190D belt tensioner removal - who designed this $hit
 

I am planning on replacing the belt tensioner, tensioner shock, idle pulley of the 190D OM601 as it is squeaking. I thought it is a 30 minutes job but I am dead wrong. It seems there is not enough clearance to slide out the tensioner because the water pump pulley is in the way. So I think the sequence would be:

1) drain coolant, remove radiator.
2) remove electromagnetic clutch fan
3) remove water pump pulley
4) remove the tensioner

Am I correct? It is such a convoluted job. The tensioner is not doing much. It has a bearing but it is kind of oscillates to adjust the serpentine belt tension. It is a stupid over design IMHO.

Questions:

1) How do I stop the water pump pulley from spinning while I remove the 13mm bolt?
2) Is OM603 the same or similar? My 87 300D is squeaking too.

It's similar to the 603 except for the different fan clutch mechanism.

Get the $8 Harbor Freight Pully Holder tool, get more than one if you keep tools in the trunk to deal with an on the road belt failure.

Can't get the fan and clutch off with the radiator in place on the four cylinder?

are you sure? I've never touched a 601, but I've never had issue removing the tensioners on others. *if you like the 601 tensioner, try working on the 2.3 190E (not sure it's motor designation) tensioner!!!

can you take some pics of the front of the engine?

I agree
 

Here is the Performance Tool W87023 - Pulley Holding tool you need.
Pulley Spinning Tool


http://www.w124performance.com/images/M119/M119_fan_wrench.jpg
http://www.peachparts.com/shopforum/2637826-post15.html

I like this DIY because you don't need to remove the radiator, but I went further by silver soldering the cut down Allen wrench into a 71 centimeter long 2.5 mm thick wall stainless steel pipe, for leverage.
The 8 mm allen (cut down to ~30mm long) is to break free & re-tighten the center bolt.
sorry, dead link.


The FSM procedure is here - note it says the radiator must be removed, and this is true if you want to use the stubby socket (factory tool) depicted:
sorry, dead link.


Here are commercial tools for this job.

http://www.w124performance.com/images/OM603_misc/OM60x_serp_belt_tools.jpg

MB# 120589140700

Baum Tools ST3008


http://www.peachparts.com/shopforum/diesel-discussion/292188-help-pls-1998-210-frozen-pulley-belt-off-out-luck.html#post2636972

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Removed

I think I can get the water pump pulley off without removing the radiator but I will remove it anyway as it is 5sp. There is no tranny fluid connection so it is a bit easier. This is the tensioner I am talking about. It is a Royal Pain to remove. I will do it when I have the tool and parts.

When you remove the tensioner pulley, damper and spring, you can pivot the tensioner arm (picture) to a position for removal that doesn't require removing the water pump or power steering pulley. The power steering pulley is easy to remove such as when removing the vacuum pump (is yours the original style or new style?). Oddly, the water pump pulley really likes its flange.

Sixto
87 300D

I do not think you can remove the tensioner without removing the water pump pulley.

I don't know, man, it looks tight but I bet I could do it -

http://i50.photobucket.com/albums/f3...1/IMG_7682.jpg

Easy to say since I don't have to :) Maybe it won't work if you can't pull the big bolt off the tensioner arm. If the bolt is captive, I agree the water pump pulley has to come off.

Definitely can be done on a 603 since I've never been able to get the pulley off the water pump. Unhook the spring, remove the tensioner pulley then pivot the tensioner arm so the damper clevis is at 12'clock

Sixto
87 300D

The center bolt with the 12mm Allen head is press fit into the ID bore of the bearing, that's why the water pump pulley interfers. The whole tensioner moves outward as its center bolt unscrews.

The OP should be careful and make note of any washer/spacer between the tensioner and the timing cover as things are disassembled. different years and models may or may not have the washer/spacer, and it's easy to no see it and lose track of it as you pull stuff out of there.

if you remove the tensioner pulley first, then rotate the arm so the tensioner JUST clears the crank pulley, the tensioner arm should clear both the wp and the crank pulley... but wow, that is sure a large wp pulley...

Thanks for the confirmation. The 12mm center bolt is a press fit and no way you can remove the tensioner without removing the water pump pulley. When you remove the pulley, you need to drain the radiator and remove the radiator. The list goes on and on. I then butchered up the 4 6mm allen bolts that held the wp pulley in place. It was a ROYAL PAIN in the A$$. Whoever designed it should be held accountable.

I don't understand why the radiator is removed, are you saying the fan and it's clutch can't be removed because the radiator is in the way? just looking quickly at the 601 FSM there should be 90 mm between the front of the fan blades and the rear of the radiator, that's more than 3 1/2" of space between them, more than just about any Mercedes I've ever seen!

Remove the shroud or at least release it and move it out of the way, remove the center collar screw and the fan comes off, carefully and thoughtfully remove the four Allenhead bolts and pulley should be able to be pulled off, you might be able to get the tensioner off then if it will fit past the magnetic coupling, if not unbolt the coupling from behind disconnect the wiring and that will pull off, then the tensioner should get past easily.

This serpentine tensioner is a piece of cake compared to many others, you can actually see what you're doing!

How can there be no room to get vice grips or a socket type extractor on the water pump pulley bolts with the radiator in place? Doesn't the 190D 2.2 have clearance of at least the thickness of the fan and clutch between the water pump pulley and the radiator? This looks like plenty of room, far more than in a 124.133 -

http://www.benzworld.org/forums/atta...8-dscf0471.jpg

... though the water pump pulley bolts look recessed which presents another problem.

Does the 190D 2.2 have an electric fan clutch like the 190E 2.3?

Sixto
87 300D

x2. The M103 belt tensioner is a far goofier design.

Sixto
87 300D