She ('79 240D) has been shaking quite a bit lately: I am replacing all engine mounts
 

With engine at idle speed when cold, my beloved 240D has been shaking a lot.
On close inspection, I have become aware that the passenger side motor mount is completely shattered - it's metal to metal - and the front mount is also pretty much gone. So I have ordered all four mounts, just to be on the safe side once I get to work under the car.
Luckily enough the '79 240D with manual transmission does not feature the engine shock absorber, one less thing to worry about... :)

Yesterday the UPS guy knocked on my door and there was a little package. Here's what was inside:

Attachment 97409

On the top: the two SIDE MOTOR MOUNTS, aka front engine mounts in the FSM. They are identical.

Bottom left: the REAR ENGINE MOUNT, aka trasmission mount.

Bottom right: the FRONT MOUNT, aka engine stop in the FSM, aka front engine stop, aka t-strap mount, aka anti-torque mount. Different people give it different names ... after some initial panic and a bit of confusion, I was able to assign the various names they go by to each correctly so that I could confidently place my order.

Once I get the old ones out of the car, I'll post pictures so you can see the condition they are in.

First step is degreasing/pressure washing the engine and underneath the car, so as to be able to tell what's what and not get too dirty - will do that this Monday.
Then on Tuesday, hopefully, I will get down to business and replace them all.

I have the FSM and am following the procedures in 00-211, 00-212 and 00-215 to replace the mounts, and yes, I have already used the search function here as well, so I think I've got the whole thing pretty much down.
However, if anyone who has been there, done that, wants to contribute a few suggestions thought to be valuable, I'll definitely be more than glad to listen to your advice... this is my first time tackling this job and it seems sort of a big one, so it would be great to get all the help I can get. :)

Got pics of the car?

Here you go :D

(As far as pictures of the old mounts as currently installed, I'll take them tomorrow after degreasing/washing the engine)

http://www.peachparts.com/shopforum/...ure3581-lm.jpg

I need to do this too, looking forward to seeing how it went.

Both the engine and the front area underneath the car were degreased/washed early this morning at a car wash. Now everything is much cleaner and more visible. Unfortunately, I wasn't able to take pictures of the old side mounts while they are still attached to the car....they are far too below and out of sight for my camera.
In the picture below, however, you can see how that rubber line is being squeezed between the air filter housing (which came down along with the engine because of the shattered passenger side motor mount) and the upper shock absorber mount, and cut by that large washer.

Attachment 97448

Obviously, the air filter housing is also being stressed because of the engine pulling it down against that structure. I imagine other components are also being affected by the engine coming that much down on the passenger side.

Tomorrow I'll get down to it with my first attempt at changing all four mounts. Wish me good luck, we'll see how it goes.

By the way, the passenger side front shock absorber blew up a while ago, probably related to this situation. You can see how much damage a failed motor mount can do if left unattended. I'll be replacing both front shock absorbers next, after taking care of the engine mounts.

Shocks can get expensive!!!

I have the exact same car (79 240D) and did the two motor mounts a couple months ago. Still have the T-mount sitting in my garage waiting to get put in.

Remove bolts, jack engine up with a piece of 2x4 under oil pan, slide old mounts out. Engine should be jacked up enough you should be able to slide the driver side mount in (less access). Then I found the trick to getting the passenger side in is to grab the top of the valve cover literally push the the top of the engine toward the drivers side to gain clearance to slide the passenger side in... (I was using a large pry bar with one hand and trying to slide the mount with one hand to no avail...)

Remember removing the air cleaner assembly is a must with the passenger side. Please let us know how it goes, especially the t-mount as I don't even know how to install, just noticed the mount was shot when I was replacing the oil pan gasket...

Uneasy, sure, I'll report back and give you the details.....
I might not be able to do it tomorrow as planned because something has come up and it will be a very busy day for me, but I'll definitely do it by Wednesday at the latest....it is stupid to keep driving the car this way, and this is my daily driver....
I believe it would be a very good thing to replace your shot T-mount ASAP.... Along with the transmission mount, it prevent the engine from rocking back and forth... If allowed to do that, it will destroy the side mounts you recently installed. Usually, the transmission mounts in our cars last forever, but not so with the front mount (engine stop). In most cases, when one of the two side mounts (or both) is shot, the front mount is also gone. I got a new transmission mount just in case.
Thanks for the tips....I'll definitely use them. :)

On a side note, I'll need to replace the oil pan gasket too, my only current leak is from there.....how difficult was that on your 240D?

