MG4 Reduction Gearbox Oil Leak

[wiz043]

Is it possible that the leak-proof modified breather has an extension inside the box that takes the entrance to the breather away from the oil being thrown up by the gears?

From previous reports it has a longer spout which is angled differently and may or may not work. The problem is that no one knows whether the oil level was reduced as well.
There is no definite response from MG or dealers as to the fix to my knowledge...they just say the issue has been addressed.

 

[Hagen]

Unless there's a fundamental change to the design inside the box I would be very surprised if there's any way to stop the leaking with the current breather position and a decent oil volume inside.

I tried and tried. Now I know I don't have a team of clever engineers at my disposal but I saw first hand the eruption of oil every time you have 700ml or more in there.
Regardless of how long a pipe you use or how much you restrict it, or enlarge it, or coil it, you name it, it didn't work.
It's been over a week and I've covered more than 300 miles with the side mounted breather with a short pipe installed in the box's fill hole.
Pleased to say that the leak is no more, and I'm running with 900ml (refilled with 850ml allowing for some residual oil )
Unless MG has a recall to strip the gearbox and properly retrofit an oil deflector or whatever it actually needs I'm just going to stick with my own setup for as long as I own the car, at least I know it's getting lubricated which is the main thing.

You have found a solid solution, great job! Good to hear its still working.

I hope that someone with 'model year 2023' MG4 will make a video/picture off the gearbox. Hopefully there's no 'L pipe longer breather' on it, but the original one-way breather. If so, I am quite sure they changed something inside the gearbox. And thereafter the volume fluid must also be checked, but that's step 2.

If the 'L pipe' solution is still on the gearbox, then its seems to me that its the same 'model 2022' gearbox and we can stop asking people what's digit 10 in the VIN.
Agree?

 

[Les burrows]

Me I’m going for oil level reduction has been approved by some one at the factory and nothing else,quick easy get out and cost saving to boot RE 200 ml of expensive gear oil x maybe a million vehicles worldwide mounts up.
Les

 

[Hagen]

There appears to be a pattern with the 2023 models not leaking according to the research here but I wonder if these cars have a modified breather or just have less oil put in them at birth or both as indicated by @Hagen. Dealers would not know and the Chinese manufacturer is certainly not going to tell anyone...they are renown for keeping secrets.
What we need is for someone who knows the 'old' breather design to check the latest model breather type and the amount of oil in the reduction gear box but I don't know how that can be achieved as I doubt dealers would be any help.
I applaud @Hagen for taking the time to do this research and it would be great if it is proven that those vehicles built after a certain date do not have this issue but my main concern is whether MG 'solved' the problem by a bandaid fix of just sharply reducing the amount of oil put in the 'box.

If the original one-way breather is on top of the gearbox, without the 'L pipe', on the model year 2023, I am quite sure MG changed the inside of the gearbox. If not, I think its 'bandaid fix of just sharply reducing the amount of oil put in the box'.

 

[AndyL61]

You have found a solid solution, great job! Good to hear its still working.

I hope that someone with 'model year 2023' MG4 will make a video/picture off the gearbox. Hopefully there's no 'L pipe longer breather' on it, but the original one-way breather. If so, I am quite sure they changed something inside the gearbox. And thereafter the volume fluid must also be checked, but that's step 2.

If the 'L pipe' solution is still on the gearbox, then its seems to me that its the same 'model 2022' gearbox and we can stop asking people what's digit 10 in the VIN.
Agree?

My PN0 vin car definitely has the modified Z shaped pipe breather. I took the ns rear wheel off and checked it myself. I will not be draining the oil out to check the level as I really don't have either the time or facilities to do this easily. Once the car has done around 20k miles I may consider doing an oil change if I can.

