300D Auto transmission interchangeability

1976-1985: 230T, 230E, 230TE, 230CE, 280E, 280TE, 280CE, 240D, 300D, 300CD, 300TD,
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3DB
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300D Auto transmission interchangeability

Post by 3DB » Tue 16 Jan, 2018 1:47 pm

Hi all,

I have a 1976 model 300D with a manual kick-down transmission and have been offered one of two spares (I assume both are vacuum kick-down):
  • One from a 1982 model 300D; and
  • Another from a 1984 model 300D.
Does anyone know off the top of their head whether either of these would make more sense in terms of easy interchangeability with my car?
3DB
1976 W123 300D (weekend warrior on biodiesel)
1995 Holden Rodeo 2.8 factory turbo diesel ute (daily driver...also on biodiesel)
(@thirddegreeburns on Instagram)

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Tony From West Oz
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Re: 300D Auto transmission interchangeability

Post by Tony From West Oz » Tue 16 Jan, 2018 7:03 pm

Both of these use a vacuum modulator. The '84 also uses an throttle position cable.
Your IP does not have a vacuum control valve (to supply vacuum to the transmission modulator.
These will make the installation of either of these transmissions problematic.
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (occasional tourer)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

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3DB
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Model you own: w123
Location: Sydney

Re: 300D Auto transmission interchangeability

Post by 3DB » Tue 16 Jan, 2018 10:49 pm

Thanks, Tony.

I did wonder about the vacuum modulator, but didn't realise the IP was different.

I also have a spare IP.....it is off a later car and looks slightly different. I recall that one is an 'M' pump and the other is an 'MW'.....not sure which is which and if it is even relevant. Also not sure if the spare IP is serviceable.

In theory, if I was to put a new trans in my car with the old IP, is it only kick-down that would be affected if no vacuum was applied, or all gear changes? Reason I ask is I find I manually shift a lot anyway (especially up and down between to 2nd & 3rd) as the shift points are sub-ideal and finicky when cold.
3DB
1976 W123 300D (weekend warrior on biodiesel)
1995 Holden Rodeo 2.8 factory turbo diesel ute (daily driver...also on biodiesel)
(@thirddegreeburns on Instagram)

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Tony From West Oz
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Re: 300D Auto transmission interchangeability

Post by Tony From West Oz » Wed 17 Jan, 2018 2:39 am

Without the vacuum supply to the modulator the engine would rev out very high before up shifting and shifts would be harsh.
You could apply full vacuum to the modulator, but then shifts would be soon and very soft. In fact, if you were trying to accelerate a 300D in traffic the tranny would most likely slip significantly during shifting and your acceleration would be even slower than was before. I suppose you could use a vacuum restriction and a valve set to leak vacuum off, so you could adjust the vacuum for a compromise between transmission acceleration and shift points.
If that sounds OK they I would recommend the '80 - '83 transmission rather then the '84 one.
How much are they asking for the transmissions:?
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (occasional tourer)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

tsharkey
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Re: 300D Auto transmission interchangeability

Post by tsharkey » Wed 17 Jan, 2018 11:06 am

Hi Ethan,
Everything Tony said plus ,,,,,

You can fit the vacuum modulator onto the side of the IP and you will have to get the throttle linkages for the top of the valve cover. All quite doable but there is a bit of fine tuning.

If you fitted the late IP, you will need the Injector lines as well as the later IP is smaller and closer to the engine. You will also need to block off the oil return between the block and IP as the later doesn't use it. Once again, all doable but with some complexity.

Interestingly, the Factory Turbo diesels use the early style IP through out.

I am not 100% sure if the transmissions themselves are the same length - so a tailshaft revision might be required. It may also trigger a different rear cross member that the gear box bolts onto and different NeutralStart / Reverse Light wiring requirements and speedo cable length ....

If you had access to the donor car with all the minor bits - Then you would be OK. Without, inevitably you will get into the I need to source / adapt incremental upgrade game as you are doing the job .....