Be sure to use a GOOD QUALITY hex wrench to remove the MM bolts. A cheap wrench can/will slip possible rounding out the hex and adding to your difficulties. PB Blaster, or similar, in liberal qualities may help.

I have a high quality 8 mm hex socket and also good 6 mm and 8 mm hex keys. I'm getting a 6 mm hex socket today and while there I'll look into the PB Blaster, thank you for your suggestion. :)

HELP!!!
 

I finally got under the car this morning and was able to remove the two engine bearer bolts from below (one per mount) thereby technically freeing the engine from the frame.

However, when I attempted jacking the engine up with a piece of 2x4 under the oil pan, the whole chassis began lifting up along with the engine.
I do not understand how that is possible...I need someone to help me figure out why the whole chassis lifts up along with the engine. With the two engine bearer bolts removed, the engine should be lifting up from the frame, freeing the side mounts so that they can be replaced with the new ones....but the whole car comes up when jacking up the engine via the oil pan.

Why is that?

By the way, when I first looked (not to closely) at the front mount, I reported that it was pretty much gone. However, taking a close look today, there is no front mount and front mount assembly to speak of under my car. The whole thing is gone - and there is no lower or upper strap, the whole front mount assembly is just not there... many thanks to the PO or whoever left this situation unattended to before him.
It's amazing to me that I could drive this car this way for the seven years of my owning it. Unfortunately, I did not even know that something was missing and should be there before learning about engine mounts these past few days, so I did not do anything until now to take care of it.

I'd appreciate it if someone here can help me figure out why the engine is not lifting from the chassis after removing the two engine bearer bolts. I looked very closely and nothing seems to prevent the engine from going up. Could it be that the rear engine mount (transmission mount) needs to be released as well? Nobody who has replaced the side mounts has ever mentioned in this forum having to do that, as far as I remember what I've read so far.

I'd appreciate some help with this...thanks.

Assuming that you've got all four tires on the floor while you are doing this, a little rise of the whole front end as you take the load off of the springs by lifting the engine can be expected . If your mounts were really crushed, then you may have to raise the whole thing quite a ways to get the clearance that you need. The engine should rise eventually if your engine stop is disconnected. I hope you've taken the necessary steps of loosening the radiator shroud, disconnecting accelerator linkage, and having rear wheels chocked (both ways).

That's the funny thing....the engine just won't go up!
Yes all four tires are on the floor (front ones on low ramps with chokes, rear ones are blocked by the manual transmission being engaged in first gear).
I've raised the engine as much as 2-3 inches, but the whole car travels up with it, there is absolutely no added clearance to unscrew and take off the old mounts.
As I said there is no engine stop installed, not even the engine stop assembly is installed on the car.
The only thing I can think of, could it be the car has engine shocks installed and they are preventing the engine from being lifted?
Since the FSM states in several places that the 616 engine in type 123.123 chassis AND MANUAL TRANSMISSION absolutely comes with no engine shocks, I did not look for them... But will do that tomorrow morning, just in case the thing was messed up by some well-meaning ignorant fellow who took out the engine stop and somehow added the engine shocks. The FSM clearly states that the engine shocks should not be installed on this car with manual transmission.

Any other idea?

Yes thanks by the way, fan shroud and accelerator linkage were disconnected before attempting to raise the engine.
If it is as you say, how far up is the whole car supposed to travel (because of the springs) before the engine starts disengaging from the mounts? As the front end was raised about 3" by jacking it up at the oil pan, I was concerned that continuing to raise it that way, seeing the engine was not detaching from the mounts, it might break something.
You are probably right, as it makes sense.

I've done this job a couple of times on W123's, and many times on various other vehicles. I don't think that I'd want to try it with the vehicle out of level. I don't see any reason to have the front up, other than to ease removal of the engine stop. In any case, I would never get under a car on ramps without having the other pair of wheels chocked.

I'd expect up to three inches of lift before the engine starts to move. I'd stop when I see the tires leave the floor. Perhaps your front springs are sagging badly. Not to suggest that you've made an error, but are you sure that you got the bearer bolts out? If you rock the engine, then you should see it moving free from the mounts, or at least see the shields wiggling around some.

