Transmission swap options - PeachParts Mercedes-Benz Forum

danielevioli · #1 06-19-2017, 06:03 PM

I've decided i need to put in a different transmission. The car is an 81 300d, turbo diesel. The transmission is 722.118, and only vacuum controlled. I see conflicting information on the internet... Is this the stock tranny?

Is the 118 also the only option I have? I imagine its the only only-vacuum-controlled model out there?

Frank Reiner · #2 06-19-2017, 06:11 PM

Consider using a 722.3xx from a 300SD, or from later turbo 123s.

diesellover 92 · #3 06-19-2017, 09:54 PM

there is a bellhousing kit to swap in a chevy 700r4. Much better trans in every way.

Frank Reiner · #4 06-19-2017, 10:22 PM

Quote:

Originally Posted by diesellover 92

there is a bellhousing kit to swap in a chevy 700r4. Much better trans in every way.

Link?

Partscarver · #5 06-19-2017, 10:52 PM

Mercedes diesel info

ROLLGUY · #6 06-19-2017, 11:31 PM

Quote:

Originally Posted by danielevioli

I've decided i need to put in a different transmission. The car is an 81 300d, turbo diesel. The transmission is 722.118, and only vacuum controlled. I see conflicting information on the internet... Is this the stock tranny?

Is the 118 also the only option I have? I imagine its the only only-vacuum-controlled model out there?

I could be wrong, but I don't believe a turbo engine came from the factory in a '81 sedan. It could have been swapped in. Or turbo manifolds (and other needed mods) could have been put on the N/A block. The 722.1XX is the correct trans for that year.

Quote:

Frank Reiner
Consider using a 722.3xx from a 300SD, or from later turbo 123s.

The SD trans has a different tail cone, and electric speedo. A 722.3 from 1982-1985 (sedan or coupe) will work. You will need all the linkage and mechanical's from the top of the valve cover for the control cable. The neutral safety switch wiring connector is different as well.

dkr · #7 06-20-2017, 01:57 AM

Quote:

I could be wrong, but I don't believe a turbo engine came from the factory in a '81 sedan. It could have been swapped in. Or turbo manifolds (and other needed mods) could have been put on the N/A block. The 722.1XX is the correct trans for that year.

I'm pretty sure 1982 was the first turbocharged year for the 300Ds. The 300SDs had the turbocharged setup going back earlier.

Dkr.

ROLLGUY · #8 06-20-2017, 09:42 AM

Quote:

Originally Posted by dkr

I'm pretty sure 1982 was the first turbocharged year for the 300Ds. The 300SDs had the turbocharged setup going back earlier.

Dkr.

1978 in the W116, 1981 for the W126. 300TD's got the turbo in 1981. These are all for American market. Other countries might have gotten them sooner/later.

t walgamuth · #9 06-20-2017, 10:41 AM

Seems the coupe might have gotten a turbo motor a year early from the sedans and wagons...?

ROLLGUY · #10 06-20-2017, 11:14 AM

Quote:

Originally Posted by t walgamuth

Seems the coupe might have gotten a turbo motor a year early from the sedans and wagons...?

I've had both an '81 and '82 coupe, and the '81 was N/A, '82 was turbo. Only the wagon variant of the W123 got the turbo in '81.

danielevioli · #11 06-20-2017, 02:14 PM

Yeah... seems strange.. rare model or modded over time? It doesn't just have a turbo.. it says 300d - turbo diesel on the back...

I'm going to drop it off at a trustworthy competent mechanic thursday and he's gonna take a look at the controls and diagnose the tranny.

Quote:

Originally Posted by ROLLGUY

A 722.3 from 1982-1985 (sedan or coupe) will work. You will need all the linkage and mechanical's from the top of the valve cover for the control cable. The neutral safety switch wiring connector is different as well.

Can anyone confirm this? You say sedan or coupe... you mean any 300D or any model sedan or coupe of those years, turbo or N/A? Also.. whats the neutral safety switch and how crucial is it? I noticed that I do have a wire that's just hanging down there near the modulator... looks like it should plug into something near the modulator...

ROLLGUY · #12 06-20-2017, 02:34 PM

Quote:

Originally Posted by danielevioli

Yeah... seems strange.. rare model or modded over time? It doesn't just have a turbo.. it says 300d - turbo diesel on the back...

I'm going to drop it off at a trustworthy competent mechanic thursday and he's gonna take a look at the controls and diagnose the tranny.

Can anyone confirm this? You say sedan or coupe... you mean any 300D or any model sedan or coupe of those years, turbo or N/A? Also.. whats the neutral safety switch and how crucial is it? I noticed that I do have a wire that's just hanging down there near the modulator... looks like it should plug into something near the modulator...

