How I took out my 1981 W123 300D (euro) non-turbo engine - PeachParts Mercedes-Benz Forum

Stretch · #1 12-08-2010, 03:59 AM

I read somewhere on this forum that there isn't an W123 engine removal how to. Having just done the job quite recently here's a write up for you all. I admit that this is a pretty tedious thread – but I've added in many photographs that may be of use even if you are not taking out your engine.

I want to make this clear at the beginning: I've only done this job on a 1981 W123 Euro 300D => OM617 non turbo motor.

It is a bit of a marathon but it is quite simple really...

...so here is the short version:-

All you need to do is disconnect everything that is attached to the engine and lift it out.

That's it.

That's all you do.

If you want the long version – the very much longer version read on!

Stretch · #2 12-08-2010, 03:59 AM

1) Think about whether you are going to remove the bonnet / hood or not. I guess you could put the bonnet in its vertical position and get the engine out. However, as I'm working outside, one gust of wind could have really ruined my day so I opted to remove it. If you are doing this you need to make a nice safe place for your bonnet / hood before you start!
2) Get a decent engine crane. I bought a 2 ton model and used the 1 ton extension position with a load distributor. If you are going to hire or buy a 1 ton model – make sure that the point at which you connect the hook (the bit that will hold the engine's weight) is going to go far enough over the engine in your car. If you don't have this hook point more or less in the centre of gravity of the thing you are lifting the whole weight of the engine will swing to compensate! This is when you could do yourself or the car or the engine some damage.
If you don't go for something that is purpose made – make sure that the structure and the lifting gear you are using is capable of lifting the engine (and gearbox) together.
DO NOT OVERLOAD YOUR LIFTING EQUIPMENT – even if it will “only be for a few seconds”
3) Remember that when you lift the engine out of the car the front suspension will raise the front of the car. The cross member at the front of the car – the bit that holds the hood / bonnet catch – is likely to go up in the air by at least 6 inches. It is best to make sure you can lift the engine over this before you start. However, as you'll probably just end up guessing if it is going to be OK or not it is worthwhile remembering that if you don't have enough height in your lifting gear you can do the following things:-
● Let air out of the tyres
● Put the car on low axle stands and remove the front wheels
● Get different lifting gear!
It is best to consider these options before you have the engine dangling on your lift.
4) Consider whether you're going to need an engine stand or not.
5) If you're working outside consider getting a cheapo party tent that will protect you from the bright sun (if you're so lucky) or more likely the rain.
6) Although it might look a bit daft consider labelling each wire / hose / pipe that you are going to disconnect. This is advisable if you are not used to working on your car / this type of car. It is also pretty handy to take pictures of things as you go – then you'll know how to put them back. Experience has taught me that you nearly always end up putting stuff back together in a rush and the daftest most obvious label often helps when you're in a panic / tired / pissed off

Please note although I'm not going to cover the following way of doing things you could in principle remove the gear box first – dropping it from the engine under the car – and then lift the engine out. This isn't the easiest way of doing things but it could be done if for some reason you couldn't lift the engine and gearbox out together: Like when you haven't got lifting gear that is strong enough. I wouldn't recommend it as I think the chances of damaging the gearbox are greater – but I guess it could be done that way...

During my engine rebuild I've been busy weighing my engine and other related parts so I can post the weights you can expect to meet. I couldn't find this data and I still haven't found this data anywhere else – I've only come across guestimates.

Start the job by disconnecting the battery.

Stretch · #3 12-08-2010, 04:00 AM

A selection of sockets 6mm to 24mm
A selection of Allen keys – preferably Allen head sockets (check for any torx heads – these are not fitted as standard but they do find their way onto these cars!)
15mm open ended spanner for undoing propshaft flex discs
15mm socket for undoing propshaft flex discs
7mm open ended spanner for holding flat on engine shocks
41mm and 46mm open ended spanners for “collapsing” propshaft
An engine crane
A load balancer (recommended)
Cross point and flat blade screw drivers
Water pump pliers for removing engine shocks
Drip trays for emptying fluids
Rags for wiping stuff clean and protecting stuff
A digital camera (recommended – take photographs as you go!)
Masking tape (recommended – for labelling the parts you remove)

Stretch · #4 12-08-2010, 04:03 AM

Open the hood / bonnet and disconnect the windscreen washer hose at the point where it splits between the two sprayers on the upper surface of the hood / bonnet (see photo). Pull the hose out of the way.

