Belt tensioner spring snapped - E300TD

[Parrot of Doom]

Driving home today, just a couple of miles, accompanied by the most awful belt squeal you can imagine. Nursed her home and lifted the bonnet to find that the large sheathed spring on the belt tensioner assembly has snapped clean in two, and is dangling from the engine

So, because its raining outside I can't check, but is it quite easy to get the spring back on its bottom mount? Is is a hook, or an eyelet? The lower half of the existing spring has gone bye-byes somewhere.

Something else I noticed was the metal box at the front of the engine, nearside, that appears to be something to do with the braking system - its got lots of metal pipes entering/leaving the top of the box. Its on rubber pads and one of the pads is missing. Is this just a case of lifting it up and inserting a new pad, or is there more to it?

 

[Ian B Walker]

The near side box is the ABS Module. Just for piece of mind I would replace the rubber foot. be careful when doing it. As for your belt tensioner. I have seen examples of the housing thatthe spring fits in sheared. Make sure that you have the bottom locator intact. Fraid its a little time consuming.

 

[Asif Kazani]

I recall the same from my W140 300SD that I owned a few years ago. If I remember it correctly, replacing the spring and the shock absorber did not that that long or a lot of effort. I may be wrong though since it has been a number of years. My cars bottom locator was intact and unscathed but Ian in 100% correct when he says it may very well be sheared as I too have heard of these instances.

 

[Parrot of Doom]

Had a look and thankfully it seems ok:

I reckon that will take about 5 minutes to replace.

Heres the box I was talking about:

You can see where one of the rubber mounts should be, and its missing. There is another one on the same side, other corner, thats missing as well. Any idea how its all supposed to be secured together? Do the mounts slide onto some kind of feet on the ABS box?

 

[Asif Kazani]

The bottom part where the spring is locked in has a teflon/plastic type bush. This is also evident in the picture. Make sure that there is no wear on it as depending on mileage and age, this might have gotten notched in pretty bad.
As far as the ABS box is concerned, you might want to take a look at another car or wait for somebody to reply to this thread. I shall take a look at my car and let you know. In the meanwhile, send PMs to Ian B.Walker and Dieselman since these guys seem very knowledgable and helpful.

 

[Parrot of Doom]

Are you saying that the bush is present in the picture? It seems to me as though the spring will just hook onto both ends.

The shocker, pulley, belt and mechanism are all new as of around 2000 miles ago. The spring was the only 'old' bit in there. I reckon its given up the ghost because of the undue pressure upon it when the old tensioner mechanism was wearing away.

 

[Asif Kazani]

Are you saying that the bush is present in the picture? It seems to me as though the spring will just hook onto both ends.

The shocker, pulley, belt and mechanism are all new as of around 2000 miles ago. The spring was the only 'old' bit in there. I reckon its given up the ghost because of the undue pressure upon it when the old tensioner mechanism was wearing away.

Just look at the part where the spring hooks up on the bottom, the little piece that would be the center to the hook.

 

[Parrot of Doom]

Argh, can't get a new one until Wednesday!

Good job I'm not working this week!

 

[Asif Kazani]

I looked at the ABS box today and it seems to be locked in place with the rubber mounts and not much else. I think all that is needed to put the mounts under it is little patience since I feel that the pipes may want to maintain their positions but it does seem like a simple job. Haven't done it before so can't really say much.

Good Luck.

 

[Parrot of Doom]

All sorted. I could have done a HOWTO but frankly its ridiculously easy to change the spring

Gonna sort the ABS box today.