Hey all,
I am very new to my 85' 300D w123.
(I am new to cars in general, i.e. this is my 1st car ... so be kind if my questions seem silly)

I drive it once a week maybe for an hour. So it sits a lot.

Well I have noticed a nice pool of oil forming in my parking space. Its right about where the transmission is. So right behind the front tires if you look at the car directly from the side.

I check my oil level every time I fill up and have done a full oil change. The level is dropping but not by alot, and it is still within the recommended range.

So I am abit worried now and am wondering the following:

1. The guys who did my oil change said I have a "rear main seal leak" and a gasket(??) leak?. What are these and how bad?

2. How can I tell if the transmission is leaking or if it is just the engine oil that is pooling?
(I will check the transmission level once I figure out how ... that will probably answer my own question, but still any input or tips would be appreciated)

The big one:
3. The transmission shifts hard, it bucks or jolts the car, but it does shift into all gears. It doesn't slip into the wrong gear or anything, just the shift itself is rough.
It also seems to shift later than I would expect sometimes. I.e the engine revs seem to go way higher than I think they should before a shift happens ... What could this be? am I just imagining this?

Any help would be appreciated. Thanks

What color is the fluid? Red is ATF, Black is oil.

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

Thanks for the reply bgkast.

I pulled the car out this weekend and wipped up some of the oil with a white paper towel. There was two shades of oil. A pitch black one and a golden oil one. The pitch black must be from before my oil change and the golden from after. I wiped around alot but found no red.
I also got a hanes manual and figured out how to check the transmission level. Looks to be where it should.

So I guess the transmission isent leaking, just the engine oil. Thanks for sanity check.

As for the rough shifting, would anyone know what that could be? or how to fix it? (I will probably end up taking it to a mercedes mechanic but if its something simple i will give it a shot)

Thanks Guys ...

Sounds like you have a (classic) vacuum problem with your trans. Check out this link:

http://www.peachparts.com/shopforum/showthread.php?t=142395

Once my trans suddenly started shifting hard enough to squeal the rear tires on the 1-2 shift. Turned out the vac line to the trans had disconnected.

Might I suggest that you update your profile to display your location and create a signature with your vehicle info in it.

Charlie

__________________
05 E320 CDI - 175K miles
82 300D - 200K miles (sold)

huh ... I had my suspicions it had to do with the vacuum system!

The vacuum system in my car is very out of whack. I know the automatic door locks are powered by the vacuum system, and they don't work.

The driver side door makes a hissing sound sometimes when the door lock plunger is up. This is also when the shifting gets pretty hard.

Yet when I have the plunger down, the vacuum is sealed (the hissing stops and all the door locks actually lock) and the shifting does seem to be better. I thought I was imagining things though.

(what kinda weird car did I buy ??? )

I will research this and see how hard it is to fix. Thanks so much!

(i'll put in a sig this week )