Well I had to put the front tires up on (low-level) ramps because otherwise there wasn't enough space for me to get under the car to remove the two engine bearer bolts. But no need to put it on ramps now that the engine bearer bolts have been removed. I'll try again tomorrow morning with the car level on ground and will attempt lifting the engine up higher, as you suggested.

But to lift the engine up via the oil pan...wouldn't it too much stress on the oil pan (collapsing it) if I were to lift the car up until the tires left the floor?

Yes believe me, I got the two engine bearer bolts out...they are two M10 bolts which I removed with an 8mm hex socket that go right into the side mounts from below.

And no, I've tried to rock the engine by pushing hard on the valve cover, but it is stuck, it does not move at all. Should I be concerned at this point, or just go ahead and raise the engine more tomorrow as you said?

I questioned whether you'd actually gotten the lower bolts out because I didn't find it necessary to raise the car to access those bolts, but working from memory I can't picture any other 10mm bolts in recesses that you could have removed down there.

I'm half joking here. I would not attempt to raise the tires off the floor by jacking under the oil pan. I'd bet that the pan can take the stress, but it wouldn't be very gentlemanly for me to make that bet with your car. I would go up almost that far--to the point where some of the weight is off the wheels. At that point you should at least get the engine to rock fairly easily. You mentioned the possibility of there being engine shocks installed. You're correct in assuming that there shouldn't be-- but since your front engine stop is missing, things may have been done to this car that shouldn't have been done. If an engine shock was installed, it should be attached to the drivers side engine bearer. You can tell at a glance.

Other than that remote possibility of an improperly installed engine shock, there is nothing other than gravity holding down the engine if the lower bolts are out. The engine will lift. If not, I have no explanation.

I would. I'd also locate the missing parts for mounting the front stop and install it, as well as replace the rear stop. Since you've already bought it, you might as well put it in.

Thanks Left Coast :) I will look to see whether there is an engine shock installed on either side and then try again to lift the engine, this time pushing it a bit higher, and see what happens.

when I did my mounts I had that "why is the whole car going up, and not just the engine" moment, but just kept jacking, I think if you jack a little more the engine will separate from the rest of the car.

make sure the piece of 2x4 under the oil pan is large enough to disperse the weight along the whole width of the pan

You were right, it worked just fine by raising more the engine.
By the way, there were no engine shocks installed on my car.

Here you can see a couple of pictures of the old side mounts
(sorry, I realized the pictures were so dark only after the
old mounts were thrown away):

Attachment 97488

Attachment 97489

The one on the left (in both pictures) is the passenger side mount.
You can see how it completely collapsed.
Because of it, the engine was about one and a half inches lower
on the passenger side than on the driver side, and it had also
drifted about one and a half inches in that direction, thus
pinching that line as shown in the first picture in this thread.
Possibly as a result of it, when lifting the engine by raising the oil pan,
the engine bearer on the driver side came up much more than
the one on the passenger side. That way it was going to hit the
return hose to power steering system right were it attaches
to the connection at the power steering box. So I had to disconnect
that return hose, drawing first the ATF out of the power steering
pump reservoir, as per FSM 00-211 instructions (now I have to
refill the power steering system with PS fluid as a good amount of
the old ATF ended up on my garage floor... :( and will have
to bleed the system too..). Also as the engine went up, the fuel
line to fuel filter got fully extended and ultimately disconnected,
also spilling some fuel on the floor :( I later had to use the fuel
hand pump to bleed the fuel system.

I found that the passenger side mount was missing one of the two
screws, so I now do need one. I also need the front mount (AKA
engine stop, AKA t-mount) assembly, which is not currently
installed on my car....meaning the upper and lower straps and the
four M8 bolts (my car still has the adjusting screw installed).
So, if anyone has an extra side mount screw, or the front mount
assembly, and is willing to sell them to me, that would be great.
:)

To sum up the procedure I went through for replacing the side
mounts, hoping it will be useful to someone reading this, these
are the steps I took (which, unfortunately, not even the FSM lists
fully). Keep in mind that I did not have to loosen and adjust the
engine stop, which is part of the procedure if you have it on your
car, because I don't have one currently installed. Also my car did
not come with engine shock absorbers. If you have a 240D with the
automatic transmission, you probably have one and must unscrew
the engine shock's lower nut while securing the piston rod so that
it doesn't turn, BEFORE lifting the engine.