Arrange some protection on the windscreen so that when you undo the bonnet bolts (that attach to the hinges) the chances of scratching or damaging the scuttle or the windscreen is slim. I used some garden furniture cushions and some rags.

Wedge a broom to hold up the bonnet / hood (see photo).

If you can, release the spring tension of the hinge mechanism by flipping the vertical position catches as though you are putting the hood / bonnet into vertical mode! Mine were really stiff so I couldn't do that...

...Anyway undo the bolts that attach to the hinges (photo) and lift the bonnet / hood away from the car. Don't worry about dropping the broom! I managed to do this fairly easily by myself. Being over 6 foot tall with long arms helps. It is probably easier if you can find someone to help you with this though. I admit that this is quite an awkward piece of steel to lift with outstretched arms.

Stretch · #5 12-08-2010, 04:06 AM

You're going to need to drain the coolant out of the cooling system at the very least. There is a screw underneath the left hand side of the radiator (see photo) and a screw on the right hand side of the engine block to drain the rest of the system (see photo).

If you've got an automatic gearbox then you'll also have to disconnect the oil cooler lines – under the radiator. If you can find a way of stopping these lines from leaking then I guess there is no real need to drain the whole gearbox. I did do this though as it was time for another fluid change anyway... I used tie wraps and plastic bags to stop dirt from getting into the pipes (see photo).

For the engine oil cooler lines that run from the filter housing to an oil cooler next to the radiator you could also just disconnect these lines and try and stop the engine oil from pouring out. Again I drained the whole system and lifted the filter out of the housing – then wrapped the ends of the pipes in plastic bags.

The power steering pump also needs to be disconnected from the engine. I guess you could just unbolt the pump and try to tuck it away next to the windscreen washer bottle if you don't want to disturb this system... but again I drained the system and disconnected the hoses at the steering box. To drain the power steering system either jack up the car so you can turn the wheel almost all the way to the left – or if you are strong and you don't really care just turn the wheel to the left – or roll the car onto a slip plate and turn the wheel to the left (this is what I did – see photo). Next undo a 12mm nut on the underside of the steering box (see photo). The fluid will drain through the steering box nicely – so you don't need to waste time trying to siphon or suck the oil out of the steering pump with a turkey baster etc. (see photo).

Stretch · #6 12-08-2010, 04:10 AM

Here are the other photos

Stretch · #7 12-08-2010, 04:41 AM

Well there you have it - I hope you haven't nodded off!

If I've missed some bits please let me know - I'll remedy whatever is needed.

I forgot to mention:-

If you are looking for engine bay pictures with out an engine in it you can find them here:

http://www.peachparts.com/shopforum/showthread.php?t=286358

And spring pocket refurbishment here:

http://www.peachparts.com/shopforum/showthread.php?t=286079

(Jobs you may want to consider doing whilst your engine is out)

I've just had a good tip from layback40 - see below in post 24:-

"You could have added, replacement is the reverse, or just whistle at the motor & tell it to get back in there!!"

vstech · #8 12-08-2010, 10:41 AM

Nice.
only complaint I have is wondering why you removed the hood?

Stretch · #9 12-08-2010, 10:59 AM

Quote:

Originally Posted by vstech

Nice.
only complaint I have is wondering why you removed the hood?

Hmmm - looks like (as usual) I've given too much information. In post #2 point 1 is about to remove hood or not to remove hood. I chose to do it because I was working outside and I imagined one strong gust of wind bending it back against my windshield. When I started the job I had no idea I'd get it all out so quickly. Over a 2 day period I probably completed the job in about 5 hours stopping for pictures etc...

