What is the difference between the 4 speed 722.4 and the 5 speed 722.5 (besides one gear) Durability, Reliability? If I had an opportunity to put a five speed in a 300SDL would this work out well or be discouraged?

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Don Martin
Bakersfield, CA
87 300SDL

I am assuming the 722.5 is the new "sealed for life" trans found in the 1997+ W210s. I assumed it was used even in the W211's until the new 7spd comes out.

Both are very reliable long lived trans, and are capible of 300k miles. However the 5spd requires special fluid, filter, and tool to change the fluid. So it really is a dealer only thing, but it only runs about $180. Since you only have to do it every 80k miles or so it isn't to bad.

Putting a 5spd into an SDL would be a monster project, and would probably require a few custom parts. Also it is computer controlled so you will need to bring all of those along.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

The 722.5 was basically a 722.4 with an electronically controlled overdrive 5th gear. It's not at all related to a 722.6.

It was widely available in Europe but I think it was only offered in the US in 6 cylinder W140 chassis and the W129 SL.

I know the 722.6 is sealed for life but I thought the 722.5 wasn't?

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01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

722.6 is the more common trans in most of the newer MB's.

the 722.9 is the new 7-speed. The new ML has it, and no shift linkage... all electronic with a noisy actuator motor to boot.. I cant wait untill I get one of these to fix

one more thing, sealed for life?? LMAO! Please don't believe that.

the fluid is brown before you hit 50,000 miles! change it! 722.6 are KNOWN for leaking their fluid at the electrical connector (connector has since been modified to correct the leak), keep an eye on it for those of you with these transmissions! I've had to replace two in the last two months that were run dry cause these things were leaking.

Kinda sad really, new 2005 cars with less than 1000 miles on them coming in because there was red fluid pooling in the new owners driveway. The older ones seem to hold up better.

New connector has a 203 part number, the old ones have a 140 number. You can modify the 140's to fix the leaking, just replace the two seals when you do.

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1980 500SE/AMG Euro
1981 500SEL Euro
1982 380SEL
1983 300TD
1983 500SEC/AMG Euro
1984 500SEC
1984 300TD Euro
1986 190E 2.3-16
1986 190E 2.3
1987 300D
1997 C36 AMG
2003 C320T 4matic

past: 1969 280SE 4.5 | 1978 240D | 1978 300D | 1981 300SD | 1981 300SD | 1982 300CD | 1983 300CD | 1983 300SD | 1983 380SEC | 1984 300D | 1984 300D | 1984 300TD | 1984 500SEL | 1984 300SD | 1985 300D | 1986 300E | 1986 560SEL | 1986 560SEL/Carat | 1987 560SEC | 1991 300D 2.5 | 2006 R350