W202 rear suspension puzzle

[spock500]

Hi all,

Went to change my rear shocks today after noticing a small oil puddle which looked like tranny fluid under the spring/shock area.

When I took the wheel off I saw this:

I immediatley checked inside the boot (trunk) to see if anything had leaked through but nothing that I could see, my other thoughts were that this is oil filled?

Any ideas


Thanks,

David

 

[stevesey]

Overfilled diff, venting oil though the vent on top? (Guessing - but it's the nearest source of oil)

 

[spock500]

Overfilled diff, venting oil though the vent on top? (Guessing - but it's the nearest source of oil)

Nope, diff untouched, did the tranny about 2 months ago but its dry all around the area, bit like one of lateral thinking things

Heres a reply I received on anothe mb forum;

most mercedes bushings are filled with oil. The rear subframe bushing in your 202 could be oil filled and possibly leaking. I know all engine mounts and most control arm bushings are oil filled.


Problem is I cant find them on the mb database -

 

[spock500]

Found this - I think its one of these and they could be just rubber by the looks of things

 

[television]

They do look to be oil filled by the picture

 

[230K]

Hi

The front of the rear subframe bushes are oil filled. I confirm this. Although they dont hold a lot of oil.

230K

 

[spock500]

The oils have it

When I get the head back on next week will reverse back onto the ramps and whip one off -

Thanks,

David

 

[grober]

I would be surprised if they are oil filled but I,ve been wrong before. Bushes normally derive their elasticity from the material they are made from rather than any internal fluid. The rear suspension bushes have 2 functions-one to reduce vibration to the body and two to reduce the point loading between the 2 assemblies- subframe/body by increasing their mutual contact area. I would suspect your "fluid" is a water hydrocarbon emulsion - there are drainage channels in that area?
The engine mountings are fluid filled as you say but they perform a slightly different function . Ask Ian B Walker he's had to burn some stubborn ones out of a subframe.

 

[spock500]

I would be surprised if they are oil filled but I,ve been wrong before. Bushes normally derive their elasticity from the material they are made from rather than any internal fluid. The rear suspension bushes have 2 functions-one to reduce vibration to the body and two to reduce the point loading between the 2 assemblies- subframe/body by increasing their mutual contact area. I would suspect your "fluid" is a water hydrocarbon emulsion - there are drainage channels in that area?
The engine mountings are fluid filled as you say but they perform a slightly different function . Ask Ian B Walker he's had to burn some stubborn ones out of a subframe.

I did wonder why they would be oil filled, the only thing I can think of is a large oil spill I had in the boot when I was converting the car to run on svo, but this was back in Oct last year - it could have pooled I guess and then decided to leak as the temp got warmer?? and it didnt look like red tranny fluid ??

I have printed off both pics and will take them into Euro part ask for the part, if oil filled will buy if not will go to the pub instead :bannana:

 

[Ian B Walker]

My comments for what they are worth. I know as a certainty that the sub frame mounting bushes on a 124 are rubber only. i.e. not filled with oil. 202 bushes I believe are exactly the same and it would not surprise me if they were interchangeable, or the same part number. Having read earlier on in this thread someone suggested that engine mounts are oil filled. Sorry but they are not. They are pneumatic.

Off to the pub with you and save yourself £60 plus and a nightmare of a job dropping the subframe

 

[Diesel Benz]

It is a long time I've had to work with these, on a W124 when it was first asking for some repair, or we thought so. No experience then but a very experienced MB workshop expert elsewhere confirmed that these parts are oil-filled on a W202. Could it be that the parts are still interchangeable?

I guess one would not even need to notice if the parts are filled with oil but I'm sure Ian would know it, the comment just was more on a W124 and I was wondering if it could be different for later models.

I also had a look at MB documents but did not find any explanation about the purpose.

