Bosch Gen4 Seal Service & Grease up

Lithovatis

New Member
Sep 23, 2024
7
4
Kefalonia Island GR
If you can’t get specific pliers then a modified Cir-clip plier(s) will work. That’s what I did. There’s a number of pictures posted here (I have posted also) that could help.

I ground off the small pins and thinned out the tip slightly. You may need to sacrifice a tool, or part of a tool, but it works fine for removing that C-Clip.

Thnx for the reply Stihldog!!!
Will get a circlip plier to the sacrificial grinder and try to workout the tip to maybe get it flat???
 

Bearing Man

Ebike Motor Centre
Patreon
Sep 29, 2018
977
2,336
UK
What don't you like about aluminum based greases?
Unfortunately, there is conflicting information for this out there, some manufacturers say it can and some say it can't. I have seen boat trailers where marine grease has been pumped into the hub bearings and the original lithium grease has run out as oil, causing bearing failure in 3 or 4 months. Therefore, I tend to err on the side of caution.
I don't profess to be an expert on greases, but I do know that mixing them, or using the wrong type of grease for the wrong application, can be devastating.
Anyone just grabbing what they have on the shelf is a big no, no. The most common thing we see is high pressure grease or fancy ceramic or Teflon based greases used in clutch bearings! They obviously slip, but they slip under such extreme pressure that it damages the bearing races by polishing them! Some greases make the bearing slip and grip, which shatters the bearing...
You can see where I am going with this, but what I am really saying is that if you want to use a different grease, do your research to ensure it's compatible with the part you want to grease and the other greases around it.
 

Hattori-Hanzo

Well-known member
Apr 10, 2023
428
568
UK
I picked up some Motorex 2000 grease just to see what it's like.

Damn, this stuff is sticky! I've not used a grease like it, it has an almost silicone feel to it and is hard to wash off.

Anyone using it on these seals? I feel like it would do a good job :unsure:
 

Lithovatis

New Member
Sep 23, 2024
7
4
Kefalonia Island GR
I picked up some Motorex 2000 grease just to see what it's like.

Damn, this stuff is sticky! I've not used a grease like it, it has an almost silicone feel to it and is hard to wash off.

Anyone using it on these seals? I feel like it would do a good job :unsure:
Bearing man said is ideal!!!
To bad the store here in Greece sent me the wrong one yesterday 🤬🤬🤬.
 

Hattori-Hanzo

Well-known member
Apr 10, 2023
428
568
UK
Bearing man said is ideal!!!
To bad the store here in Greece sent me the wrong one yesterday 🤬🤬🤬.

What did they send you? I noticed there is a bike specific one but the only difference I could see is it comes in a smaller pot, has a brush and costs more🤷‍♂️

I got it in a cartridge, I assume it's the same stuff unless anyone know different?
 

Bearing Man

Ebike Motor Centre
Patreon
Sep 29, 2018
977
2,336
UK
What did they send you? I noticed there is a bike specific one but the only difference I could see is it comes in a smaller pot, has a brush and costs more🤷‍♂️

I got it in a cartridge, I assume it's the same stuff unless anyone know different?
Exactly the same stuff (y)
 

RustyMTB

E*POWAH Elite World Champion
Jul 22, 2020
2,880
6,976
UK
Off topic but have you got your hot little hands on a Gen 5 yet, BM? & if so whaddya think?
 

Lithovatis

New Member
Sep 23, 2024
7
4
Kefalonia Island GR
Bearing man said is ideal!!!
To bad the store here in Greece sent me the wrong one yesterday 🤬🤬🤬.

They ship the FETT 176 all purpose grease.....

"We are sorry for the inconvenience but we have only the small container with the brush at the moment.... "

No thanx. They took it b....

Maybe the waterproof Belray I have is good for the seals but won't risk it.
Bearing Man said 2000 is good so I go for it.

I have 7 motors to look after and another 3 in 20 days........

Can't play with chances.
One motor is already to the service because of error

Error to DriveUnit Voltage transformer....
 

raymondo

Member
Jan 17, 2019
69
74
Sussex
just wondering if Bosch might have changed the internals in any way on current Gen 4 motors.
I have had a replacement one fitted to my 2020 whyte e150 and have an eye on trying to make this one last a bit longer as I've had to pay nearly £800 to get it replaced.
 

The EMF

🔱 Aquaman 🔱
Subscriber
Nov 4, 2020
1,294
2,506
South East Northumberland
With that new motor you’ll have a two year warranty. I’m into the first year of warranty on my replacement motor and IF it survives the next year to be out of warranty and still working I’ll take it out and send it off to be fully serviced. New bearings, better seals the lot.
A big IF mind you.
 

