MG4 Reduction Gearbox Oil Leak

[tsedge]

This is a prime example where a simple statement from MGUK would explain what is going on and avoid a lot of hassle and worry.

 

[Deleted member 10041]

This is a prime example where a simple statement from MGUK would explain what is going on and avoid a lot of hassle and worry.

Agree simple thing to put out and keeps the customer up to date. Faults happens it's how the fixing and communication goes that annoys people.


sur mon meilleur comportement aujourd'hui

 

[AndyL61]

Agree simple thing to put out and keeps the customer up to date. Faults happens it's how the fixing and communication goes that annoys people.


sur mon meilleur comportement aujourd'hui

Is that a comment from the French Troll?

 

[Ayoull]

Mange tout @Leni16 mange tout

 

[Ian Key]

Agree simple thing to put out and keeps the customer up to date. Faults happens it's how the fixing and communication goes that annoys people.


sur mon meilleur comportement aujourd'hui

Le jour est encore jeune

 

[Cocijo]

The one in the picture above is the one fitted to my car and there is a newer, longer one which is being fitted at the factory only so I was told by Tech Manager. He showed me a pile of breathers on his desk in plastic bags which were for existing cars and that was the same as mine. He then said new cars now come with a different one - his point was, why are they not sending the latest when the fault is logged.

Do you know if MG are fitting these modified breathers to all cars now?

 

[AndyL61]

Do you know if MG are fitting these modified breathers to all cars now?

Mine came with modified breather. Had it 2 months, 3k miles , no leak.

 

[Cocijo]

Well that sounds positive.

 

[AndyL61]

The one in the picture above is the one fitted to my car and there is a newer, longer one which is being fitted at the factory only so I was told by Tech Manager. He showed me a pile of breathers on his desk in plastic bags which were for existing cars and that was the same as mine. He then said new cars now come with a different one - his point was, why are they not sending the latest when the fault is logged.

They probably got a load of these made before they discovered they don't always work and are fitting them in a vain hope that it cures the leak. Eventually the penny will drop and all cars may then get modified.

 

[Macadoodle]

They look almost identical, so not sure what the difference is unless as I suspect that the mark 2 may not contain a ball valve, which would eliminate pressure build up and spitting effect.

When I fitted the ball valve to the end of my 'megapipe' that terminated behind the rear bumper, it did seem to act as a pretty effective one way valve.
Big slugs of oil would just hang in the clear tubing and not drain back to the box, just made the leaking worse as far as I could see. Not that eliminating the valve made the leak go away mind you.

I notice that the gearbox in the pics does have an oil filler / level plug, has 'oil' written on it. Looks like the oil level comes half way up the intermediate shaft so its only the motor output gear and its support bearing that's relying on oil splash.
I'm betting filling that casing to the bottom of that plug hole takes 900ml of the slippery stuff.

 

[Deleted member 9692]

Do you know if MG are fitting these modified breathers to all cars now?

He told me that new orders were coming through with a new breather now (different to the one that is still being retrofitted) that’s all I can tell you

 

[Deleted member 10041]

Le jour est encore jeune

la nuit est beaucoup plus longue et c'est alors que les trolls sortent

 

[maverickz]

Waylands claims this is the latest version from MG UK.
All I can tell is the jubilee clips replaced cable ties.
And they only put in 700ml oil instead of 900ml in the manual.

 

[siteguru]

700ml + about 50ml probably still lying in there = 750ml reduced level that was first mooted.

 

[Alb]

I'm betting filling that casing to the bottom of that plug hole takes 900ml of the slippery stuff.

That is the key issue.
If 700ml were truly a correct figure, the hole would be in the wrong place!

 

[JuziWomble]

I'll find out in a few weeks what they will fit in mine ...

 

[spence7788]

Just a quickish post as I've finally done the diff oil change today, I took a few pics along the way but any questions just fire away.

It was pretty simple just remove the undertray with a million fixings, remove the square drain plug, drain the fluid (& measure) then replace drain plug. Remove the 17mm hex fill plug and refill oil with desired measurement then replace fill plug.

the only issue I came across was my suction oil filler & funnels were useless so after getting oil all over the drive , I went and bought a 1l laser mini pump from Halfords which I was super impressed with & had it refilled in about 2 mins from underneath. I've ran out of time as it started throwing it down but I'll get the undertray back on tomorrow but it's done.

soo.......I wasn't surprised to see some evidence of oil leaking underneath but I'm pretty confident it's not recent & was probably from when they fitted the breather or before and filled it with whatever amount of oil then, they were pretty vague on details at the time and it seems impossible to speak to a tech!

basically the oil was black & filthy as expected, I drained exactly 650ml out but I'd say there was probably another 50ish ml came out in drips and on the drain plug etc. As can be seen on the cardboard I left for a while & whatever is clinging to gears inside etc. so I reckon I've had 21k of pretty spirited miles with around or just over maybe 700ml in the diff.

What did suprise me initially was the state of the magnetic drain plug which had shavings all over it, after speaking to a couple of very trusted mechanic mates they've assured me that's relatively normal on any manufacturer first diff change, most of it during the first couple of k whilst it's being broken in and nothing to be worried about & there shouldn't be much on the next one etc. After a bit of research I'm not too worried about this as it seems there right.

basically the oil imo needed doing, possibly it's working harder not having the 900ml in or maybe I'm just anal with oil & it would have been fine forever but I feel alot better with it having fresh oil on there, I'll be doing this every 20k as bar the undertray it's a very simple job tbh & reckon it should be done alot sooner than the 72k I believe MG recommended .

I put a tad over 800ml back into the diff, I half expect to get a little leak whilst it may find it's 700ml ish level again or maybe that's all they filled it to when the breather was fitted? I'll keep an eye on it anyway and see what happens.

thanks again Macadoodle for the tips etc. Pal.

 

[spence7788]

Some random ones

 

[jpk]

Some random ones

Were there any aluminium/copper crush washers that you had to replace or was there a washer with rubber gaskets bonded to them already fixed on the drain plugs

Edit: I can see from one of your photos that there are aluminium crush washers. What the inner diameter and what torque did you re tighten to?

Also I can see the rear anti roll/sway bar is easily accessible so I'll be looking to fit an updated one when one becomes available

 

[spence7788]

Were there any aluminium/copper crush washers that you had to replace or was there a washer with rubber gaskets bonded to them already fixed on the drain plugs

Edit: I can see from one of your photos that there are aluminium crush washers. What the inner diameter and what torque did you re tigh

There were washers on both the drain & fill plugs but I just did as Macadoodle did and did it by feel & just re-used them as unfortunately any workshop info is nigh impossible to get unless you know a tech etc. atm Really can't wait until hopefully someone gets a copy & made public.

I'll double check everything again before putting the undertray back on tomorrow but I did check a couple of times and it was fine.

I did take off the smaller rear undertray (one pictured) to get a better look at everything but this isn't needed to change the oil but yeah, I've done alot of winter miles in snow/salt and it looks filthy but everything to be holding up well bar the driveshaft outers but that's just cosmetic.