The later transmissions are oK but are notorious for developing very weak reverse. You tighten the band till there is no more and then still loose reverse when the trans is cold. That plus flaring over time and leaking rear seal. This developed on the family wagon, so I had the trans fully reco'ed by a workshop that only does transmissions and when I rang them, they could immediately tell me the various flavours of auto's the W123 had (as Tony listed above) and their common problems (demonstrating they had the right knowledge beyond transmissions themselves).

It cost about $1,500 turn key (I drove in and they did the job - Got the car back a week later).
W123 1981 300TD - Family Kid mover
W202 1998 C250D Factory OM605A Turbo - Partner's daily driver
W123 1982 300CD Retro fitted OM617A Turbo - Mine
W123 1984 300TD 5 Speed Manual, to teach the kids how to drive
W123 1982 300TD Factory OM617A Turbo (Hans) - Project
W123 1985 230TE - Brother's
W123 1985 300D - Sister in Law's
1962 S-Series Valiant (Tho Daimler & Chrysler divorced, still part of the extended family)

Past benzes
W114 1969 250CE - PO put in an M110 transplant and nearly sent me around the bend
W123 1981 300TD - "Matilda" - RIP hit front side & rear but left my brother + niece A-OK

Current Projects
Coupe restoration, Turbo Wagon freshen up

mathuisella
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Re: 300D Auto transmission interchangeability

Post by mathuisella » Wed 17 Jan, 2018 11:10 am

:) the transmissions are mine, i'm moving house and my car is manual transmission, so i offered one to 3DB. I don't want much, just make me an offer that's fair :) otherwise they'll sit in the garage wrapped up at the new place.

location brisbane :)

1984 transmission
26855009_10213100679284416_942508506_o.jpg

1982 transmission
26942131_10213100679364418_1825528988_o.jpg
all covered in the corner of the garage protected from the elements
26942002_10213100696324842_738458128_o.jpg
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tsharkey
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Re: 300D Auto transmission interchangeability

Post by tsharkey » Wed 17 Jan, 2018 2:23 pm

mathuisella wrote:
Wed 17 Jan, 2018 11:10 am
:) the transmissions are mine, i'm moving house and my car is manual transmission, so i offered one to 3DB.
I think 3DB would want an upgrade kit that includes

1. Vacuum regulator that connects to the side of the IP
2. The Vacuum valves and hoses that connect to the accelerator lingages, the IP Vacuum regulator and transmission

Are they different lengths ? Get 3DB to measure his as well.

The 84 would be the best as I suspect it is common to the M110 version as well and is the strongest (her has a turbo so the upgrade is worth it). Stamped on the side of the 84 will be a number 1232711901722xxx - What is the XXX ? that will spell out which series transmission it actually is, I couldn't get it off Google but the 123 271 19 01 was fitted to Turbo Diesels in the US.
W123 1981 300TD - Family Kid mover
W202 1998 C250D Factory OM605A Turbo - Partner's daily driver
W123 1982 300CD Retro fitted OM617A Turbo - Mine
W123 1984 300TD 5 Speed Manual, to teach the kids how to drive
W123 1982 300TD Factory OM617A Turbo (Hans) - Project
W123 1985 230TE - Brother's
W123 1985 300D - Sister in Law's
1962 S-Series Valiant (Tho Daimler & Chrysler divorced, still part of the extended family)

Past benzes
W114 1969 250CE - PO put in an M110 transplant and nearly sent me around the bend
W123 1981 300TD - "Matilda" - RIP hit front side & rear but left my brother + niece A-OK

Current Projects
Coupe restoration, Turbo Wagon freshen up

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3DB
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Model you own: w123
Location: Sydney

Re: 300D Auto transmission interchangeability

Post by 3DB » Wed 17 Jan, 2018 5:50 pm

Crikey, nothing is ever simple is it?

