280 SL 4 Speed transmission

[leitz 280 sl]

I looked under my 1970 280SL car after being gone for two weeks and find a pool of Transmission fluid.  Since my car is a 4 Speed and it does use ATF and not a conventional maunal transmission oil I am certain I have a leaking seal. Now this translates into pulling the transmission and bell housing and checking the seals.  Does anyone have any good advice before I start this project.  Does anyone know where I could get another 4 speed to rebuild before I pull my original?  Any advice would be appreciated.  If it could possibly be any other problem besides leaking seals I would appreciate the benifit of someone elses experience as well.

Bill Owen
1970 280 SL 4 speed.
American version.

[ja17]

Hello Bill,

Replacing the transmission seals does not require a total tear down. Unless you have other transmission issues you may just want to replace the seals and gaskets and re-instll it.  Make sure the transmission is not overfilled to start with.

Joe Alexander
Blacklick, Ohio

[mchokhdar]

hey guys, i have a 1969 SL 280 that is automatic with a 4 speed transmission. when I am driving 60 MPH,  the RPM reads 3000. but when i am driving 80 MPH, the RPM goes over 4000. is this normal in such cars to have? will it make an impact or an overload on the engine? can the transmission be changed to a 5 speed? is it worth it? what speed and RPM reading you recommend on a highway with this car?

thanks

[JamesL]

That's normal. Depending on the rear axle but the engine was built to rev and run at high reves for long periods. So 3000/60 is about right give or take

5 speed Auto is a tough one. There was an optional ZF 5 speed manual but the only auto I have come across is from Stickel in Germany and mucho expensive... (and not a period option)

Yours is a 4 speed but for 98% of the time is a 3 speed !

[mchokhdar]

Thank you for your quick response, so is it okay to drive for a long period of time with  80 MPH and the RPM reading 4500.

[49er]

Thank you for your quick response, so is it okay to drive for a long period of time with  80 MPH and the RPM reading 4500.

 Might want to keep an eye out for the CHP in your rear view mirror. They kind of frown on that sort of thing. Now if you lived in Germany, no problem:-)

John

[mchokhdar]

that is true John, but driving at such a speed and the RPM that high, does it affect the engine or the car, what speed do you recommend on a highway

[ja17]

Mercedes engines are very durable if they are healthy and well maintained.   They are designed to run at max rpms for extended periods of time.
If y our engine is healthy, you can run at any rpm below red line. The busy engine will become music to your ears as time goes on and your confidence increases.

[mchokhdar]

now i just have to get used that since i have never had a classic mercedes benz before, any ideas about where i can get hard copy duplicates of any documentations, i would love to get them for reference, i will also be willing to get these documentations, and also where can i get some rare parts for it? like the Snowflake decal?

[ja17]

The Mercedes-Benz Classic Center is a good place to start. They are on line or in Irvine California

[WillS]

Another option you can go with is replacing your short-legged rear axle with a bolt-in longer-legged one like the 3.27 axle out of a 280SEL 4.5L sedan. I did that with my 4sp 280SL and love it. The only work I had to do was remove and plug off the cooling tube holes and replace the seals. Yes, the engine can handle the high revs for long periods, but I like the relaxed cruising ability given by the 3.27.

hey guys, i have a 1969 SL 280 that is automatic with a 4 speed transmission. when I am driving 60 MPH,  the RPM reads 3000. but when i am driving 80 MPH, the RPM goes over 4000. is this normal in such cars to have? will it make an impact or an overload on the engine? can the transmission be changed to a 5 speed? is it worth it? what speed and RPM reading you recommend on a highway with this car?

thanks