Yes, 300D or 300CD. Although the TD (Touring Diesel=wagon) should have the electric speedo like the W126 300SD, I have seen some cable driven. It may be that just one year was electric for the T, but I don't know for sure. Either way, any 722.3XX trans will work in your car that has a cable driven speedo.
There is a website somewhere that you can input the VIN, and it will give you all the factory specs for that car. It would be very interesting to see if it is in fact a factory original car. If so, it would be extremely rare, and should be kept as original as possible (in my opinion)......Rich

danielevioli · #13 06-20-2017, 02:58 PM

Quote:

Originally Posted by ROLLGUY

There is a website somewhere that you can input the VIN, and it will give you all the factory specs for that car. It would be very interesting to see if it is in fact a factory original car.

Any info about this database? I'd like to know more about the original specs for the car... would be very useful

Mxfrank · #14 06-20-2017, 03:14 PM

Quote:

Originally Posted by ROLLGUY

I could be wrong, but I don't believe a turbo engine came from the factory in a '81 sedan. It could have been swapped in. Or turbo manifolds (and other needed mods) could have been put on the N/A block. The 722.1XX is the correct trans for that year.

The SD trans has a different tail cone, and electric speedo. A 722.3 from 1982-1985 (sedan or coupe) will work. You will need all the linkage and mechanical's from the top of the valve cover for the control cable. The neutral safety switch wiring connector is different as well.

'81 was the first year for the turbo. Wasn't the starter motor moved from right to left between the 722.1 and 722.3? If so, they may not interchange.

ROLLGUY · #15 06-20-2017, 09:40 PM

Quote:

Originally Posted by Mxfrank

'81 was the first year for the turbo. Wasn't the starter motor moved from right to left between the 722.1 and 722.3? If so, they may not interchange.

Doing a little research, I found this on Wikipedia:
"North America and Japan

In these markets the following models were offered:^[7]

Model	Years	Engine	Power	Torque
230	MY 1977–1978	M115	93.0 hp (69 kW) @ 4800	125 lb·ft (169 N·m) @ 2500 (USA-Canada only )
240D	MY 1977–1983	OM616.912	62 hp (46 kW) @ 4000 from MY 1981 67 hp (50 kW) @ 4000	97 lb·ft (132 N·m) @ 2400 (USA-Canada only)
280E	MY 1977–1981	M110	142 hp (106 kW) @ 5750 from MY 1980: 140 hp (104 kW) @ 5500	149 lb·ft (202 N·m) @ 4600 from MY 1980: 145 lb·ft (197 N·m) @ 4600 (USA-Canada only)
280CE	MY 1978–1981	M110	142 hp (106 kW) @ 5750 from MY 1980: 140 hp (104 kW) @ 5500	149 lb·ft (202 N·m) @ 4600 from MY 1980: 145 lb·ft (197 N·m) @ 4600 (USA-Canada only)
300D	MY 1977–1981	OM617.912	77 hp (57 kW) @ 4000 from MY 1981: 83 hp (62 kW) @ 4200	115 lb·ft (156 N·m) @ 2400 from MY 1981: 120 lb·ft (163 N·m) @ 2400 (USA-Canada)
300CD	MY 1978–1981	OM617.912	77 hp (57 kW) @ 4000 from MY 1981: 83 hp (62 kW) @ 4200	115 lb·ft (156 N·m) @ 2400 from MY 1981: 120 lb·ft (163 N·m) @ 2400 (USA-Canada only)
300TD	MY 1979–1980	OM617.912	77 hp (57 kW) @ 4000	115 lb·ft (156 N·m) @ 2400 (USA-Canada only)
300D Turbo	MY 1981–1985	OM617.952	125 hp (93 kW) @ 4350	181 lb·ft (245 N·m) @ 2400 (USA-Canada, Japan only)
300CD Turbo	MY 1981–1985	OM617.952	125 hp (93 kW) @ 4350	181 lb·ft (245 N·m) @ 2400 (USA-Canada only)
300TD Turbo	MY 1981–1985	OM617.952	125 hp (93 kW) @ 4350	181 lb·ft (245 N·m) @ 2400 (USA-Canada only)

The naturally aspirated 300TD wagon only had a brief career in North America, being replaced by a turbocharged model for the 1981 model year. Most American buyers had found the heavy wagon much too slow with the less powerful engine.^[8] The turbodiesel engine also appeared in the sedan and coupé models in America, but only a few months behind the wagon. Manual transmissions were generally only available to North American buyers in the four-cylinder models, and a five-speed was never available. From 1982 until the W123's replacement in late 1985, only diesels were sold in North America. The federalized W123s differ from the European W123s due to United States Department of Transportation requirements."

If your engine is a 671.952, and does not look like it was changed from an N/A, then it may just be the real deal. It may be a late production 1981 year model ( "The turbodiesel engine also appeared in the sedan and coupé models in America, but only a few months behind the wagon." ), which would have the 671.952 according to Wikipedia. Every other 1981 W123 sedan or coupe that I have seen (I have seen MANY), has had the 617.912 (N/A).

Mxfrank: All 61X engines (iron head up to 1985) have the starter on the right side. All 60X engines (aluminum head) have the starter on the left.

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