Author Topic: W108 "Beverly" transmission leak questions  (Read 709 times)

K-Jet

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W108 "Beverly" transmission leak questions
« on: July 31, 2022, 18:28:44 »
Again, for my 1971 280SE, Horizon Blue with blue MB Tex interior. California refugee, like so many....

Over the time I've had the car I've gone through the brakes and exhaust, the interior and fuel system, the cooling system and the engine tune to the point where the installed 250 motor runs really well.

The one remaining obstacle to getting the car on the road is the transmission. Specifically, its refusal to hold oil. The beautiful, red, expensive transmission oil leaks out through the vent below the torque converter. I've had the transmission pulled, and it seems to me that the only way to get transmission fluid into the torque converter space is if it's leaking from around the input shaft. And indeed the input shaft will wiggle 1-2mm side to side.

Am I on the right track? Are there user serviceable parts inside? The only professional help I've been able to find offers a 2500€ rebuild to solve all my problems, but I'd rather not unless I have to.
Dru
_____
1971 280SE "Beverly"
1990 250D 5-speed "Opa"
1995 E220T Sportline "Sportwagon"
1980 911SC Targa "Petrol"

ja17

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Re: W108 "Beverly" transmission leak questions
« Reply #1 on: July 31, 2022, 23:24:13 »
Check to see if your torque converter has a hub which is riveted in place. Sometimes this version leaks oil as the rivets loosen with age and use. There are three possibilities for leakage from the bell housing; the converter, the front transmission seal, or the large O-ring around the front pump housing.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2006 Mercedes Sprinter Van
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

K-Jet

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Re: W108 "Beverly" transmission leak questions
« Reply #2 on: August 03, 2022, 15:42:40 »
Thank you. I'll amble across the street and have a look at the torque converter.

Any concern about play in the input shaft? Could the brass bearing be shot?
Dru
_____
1971 280SE "Beverly"
1990 250D 5-speed "Opa"
1995 E220T Sportline "Sportwagon"
1980 911SC Targa "Petrol"

ja17

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Re: W108 "Beverly" transmission leak questions
« Reply #3 on: August 03, 2022, 19:46:54 »
The brass bearing usually is not the source of a leak. However the bearing can be damaged if the torque coverter is not installed all the way engaged during installation.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2006 Mercedes Sprinter Van
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

Todd

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Re: W108 "Beverly" transmission leak questions
« Reply #4 on: August 04, 2022, 00:28:34 »
Because transmission fluid is very high detergent, you will be able to identify the leak source fairly easily, as it will be the cleanest area.

Once installed, I'm guessing your amount of play will become zero due to the TC (torque converter) being bolted to the flex plate, which is bolted to the crankshaft.

Have you thought about taking the transmission to a specialty rebuilder, who's familiar with them, and ask to have the front seal, pump, and pan gasket replaced, have them install the TC, and then wire tie the TC in the installed position so that you can install it yourself. Leave the wire ties in place until you have the transmission very close to it's final install point. This will keep the TC from sliding out of the transmission and damaging that seal.
Todd

K-Jet

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Re: W108 "Beverly" transmission leak questions
« Reply #5 on: August 04, 2022, 14:46:15 »
Todd,

I have contacted a number of transmission shops around the country, and most don't want to touch anything this old. The ones that do want to do a full 2500€ rebuild. So I think I'll have to find my way through myself, with the help of you and those on the board here (and the BBB).

Thanks for the wire tie tip.
Dru
_____
1971 280SE "Beverly"
1990 250D 5-speed "Opa"
1995 E220T Sportline "Sportwagon"
1980 911SC Targa "Petrol"

Todd

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Re: W108 "Beverly" transmission leak questions
« Reply #6 on: August 04, 2022, 18:21:17 »
I completely understand their not wanting to get into something this old.  "We've" entered an era where customer's (I'm not saying you're this way) have become very difficult.  So shops are learning to cull those folks, by saying what you're being told.

It's been a long time since I was R&Ring placing automatic transmissions on MBZ, BMW, etc. so I'll offer a few suggestions.  Just bare in mind that I'm not the god of this stuff, and it's been a while for me.

I can't tell by your post, but it appears that you've removed the transmission, or someone else has removed it for you?  If so, when the transmission was removed, did the TC get left on the flex plate (flywheel)?  Or was the TC unbolted from the flex plate, and left on the transmission, securing it in place with wire, and then the transmission removed from the car?

Suggestions:

Lift the TC just slightly, and slide it off the input shaft in the transmission.

You will now see the TC seal (input shaft seal), and the area of the pump flange, etc.
Start by looking for the cleanest area of the leak zone, as mentioned.  This will be your leak source.

