact with the 6203
To get more clearance between the ring gear and planetary you would have to remove material from the bearing stop on the right side of the track shaft

If the tunnel is too narrow the ring gear/output shaft pushes against the planetary which pushes against the snap ring. Not all side load is being put on the 6203,

I believe a smaller/narrower shim would solve this issue

right...but you still don't want the ring gear rubbing on the planetary. bearing would probably hold up better i agree with that.

but while your at the hassle why not just machine down the transfer gear and make room for the 5203???

it basically comes down to either your tunnel is narrow(machine trackshaft or shim out brake caliper), dd case is machined narrow(6203 brg with smaller spacer as oldcrow said or machine transfer gear to make room for the 5203), or a combination of both problems.

Each sled is going to be different, you will have to figure out where the problem lies and go from there, it seems as if there is not a simple fix for everyones problems.

If you are going to customize, i don't see why you wouldn't upgrade to the wider bearing. that bearing is turning at huge speeds ( transfer gear going backwards, and the race seated in the ring gear on track shaft turning forwards) so beef it up as much as you can.

How much do you need to cut off? If you cut too much you could easily end up effectively pushing the output shaft/ring gear out of its lip seal. You could also end up loosing proper gear mesh (axially).


How many of these failures have a witness mark on the piece that holds the planetary, such as the one below? The one pictured indicates an angular misalignment. The axial loading caused by the narrow tunnel is only a piece of the puzzle, albeit the biggest piece.

I wanted to run the heavier bearing and wanted to keep the gear in the same location as found, and I don't want to cut any more off the transfer gear than I have to. As I said in one of my posts in the other thread, we don't have a rigid chassis, there is some flex, misalignment, etc, its just a part of life. Because of this, I want the best, or at least a better, bearing on the transfer gear. Especially the the transfer gears in the 09 and up cases that use the short shaft as opposed to the older 07 and 08 cases that use a longer shaft. (The longer the shaft, the closer the bearing is to the track shaft, the less angular misalignment, the less load on the bearing)

oldcrow said:

To get more clearance between the ring gear and planetary you would have to remove material from the bearing stop on the right side of the track shaft

Click to expand...

I'm sorry but I think this is wrong. You can machine the port side of the trackshaft, the shoulder on the starboard side of the track shaft, space the DD or brake housing away from the tunnel, or cut the outboard shoulder of the ring gear.

oldcrow said:

If the tunnel is too narrow the ring gear/output shaft pushes against the planetary which pushes against the snap ring. Not all side load is being put on the 6203,

Click to expand...

Only if there is enough clearance in the assembly to allow it to get that far, or if the pressure on the cover is so great that the cover deflects that far. The load is on the ring gear, which loads the transfer gear/6203 bearing, which bears against the cover.