Has anyone experienced this failure mode on the SDS MK4is? We noticed that our drive wheel was binding, and upon further investigation discovered that the 10.25mm ID bearing had ground itself into powder. We are guessing it seized at one point and then ground down.
Is this a fluke one-off or have others seen this? We plan to replace all our bearings as a precaution.
Do you have a guess on the hours before failure on the module?
piggy backing off this, were you using lubricant on your modules? Were you jumping off charge station alot? Doing anything unusual prior to the failure?
Not much. ~2 hours?
It’s a shielded bearing, so we did not additionally lubricate it. And no we didn’t do anything crazy before the failure, just normal driving.
We have 2 seasons on those bearings with no replacements to date. We’ve had to replace the large primary rotation bearing at the beginning of this season, that’s it for maintenance. Well that and the new shafts that were a sorta warranty part. We’ve played hard defense, jumped off the charging station more times than I’m comfortable with, and had zero issues. These modules are really well designed. We do a full parts inspection each year and replace what’s worn, that’s it.
Did you notice any issues after initial assembly? Binding gears? Sticking rotations? You could have received a faulty bearing originally or possibly an assembly issue.
We didn’t notice any assembly issues while disassembling the module.
Perhaps it’s just a faulty bearing, or a lubrication issue (either out of the factory or after use). We flood the 4” X-contact bearing with machine oil but didn’t think to do that with these smaller, shielded bearings.
I guess it’s possible that this bearing is more sensitive to lubrication issues due to the slight thrust load it takes and it’s proximity to carpet dust?
Sometimes you just get a defective bearing. It happens in the real world too.
FRC isn’t the real world? 
/s
But yeah that’s possible. We just like to fully understand all the failures we get, and this was an interesting one. Thanks all who have chimed in so far!
We’ve had a similar experience, while we have not replaced them yet, they are certainly not in good condition. We have run 1 offseason, 2 week 0’s, and 2 regionals on them so far.
I’d love to hear feedback from any teams running the sealed version of the 4" x-contact bearings. So far I’ve had 1 failure reported but often feedback doesn’t make it back to me in-season. 5010 is running a set in the MK4i’s and hasn’t had to do any maintenance so far.
We made the upgrade to the sealed bearings and haven’t had an issue yet. We will be conducting maintenance after our state event but aren’t expecting to find any issues.
254 has had no issues with these bearings, but we have had the large azimuth bearing get gummy/binding, probably from driving fast off bridge or over cable protector.
My suspicion is that the load path from wheel to forks to bearing through tiny overlapping corners is applying big bending loads which deforms the balls and ruins the bearing. The WCP Swerve X with screws clamping the inner race I think is a better load path and may be an improvement the “MK5” could do.
Question: is that the new E-clip version of the intermediate shaft, or the original version (with the countersunk #12 screw)? What does the top of the shaft look like? Any witness marks that would indicate that the shaft (or the screw for the older version) was hitting the steering transfer gear? It’s possible that if the shaft was hitting the steering gear, you may have had some impact side loading on this bearing. I still would not have expected it to destroy the bearing, but it may have contributed to some pitting in the races that might have then led to this…
This is the new e-clip version. The top looks pristine.
We had a similar issue with a bearing under the bevel gear (the one in the triangle piece) failing, that module also had excessive wear on the bevel gears so we assume that the bearing failure caused the excess wear.
We had to replace our larger bearing this season, and have noticed some minor non-impactful dents in the shields of other bearings, but otherwise ours have been solid. We also started using a needle to inject a little bit of bearing oil into the shielded bearings as part of pre-event and pre-tournament maintenance. It may not be absolutely necessary to oil them, but we do notice a difference in responsiveness of the drivetrain afterwards.
This topic was automatically closed 365 days after the last reply. New replies are no longer allowed.