 

[snooz]

hello - new to this just joined - i recently traded my c200 sport (1997) for a C270 cdi (2001). When i got it home form the dealer (not a merc specialist) ive noticed a "twangy" noise from the rear of the car when i turn right into a gradient, i took it back to the dealer (as its on warranty) he told me it was the boot springs and surround them in foam?! i did this and the noise is still there - can anyone advise please? the noise is sometimes worse than at other times and it doesn't always make the noise - im about to become a dad and want to know the car is safe to drive, to me it handles and drives great its just this noise, please help, i want to go back to the retailer to be able to tell them what i want them to look at - many thanks

 

[grober]

Can't see it can be the boot springs since they are held in tension when the boot lid is shut? You might have a broken rear spring-quite common in these days of speed humps. With the assistance of a friend try rocking the rear of the car up and down on the springs to see if you can hear the sound. Then jack it up high and remove the rear wheel and have a look at the rear spring [tend to break where they sit on the suspension arm] and shock absorber to check for leaks. Do both sides but check the nearside(left looking forwards) first as that's the side loaded up when turning right.

 

[snooz]

thanks grober - think i may have problems with the retailer - if i bite the bullet and take this to a merc dealer if your diagnosis is right what kind of cost am i looking at, thanks for your help with this.

 

[spock500]

thanks grober - think i may have problems with the retailer - if i bite the bullet and take this to a merc dealer if your diagnosis is right what kind of cost am i looking at, thanks for your help with this.

I would do your own visual first, it may save you ££££'s

As with my situation above what appears to be straight forward ie... "its your shocks" turned out to be something else, taking this to a mb dealer would have cost a fair bit to be told we can't find anything wrong.

If you have axle stands jack the car up at the back and remove a rear wheel - you can see a whole lot of the sub frame, shock and springs.

Also check someone hasnt left something in the wheel well rolling about, those things can really echo

 

[grober]

Well the springs are relatively cheap and its always best to replace both to give a level aspect to the car side to side. Its the MB labour rates that are very high. Your best bet is a good independant Mercedes specialist or a good independent MOT testing local garage. They will probably give your car a quick check it for you for free if you indicate they will get the job of repairing it for a reasonable price. If the car is under warranty you should ultimately be able to recover the cost.

 

[snooz]

is the car safe to drive temporarily with this problem, obviously ill take it easy? thanks.

 

[230K]

My comments for what they are worth. I know as a certainty that the sub frame mounting bushes on a 124 are rubber only. i.e. not filled with oil. 202 bushes I believe are exactly the same and it would not surprise me if they were interchangeable, or the same part number. Having read earlier on in this thread someone suggested that engine mounts are oil filled. Sorry but they are not. They are pneumatic.

Off to the pub with you and save yourself £60 plus and a nightmare of a job dropping the subframe

Ian

The front bushes on the rear subframe are defo oil filled. When i changed mine i had to butcher them apart to get them out and both "burst" and let their oil out. Looking at his pic that seems to be the rear rear bush. These are maybe not filled with oil i have never changed them to know. But fronts of a 210 are oil filled.

230K

 

[grober]

is the car safe to drive temporarily with this problem, obviously ill take it easy? thanks.

Lots of people drive around with broken springs blissfully ignorant till MOT test time. It depends on where the break is --if its close to the spring seat on the wishbone that's OK-ish. A break 1/2 way up is more likely to cause problems but the car will probably visibly sag to one side. Is it safe to drive-well I wouldn't be driving faster than 40-50 and no hard cornering. A long trip by high speed motorway driving is certainly not advisable but a short low speed journey to a garage to get it checked out would be OK. Avoid speed bumps or anything that would cause full suspension articulation. In the end its your call.

This is assuming your problem is a broken spring of course.

 

[snooz]

that's good advice thanks grober - im speaking to the retailer again tomorrow if he is difficult i may avoid the high MB labour costs and take it to a trusted MOT provider to look at/repair, even if it costs me a bit im just looking for peace of mind before fitting that new baby seat! cheers for the help today.