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240d with om605 swap in progress
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Discussion Starter · #1 ·
Hiya from Glasgow (so these cars are RHD),

I'm sure this has been done before. I've looked around forums like super turbo diesel for specific info but have come up short.

Basically I've got 2 cars: W123 om616 240d with the 4 speed manual, and a W202 C250 with the OM605 and 5 speed automatic transmission. Both running and in decent condition.

The om605 is going in the W123 and I'm just deciding on keeping the manual or swapping the automatic as well. I'd prefer the manual, but if it's easier to swap the engine and transmission together I'd do that.

If you know of a thread or a person who's done this and can point me in their direction that would be ace. I know this is not just plug and play. There will be lots of fiddly bits to get everything sorted, but my hope is to keep this car as long as the sun continues to come up in the morning, maybe even convert it someday to (gasp) an electric motor from a Tesla or something.

I am planning on using Baldur's DSL1 controller for the swap, as that will handle most of the electronic gizmos as I'm keeping the EDC/electronic fuel pump (mostly because I have 2 of them although would prefer mechanical pump) and am committed to adding cruise control to the w123.

Cheers,
Jon
 

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1982 300CD; 2012 ML350 BT; 2011 E350 4M Wagon
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That would be a nice swap. It's always nice to hear about W123s being kept on the road.

At first glance, it looks like the 605 starter is on the left side of the motor. It's on the right of the 616. That could be your answer to the transmission question.

FB
 

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Hiya from Glasgow (so these cars are RHD),

I'm sure this has been done before. I've looked around forums like super turbo diesel for specific info but have come up short.

Basically I've got 2 cars: W123 om616 240d with the 4 speed manual, and a W202 C250 with the OM605 and 5 speed automatic transmission. Both running and in decent condition.

The om605 is going in the W123 and I'm just deciding on keeping the manual or swapping the automatic as well. I'd prefer the manual, but if it's easier to swap the engine and transmission together I'd do that.

If you know of a thread or a person who's done this and can point me in their direction that would be ace. I know this is not just plug and play. There will be lots of fiddly bits to get everything sorted, but my hope is to keep this car as long as the sun continues to come up in the morning, maybe even convert it someday to (gasp) an electric motor from a Tesla or something.

I am planning on using Baldur's DSL1 controller for the swap, as that will handle most of the electronic gizmos as I'm keeping the EDC/electronic fuel pump (mostly because I have 2 of them although would prefer mechanical pump) and am committed to adding cruise control to the w123.

Cheers,
Jon
the 240d is the best of all , very fixable , the other not .why would you introduce a cancer into a perfect car .
 

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W123 300CD, W123 300TD, W202 C250D Turbo
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I had once investigated the swap.

You need
  1. Engine arms off an OM602 W124 and add spacers to get the length right
  2. Mechanical injection pump from an OM602 Turbo (to get the ALSA) - Although you are going to wire the electronic pump with an aftermarket sensor ?
  3. Throttle position sensor (needed for the trans as well)
  4. An ECU for the 722.6xx trans - there is a guy in Denmark who has programmed one (ofgear.dk) - Note that Buldurs controller will interface with it and share TPS etc
  5. Electronic to mechanical converter for your speedo
  6. Custom rear cross mount for the back of the trans
  7. Tailshaft mod for FlexPlate and length
  8. GP Relay etc
You could fit a 722.3xx from an OM602/3 etc if you want to avoid all the trans teething issues tho a 722.6xx has overdrive and torque lockup so is much more economical

Good luck and keep us posted as I still may do it one day (and I have an OM605 plus the arms and IP)
 

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240d with om605 swap in progress
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126 Posts
Discussion Starter · #6 ·
I had once investigated the swap.

You need
  1. Engine arms off an OM602 W124 and add spacers to get the length right
  2. Mechanical injection pump from an OM602 Turbo (to get the ALSA) - Although you are going to wire the electronic pump with an aftermarket sensor ?
  3. Throttle position sensor (needed for the trans as well)
  4. An ECU for the 722.6xx trans - there is a guy in Denmark who has programmed one (ofgear.dk) - Note that Buldurs controller will interface with it and share TPS etc
  5. Electronic to mechanical converter for your speedo
  6. Custom rear cross mount for the back of the trans
  7. Tailshaft mod for FlexPlate and length
  8. GP Relay etc
You could fit a 722.3xx from an OM602/3 etc if you want to avoid all the trans teething issues tho a 722.6xx has overdrive and torque lockup so is much more economical

Good luck and keep us posted as I still may do it one day (and I have an OM605 plus the arms and IP)
BLESS YOU!!!! This is EXACTLY what I've been looking for.

I've read over Baldur's very well written, 'plain English' guide to the DSL1 controller and pretty much understand. I'm in touch w him and have been asking questions like crazy.

Re: #4 above, I thought the DSL1 handled this? I did look at the ofgear site and watched the video. Pretty damn amazing.

I'll assume #7 is readily available info via a search.

Any idea if I could just use a manual trans from a W202? They're relatively inexpensive used.

Or any way I could get an adapter to keep the 4speed in the W123 and avoid changing the driveshaft/s?