Tools I Used for the Job:

- 10 mm socket (to remove air filter assembly)
- Small screwdriver, to remove dirt from the hex heads before
attempting to unscrew them
- A good 8 mm hex socket (engine bearer bolts at side engine mounts,
which are removed from below the car)
- Adjustable wrench (to disconnect/reconnect return hose to
power steering system)
- Medium size blade screwdriver to disconnect/reconnect the fuel line.
- A good 6 mm hex socket (screws on side mounts, removed from
above)
- 13 mm wrench to release adjusting screw on rear (transmission)
mount in order to more easily align engine bearer tips on mounts.
- 3/8" ratchet with short and medium extenders
- 22 mm wrench to release bolt over fuel filter in order to bleed the fuel
system (since my fuel line to fuel filter was disconnected)


Step by Step Procedure I used for Removing Side Mounts on my 1979
240D, manual transmission:

a) Remove air filter assembly, in order to access passenger side
mount
b) Disconnect radiator shroud (or radiator fan will hit it when
you raise the engine)
c) Disconnect accelerator linkage (just the last link to the
chassis)
d) Use a small screwdriver to clean out hex heads. The hex bits
must go all the way in and fit properly, otherwise the heads
will strip.

1) Unscrew engine bearer bolts at engine mount, working from
below. In my case these were M10 x 40 bolts, one per mount.
2) If you have power steering, you will probably have to
disconnect return hose to power steering system. Before
doing so, draw fluid out of power steering pump reservoir.
At least watch out for that hose while lifting the engine,
you don't want the engine bearer to hit it.
3) Raise the engine, applying jack to oil pan. Make sure to
insert a large block of wood between jack and oil pan to
avoid damage to oil pan. At first both the chassis and the
engine will rise together because the springs will push
up the frame as you are lifting the engine. In my case,
both the chassis and the engine rose together about 5"
before the engine started lifting from the chassis.
While doing this step, keep an eye on the power steering
pump hose (if you haven't disconnected it) and the fuel line
to fuel filter (which may get fully extended e disconnect,
depending on how much you will have to raise the engine
to get clearance on both sides). Before this step, you
should have disconnected both radiator shroud and
accelerator linkage.
4) Withdraw mount shields.
5) Remove mount screws and pull out old engine mounts.
6) Put in new side engine mounts and put back screws. In my case,
the engine rose more on the driver side, so I installed passenger
side mount first by pushing on the valve cover toward driver side
so as to raise a bit more passenger side's end of the engine and
slide passenger mount in.
7) Reinsert mount shields.
8) Fully release adjusting screw on rear engine (transmission) mount in
order to more easily align the threads in the engine bearer tips with
the holes in the chassis so that you can later reinsert and tighten the
engine bearer bolts.
9) Lower the engine very slowly, making sure the engine bearer tips go
right into the center of the mounts. You may have to use a pry bar (I
used one with a flat, bent tip) leveraging between the mount's top
and the engine bearer tip while rocking the engine (hand on valve
cover) back and forth in order to properly align those engine bearer
tips. It may take several attempts and a lot of time...this is especially
true if one or both of the old mounts were damaged/collapsed and
consequently the engine has been sitting in an inclined position for
a while. If needed, you can also use a smaller pry bar or large
screwdriver from below, through the chassis holes, to push laterally on
the engine bearer bolts' heads once the latter have been inserted
and screwed in most of the way, if you still need to move the engine
slightly for better alignment on both sides. I had to do this too.
10) Once you are satisfied that the engine bearer tips are
positioned in the center of the mounts and that holes and threads
are properly aligned, reinsert M10x40 hex head bolts from under the
car and torque to 40 Nm.
11) Remember to tighten up adjusting screw on rear (transmission)
mount.
12) Put back whatever you disconnected/removed in the previous
steps.
13) If fuel line and return hose to power steering system were
disconnected, you will need to bleed fuel system and replenish PS
fluid and then bleed PS system.

And, finally, enjoy it! Which is the most important part of what we do
while taking care of our old, wonderful, beloved cars!
:)

Happy Thanksgiving to You All!

when you put that t-mount in, don't forget to add more of those very detailed instructions. Thanks in advance...

