Bosch performance motor crank movement

mike_s14

Finding my (electric) wheels
Aug 17, 2015
11
2
50
Hi all,
When cleaning the drive train I noticed excessive movement in the motor crank drive, it this a replaceable bearing that can be changed?
Thanks
 

Artstu

Esteemed Pedelecer
Aug 2, 2009
2,420
925
If you have radial play on the drive side crank arm it'll be this bearing that has gone. but double check the size as I'm making an educated guess regarding the size, there are cheaper versions of the bearing also.
How many miles has it done?
 
Last edited:
  • Informative
Reactions: IR772

mike_s14

Finding my (electric) wheels
Aug 17, 2015
11
2
50
Thanks for the reply,
Yes the radial play is excessive.
Wow thats some expensive bearing but I surpose its quite a specialed part.
The bikes a year old now and probably about 500 miles of decent offroad.
Will strip it down and check sizing
 

Artstu

Esteemed Pedelecer
Aug 2, 2009
2,420
925
There's a 2 year warranty on Bosch components, so it should be under guarantee. and 500 miles is nothing at all, I'd expect at the very least 6,000 miles from that bearing for a heavy user.
 

soundwave

Esteemed Pedelecer
May 23, 2015
15,973
6,292

mike_s14

Finding my (electric) wheels
Aug 17, 2015
11
2
50
Unfortunately theres no warranty on mine so will try to repair it myself.
Thanks for the link but can't find the specific bearing.
Are there any special tools required when stripping down the motor?
 

soundwave

Esteemed Pedelecer
May 23, 2015
15,973
6,292
they dont list some parts just email them, ebike shop sells them for 25 quid but there bikes only.
 

soundwave

Esteemed Pedelecer
May 23, 2015
15,973
6,292
 

Artstu

Esteemed Pedelecer
Aug 2, 2009
2,420
925
Unfortunately theres no warranty on mine so will try to repair it myself.
Thanks for the link but can't find the specific bearing.
Are there any special tools required when stripping down the motor?
I'd watch some youtube videos of a motor being stripped first, on the classic Bosch it would be very easy to break the torque sensor if you didn't remove it. I've not stripped the newer motor.

I'm amazed to see the bearing being offered, it's a fair bit wider than the one in the classic motor, and yet I've not seen those offered for sale.

https://www.e-bikeshop.co.uk/eBike-Spare-Parts/Bosch-eBike-Drive-Unit-Bearing
 
  • Like
Reactions: mike_s14

mike_s14

Finding my (electric) wheels
Aug 17, 2015
11
2
50
Thanks for the replies,
Plastic casing off and aluminium cover, the through shaft seems tight.
Seems tobe signs of water ingress from behind the sprocket that hasn't helped
 

Attachments

  • Informative
Reactions: Artstu

soundwave

Esteemed Pedelecer
May 23, 2015
15,973
6,292
  • Like
Reactions: mike_s14

mike_s14

Finding my (electric) wheels
Aug 17, 2015
11
2
50
Cant find a utube guide showing the crank shaft removal and don't want to damage the sensor.
Anybody shed any light as how to get access to the drive bearing?
 
Last edited:

mike_s14

Finding my (electric) wheels
Aug 17, 2015
11
2
50
Doh, I was looking too deep into the casing and what I thought was a seal in the cover plate was actually the bearing.
 
Last edited:

Artstu

Esteemed Pedelecer
Aug 2, 2009
2,420
925
Yeah I can see the bearing but its upto a internal shoulder, but don't know how to split the gearing so I can remove the bearing.
The photo helps as I now know its a two part crank shaft :)
You should be able to prise the bearing off, if that part that comes off the main pedal shaft is like the classic Bosch it will house the motor freewheel.
 

Gigha

Pedelecer
Apr 30, 2015
27
15
72
East Lothian
I replaced the bearing on my motor about 6 months ago so may be able to help.

It is very difficult to tell from the photo you posted, but did the bearing come away with the outer casing or is it still attached to the drive shaft as in the photo below




I actually removed the motor from the bike as it was much easier to work on it at a workbench. From the photo you posted it appears as if there has been some water ingress into the motor. The grease on mine was a nice white colour not the discoloured gunge that is in yours.

The main drive shaft that the bearing is on can just be pulled off, [there are no sensors on it - the photo SW posted has nothing to do with this motor] you though do need to exercise some caution as it is a two part shaft with a Drawn cup roller clutch in the centre section. It does need to be kept very clean or you will have problems down the line.

If the bearing is still on the shaft you will need a bearing puller to get it off, do not attempt to lever it off or you will damage the plastic gear wheel. I had to borrow a yoke type puller as my own puller could not get a grip of the bearing due to the small clearance between the bearing and plastic gear.

If the bearing came away with the outer casing then it will be a simple matter of pressing the bearing out, again be cautious as the casing is very thin and could easily be damaged.

The most difficult part was putting it back together - getting gears meshed correctly required a lot of trial and error.

Note the bearing is an Enduro 6809 LLU Max C3 [6809 LUT fitted originally]
 
  • Informative
Reactions: halfer and Artstu

mike_s14

Finding my (electric) wheels
Aug 17, 2015
11
2
50
Great thanks, the bearing did indeed come away with the casing so I just need to get a large socket and gently push it out.
Where did you get your new bearing from?
 

Artstu

Esteemed Pedelecer
Aug 2, 2009
2,420
925
Great thanks, the bearing did indeed come away with the casing so I just need to get a large socket and gently push it out.
Where did you get your new bearing from?
I did suspect the bearing had spit into two, is that the case?
 

Related Articles

Advertisers