Thanks again!
 

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W123 300CD, W123 300TD, W202 C250D Turbo
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There is a page on the site PlaneCrazy provided that shows the W124 engine mounts and the holes made. Its in the video, well worth watching.

Yes, you can use a W202 manual trans - In fact the OM605 will bolt up to any manual from W201, W124 etc as the starter is on the other side than the OM617. In the UK there are a gazillion of them. Would say an adaptor plate for your OM606 Manual Trans is not available given the starter location. That said, who knows, somewhere in the world someone may have produced one. You would be better placed selling the manual trans, flywheel etc to one of our North American cousins who wants their W123 to be a "stick shift" - a W202 5 Speed would be much cheaper to secure.

The DSL1 doesn't manage the 722.6xx trans, you need the Ofgear Controller. Baldur appears to have interfaced it with the Ofgear so that they can share the same sensors (Throttle position, engine revs and speed) - The DSL1 passes this data to the Ofgear. Given Baldur is just a bit north of you, you could probably nip up to have a look at the actual install etc and bring one home.

For the rear mount, it's a matter of fitting the engine / trans and then dimensioning how and where the rear cross member fits. You would also measure how much of the tail shaft needs to be cut.
 

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240d with om605 swap in progress
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126 Posts
Discussion Starter · #9 ·
I had once investigated the swap.

You need
  1. Engine arms off an OM602 W124 and add spacers to get the length right
  2. Mechanical injection pump from an OM602 Turbo (to get the ALSA) - Although you are going to wire the electronic pump with an aftermarket sensor ?
  3. Throttle position sensor (needed for the trans as well)
  4. An ECU for the 722.6xx trans - there is a guy in Denmark who has programmed one (ofgear.dk) - Note that Buldurs controller will interface with it and share TPS etc
  5. Electronic to mechanical converter for your speedo
  6. Custom rear cross mount for the back of the trans
  7. Tailshaft mod for FlexPlate and length
  8. GP Relay etc
You could fit a 722.3xx from an OM602/3 etc if you want to avoid all the trans teething issues tho a 722.6xx has overdrive and torque lockup so is much more economical

Good luck and keep us posted as I still may do it one day (and I have an OM605 plus the arms and IP)
Is it om602 or om603 arms? I've seen both mentioned for this.

Also do I need to find space for the intercooler? And obviously a different radiator and electric fan & controllers....
 

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240d with om605 swap in progress
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Discussion Starter · #10 ·
There is a page on the site PlaneCrazy provided that shows the W124 engine mounts and the holes made. Its in the video, well worth watching.

Yes, you can use a W202 manual trans - In fact the OM605 will bolt up to any manual from W201, W124 etc as the starter is on the other side than the OM617. In the UK there are a gazillion of them. Would say an adaptor plate for your OM606 Manual Trans is not available given the starter location. That said, who knows, somewhere in the world someone may have produced one. You would be better placed selling the manual trans, flywheel etc to one of our North American cousins who wants their W123 to be a "stick shift" - a W202 5 Speed would be much cheaper to secure.

The DSL1 doesn't manage the 722.6xx trans, you need the Ofgear Controller. Baldur appears to have interfaced it with the Ofgear so that they can share the same sensors (Throttle position, engine revs and speed) - The DSL1 passes this data to the Ofgear. Given Baldur is just a bit north of you, you could probably nip up to have a look at the actual install etc and bring one home.

For the rear mount, it's a matter of fitting the engine / trans and then dimensioning how and where the rear cross member fits. You would also measure how much of the tail shaft needs to be cut.
Sorry for the flurry of posts.

So, if I went with the manual trans from W202/124/201, I could avoid spending £700 on the ofgear? I can get a 202 5 speed from N Ireland for £300 and sell the 722.6 autobox. That would be great and I'd prefer the manual anyways.

And I'll be selling the OM616 (213k miles) AND the 4 speed. I'm going through it now replacing fuel lines & filters and will do a compression test and adjust the valves before putting it on the market. Hopefully that will be a selling point, assuming it's not a POS.
 

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240d with om605 swap in progress
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Discussion Starter · #11 ·
There is also a 6 speed box from an SLK that might work. Not sure if it bolts to the 605 though. I saw one on fleabay for not too much £££
 

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W123 300CD, W123 300TD, W202 C250D Turbo
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It's pure dead brilliant what you are trying to achieve ....

Is it om602 or om603 arms? I've seen both mentioned for this.
OM602 as the 5 cylinder block is similar. OM603 if you were fitting and OM606 .....

So, if I went with the manual trans from W202/124/201, I could avoid spending £700 on the ofgear? I can get a 202 5 speed from N Ireland for £300 and sell the 722.6 autobox. That would be great and I'd prefer the manual anyways.
Yes - Make sure you get the shifter and and fly wheel etc. Also make sure you like balance manual flywheel to auto flywheel you remove.

And I'll be selling the OM616 (213k miles) AND the 4 speed. I'm going through it now replacing fuel lines & filters and will do a compression test and adjust the valves before putting it on the market. Hopefully that will be a selling point, assuming it's not a POS.
Would be an even bigger advantage if you can sell it running in the car and then remove for the buyer .... Not sure if there are too many buyers of 240D engines up you way.


