wizkid

2002 C240 2.6L motor Automatic - 134,500 miles

What do you make of this? Is this just a seal leaking and how hard would it be to change or is it even worth the trouble? Also, where do you add more fluid and does MB want gear oil or Auto Tranny fluid in the diff?



Thanks

sosh

Looks to be a seal. As far as the fluid is concerned that info should be in your maint booklet with all the other approved fluids.

BeNzTeK

Yea man that is a rear differential seal leak when you have this done make sure you do both sides!! and you mine as well do the pinion seal to while your at it....no sense in paying twice for 40 dollars in parts.
BTW I would get this done
If you look at your picture right where the leak ends on the bottom of the diff you will see a drain plug you can drain it there and then to fill it there is a fill plug you have to look above the axle shafts I cant remember which side it is on but changing the fluid is not going to do anything for you...

wizkid

Thanks. How hard of an install is changing the three seals? Does it require any special tools or training? I am thinking about jumping in and changing them out myself and then do a writeup. I have never seen a MB chunk but I hear the gearing in the rear differential is extremly exotic compared to my Camaro.

I don't want to jump in another install ( See this mess ) and find out how big a job it is.

Can you offer some advice to benifit me on this?

BeNzTeK

Well It is not that hard of a job to do First thing first:
When you put the car up leave it in neutral
Drain rear end fluid out!
Take both axle shafts off ....(you will need fire , hammer,inverted torx ,and these bolts come off alot easier with like a 3'8 impact gun
once axle shafts are off
Remove driveshaft from diff.......
you will then have to remove the drive shaft there are 6 long bolts and they connect the diff to the rubber hardy disc to the driveshaft.MARK THESE BOLTS THEY NEED TO BE PUT ON LIKE THEY CAME OFF!!! Let the driveshaft hang and make sure you mark the drive shaft to its position on the hardy disc.

After you have done this Remove all mounting bolts there are usually 2-3 mounting bolts 2 that connect the front plate of the rear end to the sub frame and one long allen bolt with a 17mm.. nut holding this in on top.(try finding an old 17mm wrench and cut it in half cause you will need to hold the top of this nut to get the allen bolt loose/out!!!

Then unplug the speed sensor NOT FROM THE SIDE OF THE DIFF THESE ARE NOTORIOUS FOR BRAKEING OFF INSIDE THE DIFF!! follow the speed sensor wire it should lead into the trunk mark it and remove!.
THen remove diff from car and set on a sturdy table

Remove front plate there are about 10-12 torx bolts remove cover with scredriver/hammer.

Looking into the diff at the gears you will see two side gears that would lead out to where the axle shafts would connect inside there are 2 c clips get a hook tool remove these DO NOT LOOSE THEM becarfull they will fking out.
After this remove these to sliding gears and your seals are right there.

Take them out with scredriver or seal popper tool
Clean the grooves grease new seal and lightly tap the new seal in try using the old seal and place it ontop of the new one use a small piece of wood and tap lightly you dont want to damage the new seal !!

(mark that seal before you pull it out so you know how deep to put in the new one)
Good luck if your gonna do the pinion seal let me know and i will give you instructions.
BTW these are brief ****ty instructions I am really tired of typing

wizkid

I have a good friend who is a GM tech, he said the rearend is the same as the Chyrsler LX (I may have that vehicle wrong). He thinks we can replace the one seal without too much trouble (read: not remove entire pumpkin).

He has the seal proper tool at the dealership I can borrow. We are just going to replace the one seal at this time.

I am going to order two seals today and we may replace the other.

Do you think we can replace the seals easily without taking the differential housing out and not removing the driveshaft?

BeNzTeK

you can leave it in with the driveshaft still hooked up but your still going to have to lower it to take the front cover plate off

wizkid

No doubt. I have a scissor lift coming (sits in the jack tray, I am sure you know that though ) for my lift that will raise the rear body of the car so I can drop the differential and do tire and brake work on my lift.

I will report back when I get closer. I can't start until I get the lift which may be as long as two weeks away.

wizkid

I couldn't get the part ordered because of computer problems at the dealer. So, when I call back, do I just order a "rear axle seal"?

MBTech21

It's called a differential side seal.

And the BTW- the instructions are all wrong- you have no bolts to remove the axles- your axles just slide out- after the wheel carrier assembly is removed- huge job. And we haven't used sensors in the diff for years... so benztek was off a bit.
To answer your question, with thie axle setup, you can do it in the car, but the other style was way easier!!!

BeNzTeK

Yes I am sorry For some reason I was thinking this was clk .....THAT HAS THE SENSOR in the Diff and they stopped doing that in 2002 not that long ago bud........

wizkid

Does this look like the correct diagram?


< removed PDF link >

I am going to pick the part up right now.

MBTech21

Yes, thats it..

BTW, just to cover you..MB is getting kind of uppity about their info being posted on the web/copied,etc.. Probably 2 many WIS CDs on ebay,etc..probably not a great idea to post stuff like that..

wizkid

Cool. Thanks for the tip on the posting PDF too. I just got my new DVD Star Service manual from the dealer today.

How do I tell what rear end and transmission (722.6)? Is it on the car or do I have to get a report printed from MB with VIN about my car?

I am waiting on the Jack to do the swap so i can lift the body of the car dropping the pan down to access it. It may be another week before it comes in.

BTW, MB is also proud of their gear lube. $19.50 per quart.

wizkid

Can the dealer tell me which tool I need to order to install the seal? They list two tools for the same job and how I am supposed to know which one works?

Also, what does "drift" mean?

TIA!

MBTech21

Drift is something you hit with a hammer. That means ether one will work.
If the dealer runs the VMI for you, it will have all your numbers, but your trans is a 722.6xxxxxxxxxxx. Which ususally is all you need to know

c240MBenz

what happened to your write up? regarding instal ?