I'll make an edit above to make it clearer - thanks

junqueyardjim · #10 12-08-2010, 12:23 PM

I have been involved in a number of 616/617 Turbo and you described it well and the pictures speak for themselves. Thanks. I do think the factory hooks are plenty strong enough the handle the engine remove/install operation, though it is not impossible to bend them.

junqueyardjim · #11 12-08-2010, 12:27 PM

Typically we don't remove the hood as it does lay back so nice. But remember, Army is in the Netherlands, and the wind really does blow there. I have been there and that wind is enough to take your breath away. I think what causes all that wind is all the windmills that are still turning. They make a lot of wind!

Stretch · #12 12-08-2010, 12:54 PM

Quote:

Originally Posted by junqueyardjim

Typically we don't remove the hood as it does lay back so nice. But remember, Army is in the Netherlands, and the wind really does blow there. I have been there and that wind is enough to take your breath away. I think what causes all that wind is all the windmills that are still turning. They make a lot of wind!

The buggers... though where I am there aren't that many of the old type - just those huge Californian style ones.

tomscat1 · #13 02-20-2011, 06:52 PM

I am a little late to this thread. I sought it out because I am contemplating removing the engine from my 1975 W115 300D again, and was seeking some refresher materials.

This thread is for a W123, as I understand, so it may be a little different, since I did this on my W115.
Back around 2000, I had two W115 300Ds, and I swapped the engines.... then swapped them BACK, after learning that the engine that I thought was good, was, in fact, no good. So, in the course of that adventure, the net result was that I pulled the engine three different times, and installed it twice.

The reason I am posting here is to share some info that I learned along the way. Again this was for a W115, so it may not apply completely here.

Prior to actually doing the job, I was repeatedly warned about the difficulty, and how much of a PITA it was. Except for one fella, to whom I remain eternally indebted. He said, never mind those guys.... this is the way to do it.... it is actually very easy, and a testament to the genius of the MB design:

Lift the engine with a strap, .... wrapped around the engine just behind the front oil pan sump. Leave the tranny attached. Forget the load leveler and the attachment points, you don't need them.

As you slowly lift the engine with the strap attached as above, the natural weight of the engine, with tranny, will tilt the engine at the exact angle to clear: the firewall, the front crossmember, and the front where the radiator was attached. It is unbelievable. Pure genius!

I did this procedure by myself three different times. Once I had everything detached, and I took care to use a little scissor jack under the tranny to keep it from dropping too much.... I had the engine out and on the floor in less than 10 minutes. The biggest problem I had was that, in my excitement, I knocked over my coffee mug (covered and sealed so nothing even spilled) as I rushed around the car making sure all the lift angles were clear. I knocked it over two times!!! I just couldn't believe how easy the job was! It really came out perfectly.

I have just decided that, instead of selling my beloved W115, ---which I almost did yesterday--- I am going to restore it.... it needs valves, seals and rings, I believe, and a good paint job. Also some attention to the interior, heater and A/C. It is a solid example, basically, and I have decided it deserves a freshening. It is a grand old car, and a pleasure to drive.

And, btw, I would be remiss if I failed to mention what a great write-up that was, Army. Kudos! I love to see stuff like that. Great job!

Stretch · #14 02-21-2011, 05:01 AM

Quote:

Originally Posted by tomscat1

I am a little late to this thread. I sought it out because I am contemplating removing the engine from my 1975 W115 300D again, and was seeking some refresher materials.

This thread is for a W123, as I understand, so it may be a little different, since I did this on my W115. ...

Thanks for the input tomscat1 and welcome to the forum.

When I get my engine back together again - nearly done - I'll see if I can work out if it is possible to put an engine back in a W123 without a load leveler when you are working by yourself. It is good to know these things!

John Schroader · #15 09-01-2012, 10:13 PM

Great info. Many thanks folks. Tomorrow my beloved 300D will probably sacrifice its engine so its partner (my 300SD) can live again. The 300D has a bit of rust and a couple of transmission issues and the SD engine finally gave up the ghost at some high unknown milage - odometer broke at 310K a long time ago. These articles have greatly boosted my confidence that I can, indeed, do this.