 

[Macadoodle]

Me I’m going for oil level reduction has been approved by some one at the factory and nothing else,quick easy get out and cost saving to boot RE 200 ml of expensive gear oil x maybe a million vehicles worldwide mounts up.
Les

My gut instinct agrees with that.
Most definitely those of us with the standard leaky box will never be helped properly, it would mean a recall and extraction of the drive unit to fit an internal baffle or maybe even a new gearbox casing with a repositioned breather, it's never going to happen IMO.
A change of design at the factory would cost practically nothing, a bit of metal to deflect oil or side mount the bloody thing like I did.
Surely they can manage this at some point ?

 

[Hagen]

My PN0 vin car definitely has the modified Z shaped pipe breather. I took the ns rear wheel off and checked it myself. I will not be draining the oil out to check the level as I really don't have either the time or facilities to do this easily. Once the car has done around 20k miles I may consider doing an oil change if I can.

Thx AndyL61. Disappointing however. ?

My gut instinct agrees with that.
Most definitely those of us with the standard leaky box will never be helped properly, it would mean a recall and extraction of the drive unit to fit an internal baffle or maybe even a new gearbox casing with a repositioned breather, it's never going to happen IMO.
A change of design at the factory would cost practically nothing, a bit of metal to deflect oil or side mount the bloody thing like I did.
Surely they can manage this at some point ?

Your instinct was right ?

I hoped to find a change in the VDS part of the VIN. Some manufactures do that when they changed the gearbox for example. The only change I saw was the building year to 2023 end september but with the same Z-pipe as building year 2022 and probably the same lowered fluid in the gearbox. Disappointing, but it was worth a try.

Thanks for your input!

Location - England
Built - September 2022
Leak - No
VIN - LSJWH4093NN1*****

Thanks for you input, but I stopped the 'research'

 

[Les burrows]

My gut instinct agrees with that.
Most definitely those of us with the standard leaky box will never be helped properly, it would mean a recall and extraction of the drive unit to fit an internal baffle or maybe even a new gearbox casing with a repositioned breather, it's never going to happen IMO.
A change of design at the factory would cost practically nothing, a bit of metal to deflect oil or side mount the bloody thing like I did.
Surely they can manage this at some point ?

This is very much what I wrote at#2760 Wow.
Macdoodle you have done the best you can and one again I say thank you on behalf of many here on this and other forums.

MG will do the least they need to do and we all know what that is, whoever designed the gearbox unit said 900 ml of oil is required but somewhere someone as said 600ml will do.

This is very much how Bungalow homes came about when one morning on the building site, the brickys where was building a two storey homes went to the foreman and said, boss we have run out of bricks for the top level and the foreman scratching his head said.

Ho for gods sake Bung a Low roof on it.??

Les.

 

[AndyL61]

I hoped to find a change in the VDS part of the VIN. Some manufactures do that when they changed the gearbox for example. The only change I saw was the building year to 2023 end september but with the same Z-pipe as building year 2022 and probably the same lowered fluid in the gearbox. Disappointing, but it was worth a try.

Thanks for your input!

Due to the fact that MG will never want to admit to a design flaw in the first place, they also are unlikely to admit to a design change. So it could be that a simple and therefore cheap internal modification could have been done and the Z pipe breather fitted for extra reassurance. This is something that we will never know unless someone removes their gearbox. So everything we are saying is conjecture, it could be true but conjecture none the less. Thanks for your efforts, and also Macadoodle , just wish MG customer support would put the same amount of effort in .

 

[MarcS]

It's quite possible. An oil 'mud flap' would seem to be a necessity if you're going to mount a breather in the direct line of spray from the gears.
Not sure if the diff ring gear or the others are force feeding the breather, but at 60 mph you have some gears spinning at maybe 8000 RPM
This box acts like it simply doesn't have anything to deflect this. Design or forgetfulness ? only they know .

As for the state of the factory fill I drained, TBH the colour probably looked worse in the pics than in reality, although it wasn't great for sure.
Break in particles suspended in it, didn't smell burnt or anything, but certainly better out than in.