Will do :)

I am waiting till I can find/buy the missing t-mount assembly somewhere.

I'll soon also replace the rear engine (transmission) mount and add the installation steps to this thread.

Does anyone have an extra side mount (top) screw or a t-mount assembly to sell me? (I'm in Los Angeles.)

I drove the car this morning and I have to say I am very pleased. :D

No more vibrations all over the place and, as an added benefit, the new mounts seem to have slowed down the idle speed, which was too fast, by repositioning the engine. The engine sounds wonderful now, as it should...and you cannot see the engine vibrate at all... :)

Attachment 97505

Attachment 97504

Compare the previous picture (top) with the new one: it will give you an idea of how much the collapsed passenger side mount had caused the engine to move down and to the side. There were a few strange noises coming from under the hood before with the engine running...but they are all gone now... :)

Just replaced my t-mount yesterday. It is pretty straight forward...

1. Raise vehicle or use ramps as I did
2. For the two small nuts use a 13mm wrench to hold the bolt while using a 13mm socket/ratchet to take off the nut.
3. For the big bottom bolt, There is a "keeper" holding the head of the bolt so it does not back out, Just lift and pivot out of the way.
4. Use a 19mm wrench to back out the large bolt from the plate it is threaded into. (Mine required a few strikes from a deadblow hammer on the wrench to get the bolt to back out)
5. When the large bolt has backed off the plate enough, remove plate, clean everything up, replace mount, and nuts and your done! very easy!

I just did mine and cut two 10" X 13" pieces of 3/4" plywood to fit the oil pan. Lifted the car using a hydraulic jack and placed the front tires on steel ramps. Then removed the radiator shroud clips, air cleaner and upper radiator hose along with the throttle linkage at the firewall. Loosened the 8mm motor mount bolts using a 1/2" drive socket then lifted the engine by placing the two 10"X13" pieces of 3/4" plywood under the oil pan. The 10" X 13" size worked well to disperse the pressure exerted by the floor jack. Once lifted, I placed a 6" 2X4 piece of wood under the bell housing of the transmission supported by a jack stand (just in case the hydraulic floor jack failed). Then removed the air cleaner to allow easier access to the passenger side mount. After this, motor mount removal/install was easy.

To adjust the t-mount properly, you will have to first release adjusting screws at both t-mount (aka engine stop) and rear engine mount. Then slightly rock engine from side to side with your hands, and later use the special tool (you can build it or something similar yourself easily by following directions in the FSM - see suggested links below) to properly position the t-mount. Finally, having done the above, you can tighten adjusting screws at both t-mount and rear engine mount. Lastly, withdraw the special tool from t-mount. At this point you will have a functional, properly adjusted t-mount.

It's easily done if you look at the drawings when reading the instructions. You can download the two FSM (with drawings) relative to this job here:

00-215 Removal and installation of front engine stop:
http://www.google.com/url?sa=t&rct=j&q=00-215+%22engine+stop%22&source=web&cd=1&ved=0CC4QFjAA&url=http%3A%2F%2Fwww.tglmarketinginc.com%2Fmbfor um%2Fservman%2FMB%2520Service%2520Manuals%2Fwww.pauldrayton.com%2Fuploadfiles%2Fmerc%2FService%2FW12 3%2Fw123CD2%2FProgram%2FEngine%2F615%2F00-215.pdf&ei=Na3WTqbMMe7JiQL28LTlCQ&usg=AFQjCNFlyfQRK5zUcMm-B7iLDvdabR4WuA

00-220 Adjustment of engine stop:
http://www.google.com/url?sa=t&rct=j&q=00-220+%22engine+stop%22&source=web&cd=1&ved=0CC4QFjAA&url=http%3A%2F%2Fwww.tglmarketinginc.com%2Fmbfor um%2Fservman%2FMB%2520Service%2520Manuals%2Fwww.pauldrayton.com%2Fuploadfiles%2Fmerc%2FService%2FW12 3%2Fw123CD2%2FProgram%2FEngine%2F615%2F00-220.pdf&ei=NazWTtjfOejViALWhfDGCQ&usg=AFQjCNErDxhOo74UcYsJ2mcTpGlHXkLeOw

I hope it helps.