If the TC seal looks like it hasn't been leaking, you can test it for how flexible it still is, by taking a small, thin screwdriver, and gently pushing on the seal's inner lip.  If it seems to be really nice and flexible, and not cooked and stiff, that seal is probably still good.  You can take a rag and clean out the seal lip grooves, and re-grease it.   If the seal looks like it's been leaking, pry it out and replace it.  If you can't find the correct part number, the seal can be measured and replaced based on it's size.  It may have a part number stamped on it, or it may have it's metric size stamped on it (outside diameter, inside diameter, and thickness).  If you can't get the OEM seal, try to replace with one that's of a higher heat rated material, so that it won't get cooked hard by the hot fluid, and the heat of the TCl.  The cooking of the seals is the death of all automatics, whether an external seal like this, or the internal lip seals and o-rings.  That's why it's important to keep automatic transmissions as cool as possible, especially in hot climates, or hilly conditions, or when towing.  When the seals get cooked hard, and leak, the internal clutch packs stop getting sufficient hydraulic pressure to stay clamped tight.  The clutch packs then start to slip, which generates more heat, and frags the transmission with clutch friction disc, and metal plate debris...destroying the transmission very quickly.

Enough about the TC seal.

If you think the pump cover seal is leaking (gasket? o-ring?) and it looks like the cover can easily be removed, then definitely replace it.

When it's time to put the TC back on, you have to be really careful about not damaging the TC seal.  The splines inside the TC opening need to be centered in the opening, and kept that way during install.  The TC is gently slid on, and slightly rocked and rotated left and right, so that the splines all have a chance to move around and mate up, while you apply "some" installation pressure, to get the TC to drop into position fully.  You than pass wire, from one side of the bell housing to the other, over the front of the TC, in order to trap the TC against the transmission, so it can't slide forward, as I mentioned previously.  Sometimes the TC is easier to install with the transmission standing upright, and the TC dropped down onto the input shaft.  You can use the weight of the TC to help it fall down into place, but you also do a gentle lifting and rotating motion to get those splines to line up, and then you let the TC come downward and see if it will drop on it's own.  If it doesn't, you gently lift a little, and keep rocking it left and right, and then letting it drop again.  Once the splines are all lined up, it will drop down into place really easily.

Hopefully others who have much more experience/current experience, with chime in, and really help you out.
Todd

K-Jet

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Re: W108 "Beverly" transmission leak questions
« Reply #7 on: August 10, 2022, 09:08:40 »
Thank you, Todd and Joe. Here's 8 seconds of why I'm concerned about the input shaft. Is this normal, or are there more parts I should be searching for?

https://youtube.com/shorts/Q0yO9FAKFxQ
Dru
_____
1971 280SE "Beverly"
1990 250D 5-speed "Opa"
1995 E220T Sportline "Sportwagon"
1980 911SC Targa "Petrol"

Todd

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Re: W108 "Beverly" transmission leak questions
« Reply #8 on: August 10, 2022, 12:28:53 »
I wish I could tell you for sure, if that is okay, or if it isn't.  Here's what I think, and it's what I mentioned before:  When the TC is mounted on that input shaft, and the transmission is installed, and then the TC is bolted to the flex plate, there will be no more movement, because the flex plate is bolted to the crankshaft.
Todd

K-Jet

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Re: W108 "Beverly" transmission leak questions
« Reply #9 on: November 28, 2022, 15:06:23 »
Joe, Todd, and all,

Between document difficulties and other challenges, t has been a while. As always, there is good news and bad news.

The good news is that new seals have solved the leakage problem. The oil stays inside. The bad news is that when the transmission is warm and under duress (higher speed, uphill, or just too much throttle) the transmission will slip rather than transmit torque to the rear wheels. The brand new transmission oil is the .6 specification and is full to the line when warm and running (either in gear or out).

As a reminder, the car has been off the road for at least 10 years, so there's no telling what we'll keep finding!

So adjustment or wear or it just needs more miles?
Dru
_____
1971 280SE "Beverly"
1990 250D 5-speed "Opa"
1995 E220T Sportline "Sportwagon"
1980 911SC Targa "Petrol"

K-Jet

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Re: W108 "Beverly" transmission leak questions
« Reply #10 on: December 06, 2022, 16:48:46 »
So the big blue book says that a pressure deficiency can lead to overspending on the 3 to 4 shift. Does anyone have the pressure gauges, or has anyone made their own?
Dru
_____
1971 280SE "Beverly"
1990 250D 5-speed "Opa"
1995 E220T Sportline "Sportwagon"
1980 911SC Targa "Petrol"

ja17

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Re: W108 "Beverly" transmission leak questions
« Reply #11 on: December 06, 2022, 17:08:05 »
Too bad your so far away. I must have five or six good used transmissions for your car laying around here.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2006 Mercedes Sprinter Van
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback