MG4 Reduction Gearbox Oil Leak

Colsky I take it you previously had the leak, curious what kind of driving do you do?
Slow speeds small distances or longer drives quicker roads?
Curious as I remember a member mentioning that the leak could be brought about by longer faster drives and an obvious build up of pressure.
If people's drives were shorter and slower then this might not occur hence why it's not happened to everyone. Could be the reason it's still happening, although it shouldn't be.
The car showed the leak at dealer PDI, so they ordered and fitted the new breather before I'd even driven the car.

I haven't changed my driving patterns and haven't done any long journeys for a few weeks. Its mainly short distances with slow speeds, and a couple of 20 mile, mostly 70mph, return journeys a week.
 
The car showed the leak at dealer PDI, so they ordered and fitted the new breather before I'd even driven the car.

I haven't changed my driving patterns and haven't done any long journeys for a few weeks. Its mainly short distances with slow speeds, and a couple of 20 mile, mostly 70mph, return journeys a week.
Cheers, I wonder if that is enough to cause the pressure to build up to the extent the member talked about, wish I could remember who it was!
To be fair it shouldn't matter how you drive it, oil shouldn't be leaking out. That's 3 recent reports of leaks with the new breather the reason why will be very interesting to hear
 
Per garage, MG assistance have to recover car to them as not safe to drive.
Update - AA man has been. Says it has a little oil leakage, not a lot, but agrees with the advice not to drive. He has booked a recovery tow to the garage in the morning. I said I wasn't sure that you could tow electric cars. He said it would be rear lifted, which would be fine as the car is a rear wheel drive. The manual says this, which I assume backs up what he says:

DO NOT tow the vehicle with any of the driving wheels in contact with the road surface, this will avoid electric drive transmission damage.

I'm still not sure that I am happy with this, as the dealer is 30 minutes drive away. Does anyone with more knowledge and experience than me know if its fine to tow an MG4?!
 
Last edited:
Yes with the driving wheels off the ground and not turning the motor it is fine. The problem with a normal ground tow is that even in N the motor is not disconnected from the drive wheels which could cause damage. With it rear lifted and steering locked all should be fine as the drive wheels are not active and front wheels should be free spinning. I suspect car could even be driven with no damage to be honest but the dealership probably wants to err on the side of caution. Also if you can't trust the AA expertise where does that leave us? All Wheel drive need a lift and new wheels fitted to the remaining wheels which are free spinning. This can also be used on ev's which have locked brakes on the non driving wheels

 
Last edited:
Yes with the driving wheels off the ground and not turning the motor it is fine. The problem with a normal ground tow is that even in N the motor is not disconnected from the drive wheels which could cause damage. With it rear lifted and steering locked, no brakes applied all should be fine as the drive wheels are not active. I suspect car could even be driven with no damage to be honest but the dealership probably wants to err on the side of caution. Also if you can't trust the AA expertise where does that leave us? All Wheel drive need a lift and new wheels fitted to the remaining wheels which are free spinning. This can also be used on ev's which have locked brakes on the non driving wheels

Thanks. I guess I've been made nervous by reading articles suggesting that you should never tow electric cars as neutral on an electric is not the same as on an ice, as the electric motor is never fully disengaged, and also there might be an issue with the regen brakes. Also I'm nervous about car damage to my new car, especially as the front of the car is quite low to the ground!

I agree with you about driving to the dealer, but I'm kind of snookered with that as the dealer and the AA has advised me against this.
 
I would hope the lift should not be as steep an angle as to affect the clearance at the front too much...or now rear whilst being towed...and potentially cause damage. As I said if you cannot trust the AA to tow 🤷‍♂️
 
Does anyone with more knowledge and experience than me know if its fine to tow an MG4?!
Just follow the manual.

eEJoNAm.png


56ki6jD.png
 
Update - AA man has been. Says it has a little oil leakage, not a lot, but agrees with the advice not to drive. He has booked a recovery tow to the garage in the morning. I said I wasn't sure that you could tow electric cars. He said it would be rear lifted, which would be fine as the car is a rear wheel drive. The manual says this, which I assume backs up what he says:

DO NOT tow the vehicle with any of the driving wheels in contact with the road surface, this will avoid electric drive transmission damage.

I'm still not sure that I am happy with this, as the dealer is 30 minutes drive away. Does anyone with more knowledge and experience than me know if its fine to tow an MG4?!
Isn’t there a setting somewhere in one of the menus to put it into when being towed?
 
Isn’t there a setting somewhere in one of the menus to put it into when being towed?
Interesting if there is but can't understand why...especially if the car is dead with no electronic option? Remember you cannot disconnect motor from drive wheels electronically so that's a no

Alan
 
It's the same problem with auto gearboxes. The driven wheels have to be suspended or as in a bus's case the half shafts are removed before being towed by the big truck with the yellow flashing lights.
 
Been for a drive today and took a look underneath when we got back ... I have my suspicions that it is leaking again. (Even though I've had the breather mod).

Will report to the dealer tomorrow.
 
Been for a drive today and took a look underneath when we got back ... I have my suspicions that it is leaking again. (Even though I've had the breather mod).

Will report to the dealer tomorrow.
This is a shocker if it is, still can't remember what member it was that explained what was going on in the gear box and how in their opinion it would need a full redesign.
The fact that we have had about 4 members all reporting their cars leaking post mod, In the last 2 days, might rule out human error.
If the mod doesn't work where do MG go from there?
 
Last edited:
This is a shocker if it is, still can't remember what member it was that explained what was going on in the gear box and how in their opinion it would need a fool redesign.
The fact that we have had about 4 members all reporting their cars leaking post mod might rule out human error.
If the mod doesn't work where do MG go from there?
Direct drive axle from the motor... No reason it can't take 5000rpm 😂😂😂

Been for a drive today and took a look underneath when we got back ... I have my suspicions that it is leaking again. (Even though I've had the breather mod).

Will report to the dealer tomorrow.
You can put your hand up by the rear left hand wheel suspension arm and feel the motor, mine has residue on it , but prior to the breather mod or was dripping with oil, so I'm confident its not leaking and is just left from the motor being cleaned up, and I do 20miles motorway and 15miles A/B roads every day during the week.
 
Some might argue a fool designed it in the first place :ROFLMAO:
I just like to say I fixed it before I saw this☺️ I'm blaming predictive text 😉

You can put your hand up by the rear left hand wheel suspension arm and feel the motor, mine has residue on it , but prior to the breather mod or was dripping with oil, so I'm confident its not leaking and is just left from the motor being cleaned up, and I do 20miles motorway and 15miles A/B roads every day during the week.
There have been 2 or 3 confirmed in the last 2 days unfortunately, quite messy ones as well to be fair
 
There have been 2 or 3 confirmed in the last 2 days unfortunately, quite messy ones as well to be fair
Not denying that it has reoccurred for some, just advising of a way of checking as the motor was literally dripping in golden oil on mine prior to the breather
 
Not denying that it has reoccurred for some, just advising of a way of checking as the motor was literally dripping in golden oil on mine prior to the breather
You would have thought and hoped that the modification would have been the end of it
 
You would have thought and hoped that the modification would have been the end of it
Unfortunately you're relying on humans to fix human errors, so there's always the potential for errors in fitting or errors in quality control at point of manufacture assuming it's been a machine that's put it together, if not errors in the assembly
 

Are you enjoying your MG4?

  • Yes

    Votes: 485 79.0%
  • I'm in the middle

    Votes: 83 13.5%
  • No

    Votes: 46 7.5%
Support us by becoming a Premium Member

Latest MG EVs video

New EVs from MG: MG S9 & MG9 plus hot topics from the forums
Subscribe to our YouTube channel
Back
Top Bottom