The amazing 3 speed automatic transmission
 

Just finished rebuilding, installing, and adjusting a 3 speed automatic, in an early 4.5 liter car.
https://cimg2.ibsrv.net/gimg/rennlis...4d4713e62f.jpg
3 speed automatic, rebuilt and ready to install.

And wanted to mention how magnificent these transmissions function, when internally proper and adjusted correctly, in these early cars.
They upshift and downshift through the gears virtually without a flaw....completely dependent upon what you ask the car to do.
Almost like they are connected to your thoughts and desires...

Yes, I also enjoy the 5 speed cars (I enjoy just about every 928 model)....but I'm not convinced that converting an automatic to a 5 speed is the best ever "upgrade" to do.
Frankly, I'm a bit surprised that I can't ever remember someone going the other way....5 speed to an automatic.

https://cimg0.ibsrv.net/gimg/rennlis...c660bbdbd.jpeg

I always thought the 3 speed was the better trans. Even gear spacing and shifts effortlessly when asked.

It was better in my 81 than the 4 speed in my 89 S4 from my own experience.

Which ones do you not enjoy? I guess 82-85 US

Those of us with 3-speed RoW cars know how pleasant of a transmission they really are. Fantastic box, and much stronger than the later 4-speed unit. If it were a choice between all three transmission options in the earlier cars I would only really consider the 3-speed or the 5-speed stick.

Sorry to ask a question on your thread but I have been asking about the adjustment on these boxes as I have an 83 in the uk and hoping the cable just needs adjusting as it doesn’t want to change up unless I back off the gas slightly.
I can only find information on the later box adjustment.
Thanks in advance.

Nice tower for the gearbox!:)
Should not to difficult to build it myshelf

Hear Hear! Agree completely! Very happy with mine.
jp 83 Euro S AT 57k mi

What RPMs do the 3 speed boxes turn at 90 mph? I would guess the 4 speeds have a better gear ratio for high speed cruising at a lower rpm. My 4 speed 84 Euro S turns 2,800 rpm at 90 which is where it's driven most of the time on trips. It also starts in 1st gear which I guess some of the later 4 speeds don't.

The 3 speeds are almost bulletproof.....275K on the one in the 79 928 and 600k on the one in the 84 MB 300DT.Neither have been rebuilt,just fluids changed and leaks fixed.

Yes, factory tool. Not very common. This one was found and belongs to Rob Edwards. I just make sure it gets used....

If you need more details, i can send yiu more pictures/measurements.

The Workshop Manual covers this.
To start, you set the ball socket at the kickdown lever so that it fits directly onto the ball (no throttle applied) without preload or slack. You can adjust the ball or the lever to accomplish this.
When correct, from idle to full throttle, the level needs to move 33 milimeters.

Amazingly robust, until rebuilt by one of the "flat rate/one price" rebuilders. They don't last very long, when redone with poor quality parts and poor quality labor. Unfortately, the conbination of these two things generally "kills" expensive factory only internal parts.

And like all things Porsche/Mecedes, factory parts have gotten very expensive.

Many thanks, I couldn’t find it in the WM. Will look again.

Workshop Manual, Volume II. Page 37-14.
Fairly vague, since they don't tell you when to measure, where to measure, and how to measure, like I did, above.