Keep us updated on your gallus endeavour
 

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'86 W123 200, OM617 non-turbo, bastard 5-speed; '95 W202 C250 Diesel, OM605 non-turbo, 5-spd man
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Just remember that the W202 transmission doesn't have a speedo drive, neither mechanical nor electric. W124 or W201 transmission is preferable.
 
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Just remember that the W202 transmission doesn't have a speedo drive, neither mechanical nor electric. W124 or W201 transmission is preferable.
You are right - The electric speedo gets them all the time, I have seen people just use a GPS replacement but I am old school - want that sweeping needle on the dial. You get the speed signal from the DSL1 rather than off the tail cone of the trans - In fact reading the DSL1 manual suggests it will allow you to adjust the pulsing to suit the speedo (so you can get any speedo regardless of the diff ration you use ). #5 above suggests a manual converter for the speedo as I am yet to find an electric convert for the W123 cluster (the W126 / 124 are a different shape at the facia).
 

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'86 W123 200, OM617 non-turbo, bastard 5-speed; '95 W202 C250 Diesel, OM605 non-turbo, 5-spd man
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In that case, check out frans-c's thread on converting a W126 speedo to a W123:

My w126 to w123 speedo conversion

I don't know what a DSL1 is, but boy if I could mate a 6-speed manual and a 2.88 diff to my OM617...
 
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240d with om605 swap in progress
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Discussion Starter · #16 ·
Just remember that the W202 transmission doesn't have a speedo drive, neither mechanical nor electric. W124 or W201 transmission is preferable.
I had no idea about that, thank you kindly!

I'm not 100% sure what that is, but will assume it sends a message from the transmission to the speedo gauge about how fast you're travelling?!

The 240 also has no tachometer...just thought of that. I could get a BIG HUGE AMERICAN one from Summit Racing like drag racers use, and screw it to the dash.

No, that's a terrible idea. Something that looks nice is much preferred.
 

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240d with om605 swap in progress
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Discussion Starter · #17 ·
In that case, check out frans-c's thread on converting a W126 speedo to a W123:

My w126 to w123 speedo conversion

I don't know what a DSL1 is, but boy if I could mate a 6-speed manual and a 2.88 diff to my OM617...
You could do 85mph at like 1700 rpms or something nice and quiet like that.

DSL1 is an electronic controller to
swap newer engines into other vehicles. Won't paste the link here but a google search will find it.

I'll check out that thread, ta.
 

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240d with om605 swap in progress
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Discussion Starter · #18 ·
You are right - The electric speedo gets them all the time, I have seen people just use a GPS replacement but I am old school - want that sweeping needle on the dial. You get the speed signal from the DSL1 rather than off the tail cone of the trans - In fact reading the DSL1 manual suggests it will allow you to adjust the pulsing to suit the speedo (so you can get any speedo regardless of the diff ration you use ). #5 above suggests a manual converter for the speedo as I am yet to find an electric convert for the W123 cluster (the W126 / 124 are a different shape at the facia).
So what's the 'easiest' way to keep the odometer correct-ish? I'm not bothered by the speedo not working...but not having a tach is problematic...hmmmm....and I'm not fussed if it's not the OEM cluster. I just want to know what the car is telling me but not worried about the platform/delivery of said info. Also will be adding boost and EGT gauges (and water injection). Perhaps if Baldur's and OFgear's devices can provide all that info it would be worth the (gulp) £1200, and avoid purchasing mechanical gauges.
 

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240d with om605 swap in progress
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126 Posts
Discussion Starter · #19 · (Edited)
I had once investigated the swap.

You need
  1. Engine arms off an OM602 W124 and add spacers to get the length right
  2. Mechanical injection pump from an OM602 Turbo (to get the ALSA) - Although you are going to wire the electronic pump with an aftermarket sensor ?
  3. Throttle position sensor (needed for the trans as well)
  4. An ECU for the 722.6xx trans - there is a guy in Denmark who has programmed one (ofgear.dk) - Note that Buldurs controller will interface with it and share TPS etc
  5. Electronic to mechanical converter for your speedo
  6. Custom rear cross mount for the back of the trans
  7. Tailshaft mod for FlexPlate and length
  8. GP Relay etc
You could fit a 722.3xx from an OM602/3 etc if you want to avoid all the trans teething issues tho a 722.6xx has overdrive and torque lockup so is much more economical

Good luck and keep us posted as I still may do it one day (and I have an OM605 plus the arms and IP)
And what about that pesky 3.69 rear end in the W123? Will the RPMs be too high at 70-80mph with the auto box?

The W202 sits at 25-2700 at those speeds (wrong tire height at the moment, so lower with proper size) and I believe it's a 2.88 final drive ratio (correct term?).
 

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240d with om605 swap in progress
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Discussion Starter · #20 ·
Just remember that the W202 transmission doesn't have a speedo drive, neither mechanical nor electric. W124 or W201 transmission is preferable.
Does that mean neither the manual nor automatic w202 transmissions have the speedo drive?
 
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