R129 oil in the tranny bell housing.

[Chis]

First things first, hello this is my first post.

My car (300SL 24V) runs great no issues, but I have an oil leak that comes from the grate in the tranny bell housing.

My questions are -

If it is the fronts seals on the tranny (my ATF level seems unchanged), how much does this generally cost to fix?

If it might not be them and is engine side what would be the possible cause?

Has anyone used a stop leak product on this problem?

Thanks
Chris

 

[rorf]

Firstly how bad is the leak; is it dripping or only an oil mist. If either the engine crank seal is leaking or the transmission side then it means the transmission has to be removed to access them. Forget the oil leak snake oils.

 

[Bellow]

What colour is the leaking oil - the same colour as the engine oil or ATF?
When were the engine and transmission (I assume it has one) breathers checked?

 

[andy27168]

Hi,
To fix this regardless whether it is Gearbox or Engine oil it will involve the gearbox and torque convertor to be removed which is booked at about 4-5 hours to remove-install plus parts and whatever time fixing the leak takes.
I wouldn't be putting any additives in the oil.

 

[Chis]

Firstly how bad is the leak; is it dripping or only an oil mist. If either the engine crank seal is leaking or the transmission side then it means the transmission has to be removed to access them. Forget the oil leak snake oils.

Hi Rorf,

Thanks for the sound logic on the necessity of removing the gearbox either way, just trying to wriggle and see if this was avoidable. It looks like it is about a table spoon of oil every couple or 3 days (gravel drive hard to be specific).

Thanks
Chris

 

[Chis]

What colour is the leaking oil - the same colour as the engine oil or ATF?
When were the engine and transmission (I assume it has one) breathers checked?

Hi Bellow,

The oils in the car look almost identical so hard to guess which it is.

Only had the car a year now ( still bang in love with it), so could you give me more info on the breather situation as I a clueless?

Thanks
Chris

 

[Chis]

Hi,
To fix this regardless whether it is Gearbox or Engine oil it will involve the gearbox and torque convertor to be removed which is booked at about 4-5 hours to remove-install plus parts and whatever time fixing the leak takes.
I wouldn't be putting any additives in the oil.

Hi Andy,

Thanks for the labour summary, this type of info is pure gold as I like to have a rough idea of destination on any cash journey.

Thanks
Chris

 

[Bellow]

Hi Bellow,

The oils in the car look almost identical so hard to guess which it is.

Only had the car a year now ( still bang in love with it), so could you give me more info on the breather situation as I a clueless?

Thanks
Chris

ATF should be red in colour and should show its redness on white tissue.
Breathers on engine are to vent crankcase gases (blowby - the inevitable leakage of gas from above the piston past the rings) to prevent pressurisation of the crankcase. Nowadays fed back to the induction side to be reconsumed by the engine, any blockage can lead to build up of pressure and then leaks.
Trace the breathers back from the inlet manifold to the CC and check they are clear (blow through them).
Hopefully someone with specific knowledge of your car can advise exactly where located. Do this before shelling out on new seals as it may effect a cure and if blocked, will likely cause a new seal to fail (or find another escape point). Removing the oil filler cap with the engine running often reveals a build up of pressure.
If the oil is red, focus on the transmission. Same as above assuming it has a breather, but without the connection to the engine - merely venting to atmosphere.

 

[RichardF]

And shove a tray underneath when parked, to see.
a) How much
b) Colour

Be aware that the A/C drains condensation around the gearbox area. As it runs down it can pick up an oily residue.

 

[Stratman]

Although clean ATF should be red, worn out ATF is usually a mucky brown colour and may have a burnt smell.

 

[BlackC55]

It could be coming from the oil cooler at the back of the head too. Get it looked at by a competent mb tech.

 

[Chis]

Thanks folks, got a few things to check on now, which is something I enjoy and I accept as part of the charm of owning a lovely older MB.