The car will naturally come up some, not because you're lifting the whole car, but because you're taking the weight of the engine off the springs. :)

Transmission mount (rear engine mount) removal and installation
 

I finally got to replace my transmission mount today.

Tools needed for this job: 19mm wrench, 13mm wrench, 17mm socket, 13mm socket, 6mm hex key, 3/8" ratchet with short extension.

First of all, there was an old, alien transmission mount installed, nothing like it should have been on this 123.123 240D. You can see it on the left, in the (bad) picture below, compared to the brand new mount which went in, on the right.

Attachment 98583

The old mount has a strange enough 1" x 3/4" square tubing in the place of the round pipe that is proper for my car. This old mount doesn't look like any of the four mounts illustrated in FSM 00-212 (Removal and installation of rear engine mount) meant for type 115.1 and type 123.1 MB's. I have no idea why it was there, it shouldn't have been. It very likely contributed to the old vibrations.

Also, perhaps the engine bearer currently installed on my car is not the proper type, as the new mount (No. 123 240 20 18, which is the proper one for my car - meant for chassis above 050513 with manual transmission) had a round pipe which was way too long to fit into the engine bearer.
Therefore, I cut an 8mm length off it:

Attachment 98584

and after that it fit into the engine bearer just fine.

The removal/installation procedure is very straightforward (I did not have a front engine stop to preliminarily release the adjusting screw of, which would normally be the first step of this procedure, since I don't have one on my car yet, still waiting to find an assembly for it somewhere...my car came without one when I bought it 7 years ago):

1) Unscrew 19mm nut attaching the top of the old mount to the frame.
2) Release adjusting screw (using a 13mm wrench in conjunction with a 6mm hex key)
3) Unscrew the two bolts from below (13mm socket) that attach old mount to engine bearer.
4) Since I have a manual transmission, at this point I simply supported the transmission by use of a jack.
5) Unscrew the two large bolts (17mm socket) and pull out engine bearer.
6) Remove old mount from engine bearer and place new mount in, making sure you insert adjusting screw WITHOUT TIGHTENING IT, and use the two bolts to attach mount to engine bearer WITHOUT TIGHTENING THEM. Make sure you place the mount in the engine bearer facing the right direction: compare it to the upper frame where it will be bolted to and you will promptly understand that there is a right way to put it in.
7) Screw back engine bearer to frame using the two large bolts WITHOUT TIGHTENING THEM.
8) Lower and take out of the way jack that was supporting transmission.
9) Tighten engine bearer. Do not use a breaker bar, even though these are big bolts. Proper torque here is only 30 Nm!
10) Tighten bolts attaching mount to engine bearer (also at 30 Nm).
11) Tighten adjusting screw (40 Nm).
12) Finally, screw 19mm nut on (70 Nm).

Done! :)

With the two new side mounts, this new transmission mount and the four new bilstein shocks I installed recently, the car now rides like a new Mercedes! :D Even though it is still missing a front engine mount (engine stop).

The springs may take more to unload than your current 2-3 inch lift is. You are lifting most of the engine weight off them remember. That engine if fairly heavy for a four banger as well. Take a look at your new mounts for the fastenings. If you have removed what obviously is indicated on them lift the engine higher.

I have seen the exhaust header pipe bolts loosened to do this as well. Do not know if it is a neccesity on this model. It would not totally prevent some mount separation from the chassis anyway.

The length of the transmission mount's round pipe which was cut out...that's horizontally, not vertically, if that's what you thought. The pipe was too long to fit (horizontally) inside the engine bearer....so I shortened it, but that does not affected height at all; as a matter of fact the new (appropriate) transmission mount has the transmission stand slightly higher than the old (incorrect mount) which was previously in my car. That's something I noticed right away, even though the old mount which I took out was in perfect condition.

With the new bilsteins, my 240D stands actually 15mm higher than with the old ones on all four wheels, measured at the highest point at the outside of the wheel wells, so that translates now in the springs unloading more than they did earlier.
All of the three mounts which I have newly installed lift the engine higher than the old mounts for sure...as the front right mount was badly damaged and compressed and the new (correct) transmission mount adds more height than did the old incorrect one. Therefore, it should be all good.

Is this what you were pointing at, or have I misunderstood what you meant to convey? If so, I'd appreciate your explaining your point better.