W203 sportcoupe underside gearbox cover leaking

[cplnoonoo]

Whilst i had the car on the ramps i noticed that the black tray on the underside of the gearbox was covered in what looks like gearbox oil. I cleaned this all off and a closer look reveals that it may be leaking out from around the gasket.
Is this a common fault for the gasket to go on this section or does the cover just need tightened up? Its a w203 sportcoupe 04 prefacelift.

It doesnt look like anything has been dripping onto the driveway since i got home and there was nothing there when i checked this morning.

Im not sure how long it has been this way so it may have just happened yesterday so i shall have another look underneath the car towards the end of the week and see what sort of condition the cover is in. It does look like it is leaking out very slowly so im not sure if ill find anything when i next check.

 

[cplnoonoo]

This is a photo of the cover that i have borrowed from google. The cover is basically outlined by the numbers. Should this be covered in gearbox oil (or atf fluid...not quite sure) or should it be dry as in the photo.

 

[jaymanek]

It will be the gearbox electrical plug. We have done three today... They are such a common failure I keep a good stock.

Around £15 from the dealer.

 

[cplnoonoo]

Gearbox electrical plug? The whole of that black cover had oil all over it. How does an electrical plug come into play? What does it affect that causes an oil leak to cover that black cover? Sorry not to clued up on the gearbox side of things.

 

[jaymanek]

The electrical plug is above number 1 on your picture, up at the side of the gearbox... This leaks oil past its seals and then the oil goes everywhere...

 

[cplnoonoo]

Will this be causing a bad leak or could this have been a slow leak going on for a few months?

Something that i should replace as soon as?

 

[momomo]

Its a slow leak probably leaking for a while already. You can still drive the car but should get it changed as soon as really. Then get the gearbox level checked and topped up if need be.

 

[cplnoonoo]

Yeh will do. Dunno if youve noticed a lot of my posts recently have been trying to solve problems with the motor. Only got the car in october and not even done 2000miles so keep having to go back to the garage i got it from.

The garage is a honda dealership but its run by a family and 2bh the service you get is brilliant its just this time the cars sneaked out the back door and not been properly checked. So i will check the underside again tonight and see if its covered again as i cleaned all the oil off when it was on the ramps so i should be able to see if it has leaked enough onto the cover that i can show the garage and tell them to fix it.

1st merc aswell and one of the main reasons i got it was that they had a good reliability record and was hoping to get it to last for a while. Not the best start lol.

 

[jaymanek]

The plug is a common complaint and once it starts to leak it can get quite bad,,, you should change it before it ruins the gearbox.

 

[cplnoonoo]

Will have a quick look tonight and see how bad it is leaking as i cleaned on sunday so should be able to tell. will have it at garage before end of week regardless.

 

[cplnoonoo]

Sorry to have to reincarnate this thread but i had the gasket replaced on the bottom of the box back towards the end of april and all has been fine (or so i thought).

The gearbox did not stop dripping oil and i never realised this as the driveway was still stained from the previous leak and i didnt see the fresh drops on the driveway. Was washing the car at a friends garage and noticed brown streaks in the snow foam so put it on the ramp and had a look and the whole underside was covered in oil.

Could it be the garage has not fitted the gasket properly or could my problem lie elsewhere?

My dilema now is that the cars warranty expired at the end of april and i had the box repaired just before it expired but not it is leaking again i am out of warranty so i hope they do the work free as they obviously have not fixed as they should which was done whilst it was under warranty. Am i right that they should rectify this fault?

 

[jaymanek]

did they change the electrical plug i mentioned?

 

[cplnoonoo]

Only the gasket as far as i kno. Not certain tho as i forgot to ask them for a report of the work actually done.

Could this be the source?

 

[jaymanek]

yep.. change the plug before anything else.

 

[cplnoonoo]

Do you reckon thats something easy enough to change myself or is there a lot of work involved?

 

[jaymanek]

well they can sometimes be stuck..
procedure is remove under tray, disconnect plug, undo the bolt inside the plug (7mm?) and then remove the "pilot bushing" as its known, replace with new..

You will probably lose some oil and this will need to be checked and topped up.

 

[cplnoonoo]

Which tube under the bonnet is for topping up the gearbox oil as there is the pipe with red lid and the pipe with the black lid. Can i pour it straight in one of those to keep it topped up until i gt it to the garage?

 

[cplnoonoo]

Right so the car is back in at the garage this morning and they are going to investigate. They had down on the jobsheet that they had replaced the gearbox sump last time (which was under warranty at the time) so hopefully they will find the problem and sort it but at no cost to me.

I will post up results at some point today or tomorrow when i hear back from them.

 

[cplnoonoo]

UPDATE:

Got the car back 2 Fridays back (9th July) and all was well. The reason they stated for it leaking after the initial repair was that they had forgotten to use a sealing kit on the gasket when they had replaced it. So they used this kit and replaced the gasket with another new one. They also greased up 1 of the seals on the electrical plug mentioned earlier in the thread as this was all that was required as far as they could tell. Seemed to be alright until i smelt burning oil last Friday (16th July). Got it on my mates ramp again and sure enough the underside was saturated in gearbox oil yet again. The burning smell was the gearbox oil dripping down and blowing onto the back part of the exhaust and burning off.

This was less than a week that had past and it has been spewing out. It is a clean and clear red colour so it is definitely gearbox oil and as it was practically refilled from empty less than a week ago on friday the oil was brand new that was leaking out.

Have got back onto the garage to get it booked back in and they have managed to squeeze me in on Wedsnesday and have told me they will keep the car until further notice. I mentioned to them that they obviously have no idea what they are needing to fix/replace so i would possibly be taking to the dealership here in dundee and get them to bill the costs straight to the garage. They quickly objected to this stating that "they (mb dealer) would just want to put a new gearbox in and we cant authorize that im afraid."

Maybe that's what the car needs. Could the box casing actually be cracked and that's why they cant find the leak?

They kept the car overnight last time after they had fixed it to check that it wasnt leaking after the second repair and it all seemed fine. Maybe its only leaking after being under load for a extended period of time?

It's starting to really annoy me as it should have been sorted the first time and this is now going to be the third attempt at a repair. Here's hoping they get it right this time lol!

 

[BlackC55]

Did they replace the pilot bushing?