Help! Trying to repair Panasonic motor on Raliegh Dover

[Pholcus]

Hi All,
My wife's Raleigh Dover recently starting making a rumbling noise when the motor is in use. I've taken the motor off the bike, split the casing and checked the bearings. Can't find anything obvious, so I want to check the bearing on the motor. So far all I've managed to do is crack the plastic around one of the lugs by tapping it with a small hammer :-(
Anyone got any tips for getting it off without any more damage?
What tools would I need to remove/replace the bearing/s?

The local bike shops including the one we bought it from have been pretty useless, either not wanting to touch it or wanting us to buy a new motor or bike. Surely the motor should last longer than 4 years of normal use. It hasn't been abused at all, my wife has asthma and wouldn't be able to even ride without the electric assistance.
Not sure I would buy an e-bike with a Panasonic motor again.

 

[Wander]

Have a look around flecc's web site pages here.

 

[Pholcus]

Hi, sorry should've mentioned that I've got as far as I have by following Flecc's excellent site.

 

[flecc]

Getting the motor off the crankcase side is often very difficult, I've always managed by using the sharp edge of a screwdriver or chisel to insert between the two with light tapping.

This webpage link gives how to change the bearings, it's usually the small outboard one that goes, due to it taking the end thrust from the helical drive.
.

 

[Pholcus]

Thanks for the reply Flecc. The link didn't work for me. What is the normal life expectancy for one of these motors?

 

[Croxden]

Getting the motor off the crankcase side is often very difficult, I've always managed by using the sharp edge of a screwdriver or chisel to insert between the two with light tapping.

This webpage link gives how to change the bearings, it's usually the small outboard one that goes, due to it taking the end thrust from the helical drive.
.

Link didn't work for me either, not that I need it.

 

[flecc]

Sorry about that error, here's the working link

On the page you go to there's another broken link in the text at one point. Pending my fixing that, here's that second link
.

 

[Pholcus]

Thanks for the help Flecc.
The motor is now off (hammer & chisel worked a treat). The only bearing that I can feel any play in isn't the one on the motor but the small one under the nylon cog. Could this be the cause of the rumbling? Having taken it all to bits I'm thinking of replacing all of them. Would this be worth doing? It surely must be a bearing that's making the noise.

 

[Martin@e-bikeshop]

Hi,

Unfortunately I cannot offer any technical advice on this one, Flecc's website is by far the most informative as mentioned above.

Thanks for the reply Flecc. The link didn't work for me. What is the normal life expectancy for one of these motors?

Normally they are pretty bullet proof to be fair!..

Although we have moved over from Panasonic and now solely support Bosch & Yamaha eBikes. If its some basic spares you are after: I do have a Panasonic 26v motor downstairs somewhere in my spares.

Can't remember the history of it, but it would have been removed as faulty at some point. Probably more electrical than mechanical. I could offer it out at a ridiculous price? Could be stripped of anything thats useful in getting your one back up and running... Be cheaper than sourcing a new unit @£4-500.

If its of interest just drop me a quick email. Flecc will be able to confirm that we have helped out quite a few members of this forum in similar circumstances.

Regards
Martin

 

[flecc]

Indeed, Martin has given valuable help to get other Panasonic equipped bikes back onto the road.

It could easily be that bearing behind the nylon gear wheel causing the noise, I've never known that before but there is always a first time.

However the rear motor bearing won't necessarily have play if it's noisy, so it might be worth replacing that as well while it's apart, since that is the most common cause.

As for life expectancy, most work fine long term and the bikes from 2007/8 are almost all working well. Bikes with their earlier unit are often still working at up to 14 years old without attention, and that's almost unique in the e-bike world.
.

 

[Pholcus]

I've taken out the spiral gear and the rear bearing seems ok. However on looking inside the motor it would appear that there are signs of wear. I'm assuming that the inside would normally be coated with a thin layer of black plastic, but there are 2 sections opposite each other where I can see metal. For this to happen it can only be one of the bearings on the spiral gear allowing the magnets to make contact with this part of the motor. Is this correct?

 

[flecc]

That is normal, the motors I've seen have had some areas of metal showing there. I think the thin plastic coating in parts probably isn't intentional, just a sign of some tolerance when the windings are moulded in.

It seems it's only the nylon gear rear bearing that's defective, does it feel rough to turn?
.

 

[Pholcus]

No it's smooth, maybe I'm imagining the movement. I think the only way to sort this is to change all the bearings, put it back together keeping my fingers crossed. As it is the bike has little value so I've nothing to lose and maybe a fixed e-bike to gain.

 

[flecc]

It's very unlikely you need to change the pedelec shaft bearings, I feel sure only the four supporting the motor and gear shafts could be causing this trouble.
.

 

[Pholcus]

yes I'm in complete agreement there. Now to source a small bearing puller and replacement bearings. Motor factors?

 

[Deleted member 4366]

Are you sure it's not an electrical problem. If you get a faulty hall sensor or MOSFET you also get rough running that feels like a mechanical issue?

 

[Pholcus]

I don't think it's an electrical problem as there is no problem with drive slipping or loss of power.

 

[Pholcus]

Tried 2 motor factors and the largest local bike shop, no joy :-( . They all seem to think the bearings are ok, but hard to tell without a load on them, and none have a puller they feel could get them off without damage. They also think that not all the bearings are standard and my best bet is to Google the numbers on each one. (Other search engines are available;-). I've emailed Martin at e-bike shop as it's beginning to look like his offer is the best option.

 

[flecc]

The bearings are standard, others have changed them from time to time. You need a bearing factor though, motor factors and bike shops won't have them.

If you don't have any listed locally, this Google page gives plenty of options.
.

 

[Pholcus]

Thanks flecc, off for my daily bike ride, will look into it when I get back.