What worries me more is the fact that the unit relies on oil throw to lubricate the upper components and the breather lets the box leak via this action, until the throw must be minimal.

What's that doing to these components long term ?

Can you post a photo of your final solution, I have only found the early temporary one and materials used.

 

[Macadoodle]

Can you post a photo of your final solution, I have only found the early temporary one and materials used.

I'm still using what is pictured in post #2749 of this thread. It has 250mm of 8mm clear tube attached to it with the end blanked off with a piece of plastic drilled with a 3mm hole.
I'm still waiting on a brass elbow fitting on the slow boat from China, once I get that I will make up a slightly more elegant design and post pics of the finished article.

 

[Les burrows]

Hi again Macdoodle sorry to trouble you again , but if possible it would be most helpful to all if you could list part/item or order numbers with any pictures.
Thank you
Les

 

[Gilles]

Good morning Macadoodle.
I am following your work closely and I admire your persistence in solving the problem of oil leaks from the gearbox/differential block breather. But I have a suggestion: why not implement this type of breather which is used in competition on gearboxes?
Gilles

 

[Macadoodle]

Good morning Macadoodle.
I am following your work closely and I admire your persistence in solving the problem of oil leaks from the gearbox/differential block breather. But I have a suggestion: why not implement this type of breather which is used in competition on gearboxes?
Gilles
View attachment 16178

Thanks for the suggestion Gilles. To be honest now I've fitted a simple short tube to the side of the assembly via an adaptor screwed into the filling hole, I've not had any further leaks.
I'm going to refine it further with the correct brass 90 degree connector and shorten the pipe so it runs vertically straight from the outlet to just under the boot floor.

The change to side mounting was the critical thing it would seem, everything just worked after that

Hi again Macdoodle sorry to trouble you again , but if possible it would be most helpful to all if you could list part/item or order numbers with any pictures.
Thank you
Les

Think I posted ebay links to the sump plug adapter and brass elbow back in the thread Les.

Other than them, just a piece of oil resistant tube and something to block the end of that tube you can drill a small hole in, I just found a random bit of plastic rod that fitted snugly.

I'll post pics of the refined design when I get that brass elbow from China ?

 

[Auto Surgeon]

I'd of thought you'd be able to get most of those components from the likes of Hyphose.

 

[Deleted member 10041]

Good morning Macadoodle.
I am following your work closely and I admire your persistence in solving the problem of oil leaks from the gearbox/differential block breather. But I have a suggestion: why not implement this type of breather which is used in competition on gearboxes?
Gilles
View attachment 16178

Everything Macadoodle has done has to be commended, hats off to him for the effort he has put in.

I do believe it's about time that MG themselves step up and sort it out!

And not just by lowering the oil level to about 600mls, so that it can't leak(not won't leak) as has been speculated upon

 

[AndyL61]

Everything Macadoodle has done has to be commended, hats off to him for the effort he has put in.

I do believe it's about time that MG themselves step up and sort it out!

And not just by lowering the oil level to about 600mls, so that it can't leak(not won't leak) as has been speculated upon

Agreed, and he could probably make a few shillings by putting a kit together and a set of instructions for anyone who can't get MG to fix it properly.

 

[Les burrows]

Agreed, and he could probably make a few shillings by putting a kit together and a set of instructions for anyone who can't get MG to fix it properly.

Now this is good thinking and I like it but I think Macdoodle might have had enough, it’s great that it now appears to be doing a great job in avoiding the problem my only worry would be about warranty, it shouldn’t be an issue but we all know all vehicle manufacturers only need the tiniest amount of wriggle room.
Les.

 

[Cocijo]

It will be interesting to see how things go when the outside temperature increases through the summer.

 

[AndyL61]

Ok I am back from my Cornwall road trip and I'm happy to report still no oil leak. I'm beginning to think that there must be more to it than just the Z pipe breather mod or there is very little oil in it ! Now at 2700 miles and plenty of motorway driving.