87 300D Engine and Tranny into an 84 300SD - PeachParts Mercedes-Benz Forum

Graplr · #1 08-18-2008, 06:32 PM

At this point it is purely speculation if the 87 engine and tranny are any good.

But one of the local junk-yards just got a 1987 300D in. My 84 300SD has been sitting for about a month now with a bad engine and a bad tranny. So I have been keeping my eye open for something to pop up. Since they only inventory vehicles, not condition/parts I will have to go check it out myself and figured I'd ask the pro's on here if it is even worth going to check out.

I realize the engines are completely different and I'm sure many of the electrical/vacuum stuff would be a major consideration.

How hard of a swap would this be?
Thanks,
-Ryan

(I've also been talking to a guy with a very rusty 116 81 300SD)

Astroman · #2 08-18-2008, 11:20 PM

I'm planning on doing the same swap. Since I'll be putting a new engine in my 300sd, I figured it might as well be a 603. Should be pretty straight forward. Let me know how it goes.

sixto · #3 08-19-2008, 01:56 AM

You'll need the engine mount arms and engine mounts from an 86-87 300SDL or 90-91 350SD/SDL.

You can probably get creative hooking up the 603 to the SD radiator and oil cooler if you can't find proper SDL parts. Same with the air cleaner.

A 300D IP is set-up for a throttle cable. I don't know if it has the same bellcranks as an SDL IP to make it easy to adapt a 126 throttle linkage.

A US 603 needs the EDS module (ECU) to control idle. If push comes to shove you can set base idle higher and go without EDS.

A 300D transmission has a mechanical speedo cable, a 126 has an inductive speedo. I don't know how to make them communicate. Maybe you can fit a 124 speedo in the 126 gauge cluster. That's gotta be easier than swapping the tranny tail housing.

I don't know if the SD cruise amp and connectors will work with a 603 actuator.

I don't know if an SD AC compressor will attach to a 603.

Sixto
87 300D

777funk · #4 08-19-2008, 08:21 AM

You could just buy an SDL. I saw a very nice body SDL sell for $800 last week. It had 270k on it. But still!

I'd bet if you look hard you could find a complete SDL for probably what the junker will ask for the engine/trans.

That'd be too easy

but why would anyone want to go through the trouble if prices were similar.

You'll have to watch for a deal on one... but then again putting a completely different engine in will take some time and work too!

The 603 is a great engine. It's got it's common problems. Wiki-Pedia calls it a trouble engine and that getting one that will last is a crap-shoot. But if you read here much, you'll see most people aren't complaining about cracked heads... I think??? I haven't had to deal with it yet. But I bought a 617 powered 300d just incase

Hatterasguy · #5 08-19-2008, 02:11 PM

Thats a great idea! Put a good diesel in it, use that old tractor engine as a boat anchor!

LUVMBDiesels · #6 08-19-2008, 02:39 PM

The engine mounts are the same from the SD to the SDL. you will need the proper arms that bolt to the engine though.

The Ac compressor from the 300D should be a nippondenso and will work. The SD compressor is not set up for the serpentine belt and would be a problem.

I bet the oil cooler and air filter from the 300D would work in the SD-603 as well.

For the speedo, I think swapping tailshafts is the way to go. That way you should also be able to keep the SD drive shaft unless the 300D transmission mounts in a wierd position like too far forward...

Sounds like a fun project...

Lukejt · #7 08-19-2008, 09:04 PM

Quote:

Originally Posted by 777funk

The 603 is a great engine. It's got it's common problems. Wiki-Pedia calls it a trouble engine and that getting one that will last is a crap-shoot.

ANYBODY can post in Wiki....

I've got a 603 with the original head coming up 205kmiles, no problems. The one thing I don't worry about is this motor letting me down any time soon. I've owned the car for 4+ years now. It's a daily driver and even pulls towing duty for dirt bikes. Once I even pulled a way too big/heavy trailer several hundred miles with it. I make sure to keep an eye on the temp gauge. The car impresses everybody who rides in it. It goes 0-60 in 10 seconds, but once it's on the highway at 80 or so it's even more impressive, it really moves out and will just stay at speed with little effort. The motor sounds so sweet just singing along at around 80mph. I'd rather have another used MB with the 603, rather than a less powerful 5 banger.

I love my car, even though lately I've had some nagging issues (the motor is not one of them), the door locks have quit (electrical, not vacuum), and there's intermittent short circuit in the left side running lights. It's had the trap removed by the dealer decades ago, so no worries there. It does have some oil/tranny fluid and diesel leaks, but I'm going to start fixing things little by little.

The '87 300D is a classic, great handling cool car and the M603 is a really impressive piece of engineering, in this owners opinion.

That's quite and ambitious project!

PS, I'm an old user, must have lost my username due to an email address change.

Lukejt

Graplr · #8 08-19-2008, 10:27 PM

Well I made the guy with the 81 116 an offer of $600 and he took it, so it looks like I won't be venturing down this path. The engine and tranny are strong and that is the most important thing. Then I will part the rest out and hopefully make my money back. The driver side undercarriage is rusted through.

Thanks for all your input. I will be posting another thread about the new project when I get it up and running.

-Ryan

Hatterasguy · #9 08-20-2008, 02:19 PM

Quote:

Originally Posted by Lukejt

ANYBODY can post in Wiki....

I've got a 603 with the original head coming up 205kmiles, no problems. The one thing I don't worry about is this motor letting me down any time soon. I've owned the car for 4+ years now. It's a daily driver and even pulls towing duty for dirt bikes. Once I even pulled a way too big/heavy trailer several hundred miles with it. I make sure to keep an eye on the temp gauge. The car impresses everybody who rides in it. It goes 0-60 in 10 seconds, but once it's on the highway at 80 or so it's even more impressive, it really moves out and will just stay at speed with little effort. The motor sounds so sweet just singing along at around 80mph. I'd rather have another used MB with the 603, rather than a less powerful 5 banger.

I love my car, even though lately I've had some nagging issues (the motor is not one of them), the door locks have quit (electrical, not vacuum), and there's intermittent short circuit in the left side running lights. It's had the trap removed by the dealer decades ago, so no worries there. It does have some oil/tranny fluid and diesel leaks, but I'm going to start fixing things little by little.

The '87 300D is a classic, great handling cool car and the M603 is a really impressive piece of engineering, in this owners opinion.

That's quite and ambitious project!

PS, I'm an old user, must have lost my username due to an email address change.

Lukejt

Oh yeah, the engine has been the cheapest and least troublesome part of my car.

LUVMBDiesels · #10 08-20-2008, 08:04 PM

Quote:

Originally Posted by Hatterasguy

Oh yeah, the engine has been the cheapest and least troublesome part of my car.

Mine just hit 300K with no issues. I have allthe records going back to 1986 and the head was never off the block. Just timing chain, water and vacuum pump replacements... runs at 85 degrees all day and gives me 28~30mpg! I will never go back to the 61x series.

a2t · #11 08-20-2008, 09:16 PM

ditto for me, 276k last 30k on wvo. no chains yet but im thinkin about it...this would of been a cool project, goes to show the 87 sdl is creme of the vintage benz line up.

Quote:

Originally Posted by LUVMBDiesels

Mine just hit 300K with no issues. I have allthe records going back to 1986 and the head was never off the block. Just timing chain, water and vacuum pump replacements... runs at 85 degrees all day and gives me 28~30mpg! I will never go back to the 61x series.

Hatterasguy · #12 08-20-2008, 11:23 PM

Original head and head gasket on mine. It will take me another decade to hit 300k though.

For a "bad head" its doing pretty well.