Thanks for all the good knowledge there.

Tim - my ears pricked up a bit when you said the factory turbodiesels use the old IP......off the topic here, but is the ALDA unit on those a modular part that bolts on? Or do you need a completely different IP with factory ALDA?

(another way that I can increase power and break the trans faster)
3DB
1976 W123 300D (weekend warrior on biodiesel)
1995 Holden Rodeo 2.8 factory turbo diesel ute (daily driver...also on biodiesel)
(@thirddegreeburns on Instagram)

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GrampiansMerc
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Re: 300D Auto transmission interchangeability

Post by GrampiansMerc » Fri 19 Jan, 2018 5:00 pm

Hey there 3DB

for your information I put a trans from a 280 (petrol) in my 300TD (diesel) it changed better and perked it up a bit!
1980 300TD "Anna" - 400,000kms and still cruising, converted to SVO
1979 300D - sold, gone to be restored
1980 300D - "Lightning" recently purchased and currently making repairs
2006 Musso - Korean Mercedes, 5 cylinder diesel - Blown head gasket, buggered motor, grrrrrrr (I will stick with German Mercs)
Looking for 300GD LWB five door!
http://www.overlander300td.wordpress.com/

I'm just a simple man trying to make my way in the universe

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Tony From West Oz
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Re: 300D Auto transmission interchangeability

Post by Tony From West Oz » Fri 19 Jan, 2018 10:37 pm

3DB wrote:
Wed 17 Jan, 2018 5:50 pm
Crikey, nothing is ever simple is it?

Thanks for all the good knowledge there.

Tim - my ears pricked up a bit when you said the factory turbodiesels use the old IP......off the topic here, but is the ALDA unit on those a modular part that bolts on? Or do you need a completely different IP with factory ALDA?

(another way that I can increase power and break the trans faster)
3DB, While the IPs are from the same series, they are different inside the housing. The ALDA acts on the Max Fuel adjustment to increase fuel on boost (or reduce fuel on a NA engine at altitude). The old style IPs I have seen in Australia (other than ones for a turbodiesel) did not have an ALDA fitted (probably because MB didn't believe we had any significant traffic at high altitudes.

I can provide you with photos explaining how to increase the Max Fuel adjustment, if you want to increase the power of your engine. You should easily get 10%, maybe 20% increase at the expense of fuel economy and increased black smoke.
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (occasional tourer)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

mathuisella
Adenauer
Posts: 383
Joined: Sun 08 Jun, 2014 7:03 am
Model you own: w123
Location: Brisbane, North side.

Re: 300D Auto transmission interchangeability

Post by mathuisella » Mon 22 Jan, 2018 4:46 am

viewtopic.php?f=20&t=24690

put the two transmissions up for sale, $100 each :) come grab a bargain for in 10 years time you'll be kicking yourself when the tranny blows and the cheapest replacement is north of $1000

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3DB
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Re: 300D Auto transmission interchangeability

Post by 3DB » Thu 25 Jan, 2018 3:44 pm

Tony From West Oz wrote:
Fri 19 Jan, 2018 10:37 pm
I can provide you with photos explaining how to increase the Max Fuel adjustment, if you want to increase the power of your engine. You should easily get 10%, maybe 20% increase at the expense of fuel economy and increased black smoke.
Thanks, Tony - I'd be grateful to receive that information.
3DB
1976 W123 300D (weekend warrior on biodiesel)
1995 Holden Rodeo 2.8 factory turbo diesel ute (daily driver...also on biodiesel)
(@thirddegreeburns on Instagram)

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Tony From West Oz
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Posts: 3174
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Re: 300D Auto transmission interchangeability

Post by Tony From West Oz » Thu 25 Jan, 2018 5:52 pm

3DB,
I posted in the relevant section - The Mod Squad (not sure if this is accurate for a NA 300D LOL)
viewtopic.php?f=30&t=24706
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (occasional tourer)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

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