RustyMTB

E*POWAH Elite World Champion
Jul 22, 2020
2,880
6,976
UK
All I would add is my original motor is abused summer & winter in the UK, is approaching 5000 miles & came back from a service & upgrade at TEMC after 4k with not very much wrong with it at all. Either I'm very lucky or doing the clean & re grease regularly is a worthwhile exercise.
 

The EMF

🔱 Aquaman 🔱
Subscriber
Nov 4, 2020
1,294
2,506
South East Northumberland
My motor/bike is treated in much the same way and ridden in the most atrocious conditions throughout the year. It gets washed off with a hosepipe then dried off with an old towel, I don’t fanny on. Also it’s transported on a bike carrier. My bike is a Whyte E150-RS 2020 and I still consider it to be new 😆
 

Gareth

Member
Apr 20, 2024
116
144
Ayrshire
They ship the FETT 176 all purpose grease.....



"We are sorry for the inconvenience but we have only the small container with the brush at the moment.... "



No thanx. They took it b....



Maybe the waterproof Belray I have is good for the seals but won't risk it.

Bearing Man said 2000 is good so I go for it.



I have 7 motors to look after and another 3 in 20 days........



Can't play with chances.

One motor is already to the service because of error



Error to DriveUnit Voltage transformer....

If you look at the snap in Stihldog’s post, on the tube of Bosch Grease it tells you what it is and quotes the grease specification.

If you look at page 2 of this thread I try to figure out what the specification codes mean. So you should be able to find greases in your country that suit from figuring out the codes and looking for similar spec greases.

Alternative Grease for servicing the CX seal.

But yes,obviously as Bearing Man says, if you can find some Motorex FETT 2000 or similar that looks much the same as the Bosch stuff. A tub of that should keep you going for many years.
 

raymondo

Member
Jan 17, 2019
69
74
Sussex
cheers for that.
I ride mine in all conditions too and give it a hose off occasionally.
I didn't know about the seal thing until I read it this thread this morning, so shall be doing that regularly.
My crank developed some play and it got water in. This is the 3rd motor swap so keen to find a way of making it last longer!
circa 9000 miles on the bike.
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,682
5,250
Coquitlam, BC
If you look at the snap in Stihldog’s post, on the tube of Bosch Grease it tells you what it is and quotes the grease specification.

If you look at page 2 of this thread I try to figure out what the specification codes mean. So you should be able to find greases in your country that suit from figuring out the codes and looking for similar spec greases.

Alternative Grease for servicing the CX seal.

But yes,obviously as Bearing Man says, if you can find some Motorex FETT 2000 or similar that looks much the same as the Bosch stuff. A tub of that should keep you going for many years.
Yes, I am a prolific Bosch Gen4 abuser.
( I should be in jail).
In the past few years I’ve been using the Bosch bearing kit at least every year. Perhaps it has helped since I have less than 20K km on this motor.

A good skid plate, regular maintenance, sticky grease, soften broken cooling fins, proper cadence, no clunking and a bit of luck. My bike has been a submarine several times. (I won’t post pics of my wet underwear) 🙏

But it’s time for a rebuild. A complete strip-down of the Rail. I sensed, or heard, a slight noise from the motor. It’s time for some TLC.
 

Lithovatis

New Member
Sep 23, 2024
7
4
Kefalonia Island GR
If you look at the snap in Stihldog’s post, on the tube of Bosch Grease it tells you what it is and quotes the grease specification.

If you look at page 2 of this thread I try to figure out what the specification codes mean. So you should be able to find greases in your country that suit from figuring out the codes and looking for similar spec greases.

Alternative Grease for servicing the CX seal.

But yes,obviously as Bearing Man says, if you can find some Motorex FETT 2000 or similar that looks much the same as the Bosch stuff. A tub of that should keep you going for many years.
Got a Motorex 2000 big box few weeks back after BearinMans suggestion (y)(y)(y)(y)(y)(y).
 

RustyMTB

E*POWAH Elite World Champion
Jul 22, 2020
2,880
6,976
UK
My experience is it does disperse relatively quickly, so I can see the desire to use something a bit more viscous but then again, it doesn't disappear. I suspect people think it's gone as soon as it stops being a bright green bead around the crank when it's probably still working. And in any event, I reckon 250ml would be a life times' supply.
 

Adyzakydany

New Member
Aug 24, 2024
13
15
London
Great thread and great input from Rusty and Bearing man, so with the seal maintenance, should we also be packing grease behind the white plastic washer? Once the motor is out of warranty, would of course then look at a rebuild/upgrade.
 

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