BBSHD scratched axle

[sysrq]

Does shallow 0.1 mm scratch which doesn't catch on fingernail justifies axle replacement? It's close to the left side below the bright reflection.

Chatgtp says it will polish itself out by skf bearing in this case especially with extreme pressure synthetic grease.

Protective covers or tapes on axles aren't popularised during handling.

 

[Diggs]

I would run with it. It won't hurt anything except maybe slowly get worse. I can't see it would bother the bearing or the seal much at all. In the mean time stop by Aliexpress and get a replacement for $20 so your ready on the next tear-down.

 

[4πr^2]

I don't see anything in the photo which would cause me concern. I really don't see anything on the left and below the reflection. Possibly the photo went in upside down? I do see a tiny scuff slightly ABOVE the reflection on the RIGHT. But again, nothing big.

If this was a forged, mirror polished surface, then yes a scratch might be cause for concern. But as a relatively rough, machined part, it's basically just a series of scratches (called tool marks).

If it bothers you, you could likely take a scotch-brite pad and buff the area smooth.

 

[sysrq]

I don't see anything in the photo which would cause me concern. I really don't see anything on the left and below the reflection. Possibly the photo went in upside down? I do see a tiny scuff slightly ABOVE the reflection on the RIGHT. But again, nothing big.

If this was a forged, mirror polished surface, then yes a scratch might be cause for concern. But as a relatively rough, machined part, it's basically just a series of scratches (called tool marks).

If it bothers you, you could likely take a scotch-brite pad and buff the area smooth.

The small white particles are just dust. Its hard to find the scratch even in person. It's not upside down.
Old needle bearing feels gritty and I can see some metal shavings inside. Despite that axle is smooth overall without reduced diameter due to wear.

 

[Diggs]

Old needle bearing feels gritty and I can see some metal shavings inside.

Then those should be replaced and packed in Mobil 28 or better along with a new seal. If I recall, there are two bearings there. The roller bearing on the shaft and a thrust bearing(?).

 

[sysrq]

Then those should be replaced and packed in Mobil 28 or better along with a new seal. If I recall, there are two bearings there. The roller bearing on the shaft and a thrust bearing(?).

The old seal feels tight around the axle. I have Shell Gadus s5 v100.
Also found metal shavings below the 628 motor axle bearing and some cling film left behind by Bafang factory below the 16001 nylon gear axle bearing (might have caused some axle binding issues seen from the start).

Edit.
No actual metal shavings found in needle bearing.
Ordered the axle along the other soon to be obsolete spare parts for good measure.