Hi All,

just finished sorting out and refreshing the suspension for a 1987 300E auto I bought that was sitting for about 4 years. It runs fine, but there's a pretty massive transmission fluid leak somewhere, and also an oil leak, so I figured I need to yank out the transmission and engine and just do a full reseal, and probably a head and valve job while I'm at it.

I've been reading through old posts and just wondering if anyone knew what parts I should go ahead and get and handle while I'm in there? I was thinking of getting one of the full transmission refresh gasket kits, is that worth it? Also dropping the trans filter and etc.

What about for the engine? Any particular brand of head gasket to use?

Any other things I should get?

Best,
Martin

Maybe its something simple like a dipstick tube seal or a pan gasket? Rear seal likes to go as well. Would be silly to take out the powertrain just for that.

You can smoke test the transmission through the dipstick without oil in trans to see if it's something simple.

But I agree with you that taking out the powertrain would be the way to do it if it's more serious or if you just want to make the car more reliable.

Because it's an 87 I would check for camshaft wear. Timing chains dont last more than ~140k on these engines so check for wear on that too.

Head gasket brands - elring or geniune mb (I think that the genuine one is made by elring anyway)

Genuine on the head gasket. Fair chance it will need valve guides, early M103's had problems with them.

Good luck!!!

__________________
"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Not all early m103 suffer from worn guides and then it's only the intake guides.

If it runs smooth and doesn't burn oil I would leave them.

The leak seems to be coming from the perforated housing between the engine and trans. So I'm assuming that means front seal. Is that not correct?

The engine has 240k miles, and I figure with the engine out I should just go ahead and do the head because I already have it out. Also I think I'm leaking oil from the head gasket as well. There's an oil leak somewhere, though it could be the valve cover gasket.

I am presuming it is an automatic transmission.

I am in the process of doing this but got stalled by having to work on other vehicles. That means my Trans is partially apart.

Mine leaks front and back and I believe where the shift shaft comes out of the side of the transmission.

In the Front Kent from Mercedes Source suggests that as well as the Seal the Pump O-ring and or gasket can go bad and cause a leak.

In order to get those off you need to remove the Front Pump and take it apart. In order to do that when the Front Pump comes out the Reverse Piston is attached to it.
To get the Revers Piston off you need to depress a spring plate in order to get out a retaining ring. Once that is off you can get at the bolts behind the front pump and take the front pump apart to get at the O-ring.

What I found is that O-ring was so stiff it cracked on removal. So I am glad I took the effort to look. I am also replacing the 2 seals on the Reverse Piston which seemed somewhat inelastic.

Also inspect the pump front bushing. If it is too worn that allows more pressure to be applied to the front seal. Also there is where the seal lip rids on the Torque Converter.

I have not replaced anything yet as I have not ordered parts.


Due to age you might consider replacing the B2 piston rubber lip seal and because you removed the cover you will likely need a cover O-ring.

I am not sure what updates were done by your year and model in the B2 piston area.
On my 84 300D the Aluminum Bushing is replaced by a updated Nylon one, the mentioned Lip Seal and in my case the B2 Piston itself (mine was broken) with the updated Piston and of course the mentioned cover O-ring.

I am replacing the shift shaft bushing because there is not a lot of room to do it on the vehicle and it does not cost much.

I can't remember if it takes a 30 or 32 mm 12 point deep socket to get the output shaft yoke off of the rear of the transmission.

On mine Mercedes does not have a part number for the front pump bushing but it is available from other sources. With a visual inspection I believe I will be leaving it alone.

__________________
84 300D, 82 Volvo 244Gl Diesel