Bafang BBSHD Grinding noise after greasing

Hello all!

I recently hit 1700km on my BBSHD and thought that is was time to apply some Mobil 28 grease.
I eagerly cracked open the secondary recution gear and removed the old grease and applied the Mobil 28 on all of the gears.

When i put the motor back together i got a weird grinding noise. you can see it on the video below.

https://youtu.be/uirboNMKNko
(yes, i know that the motor is on the wrong way. just for filming the noise.)
I cannot seem to see that the pinion gear, nor the big reduction gear has any damages. The clutch is also good.
I have not inspected the nylon gear yet but plan to do so shortly.

For reference the motor did not have any bad sounds before.

Can anyone help me with diagnosing the problem? The weird thing is that the sound was not there before i added the grease.
Really appreciate any answers.

I am using the BBSHD wit the eclipce chain ring from Luna and a 52V 13.5Ah battery from EM3ev.

Drittjippi

Hello again!

Update:
I have now stripped the HD down to parts.

1. Nylon Gear
I noticed that the nylon gear had some black axle grease on it. I do not see any worrying sign of peanutbutter-gear-syndrome. Does the profile look good compared to a new one? I also checked the one way baering with the pinion gear, and it seems to work well!
Nylon gear with black grease: https://imgur.com/a/2UF3oUx
Nylon gear tooth profile: https://imgur.com/a/Zu3cbni
Nylon gear from side: https://imgur.com/a/lgGxS1Y

2. Pinion Gear
This seems also to be fine?
https://imgur.com/a/9W9p3Hb
https://imgur.com/a/LB5aFAm
https://imgur.com/a/5byUktf

3. Internals
All the bearings seems to run smooth, . eaven checked the one under the rotor. THe only plavce where i can feel a tiny lag is on the bearing where the rotor connects behind the nylon gear ( https://imgur.com/a/RtrUyJb )
This is not much, and i belive that this shoult not cause any noice. But how knows.

Here are som pictures of the helix hear from the rotor. Does not seem to have any damages. the scrapes you can see on the picture is ony cosmetic.
https://imgur.com/a/tIsFtR9
https://imgur.com/a/aOMZTLJ

My BBSHD has 100 km on and it makes similar sound when there is no load. When it drives me around or i apply brake, it is allmost silent / no grinding noise. I am not worried in my case.

Try applying brake load on wheel.

ginekolog said:

My BBSHD has 100 km on and it makes similar sound when there is no load. When it drives me around or i apply brake, it is allmost silent / no grinding noise. I am not worried in my case.

Try applying brake load on wheel.

Click to expand...

Hi!

Thank you. i have honestly not thougth of that. i will try this and post a update.

Update:

Put the motor properly back together and it seems, as many has pointed out, that it was not a noise that was present when the system was under load. Took it for a test spin in a lot of snow, and it is silent now.



So for the next person that has this problem, try the motor during load before worrying to much!