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-   -   190E's Critical Suspension Failure (http://www.peachparts.com/shopforum/tech-help/61697-190es-critical-suspension-failure.html)

Marsala 04-08-2003 12:23 AM

190E's Critical Suspension Failure
 
1 Attachment(s)
Hi Everyone,

When I bought my 190E 4 years ago I never thought I'd be riding in a tow truck with my car mortally wounded being me. Well, tonight, on my way home in the pouring rain that is April in Vancouver I felt something give in the right front suspension, pulled my car to a stop, and watched my spring roll down the side of the road in front of me.

Naturally my first thought was "this'll make a great story for the forum!".

I'll be printing the "after" picture to take to the Service Department to see what they can do, and for what large fraction of the car's value they can do it for. Then I'll visit the Sales Department for a new car.

Any thoughts from the experts? Cut and weld on new part? Tow it to the junk yard?

1987 190E 2.6L 216,000km

/conway.

"After" taken on 7April2002:

Marsala 04-08-2003 12:24 AM

Up Close!
 
1 Attachment(s)
someone had said this car came from colder, saltier climates..

xp190 04-08-2003 12:34 AM

I'm quite sure you can get someone to weld that for you, maybe get the rusted through piece from the junk yard, cut it right and weld on, maybe replace, but I know it would not be worth getting rid of the car completely.

worst case scenario sell it for parts, but don't junk it.

xp

williambishop 04-08-2003 04:29 AM

Just be happy you were in a mercedes when it happened.;)

csnow 04-08-2003 11:12 AM

Well, that could be a bit unnerving...

Someone had posted a picture of a tear in their spring mount last week.
I suppose we now know what happens when the mount actually gives way.

Unless you are equipped to weld, try a welding shop. They are generally cheaper than body shops, and no points for aesthetics under there. It should come out stronger than new. This is really not that bad as structural repairs go. Easy access, and limited scope.

Certainly have the other side checked, and perhaps pre-emptively reinforced at the same time.
May as well inspect the balljoints and CA bushings as well, since the spring is conveniently already out of the way!

Best of luck.

haasman 04-08-2003 12:54 PM

After the repair/welding, I would be sure and have the proper Wurth body sealer applied all over and around the area of the repair.

Haasman

Marsala 04-08-2003 08:40 PM

update (all too often people forget to post updates/solutions):

I got the digital images to Eddy Lai at AMG, so they were able to check out the damage before even seeing the car. The 190E is now in their hands with an estimated 4hrs of cutting/welding, and fortunately loss-of-use has been negated by my last-minute business trip to snowy Alberta!

Lesson Learned: keep check on rusty parts under load!
Thanks for the responses, looks like the car goes back up for sale since I spotted a few C230K/280 Sports...

yhliem 04-08-2003 08:59 PM

Quote:

Originally posted by csnow
It should come out stronger than new.
Just a tip to the rest of you: this is not necessarily true.

When you apply high temperatures to metal, as in welding, you affect the atomic structure of the metal and can actually weaken the metal surrounding the weld. Although the weld itself is quite strong, the Heat Affected Area can be considerably weaker.

Just a little FYI

williambishop 04-09-2003 02:25 AM

Quote:

Originally posted by yhliem
Just a tip to the rest of you: this is not necessarily true.

When you apply high temperatures to metal, as in welding, you affect the atomic structure of the metal and can actually weaken the metal surrounding the weld. Although the weld itself is quite strong, the Heat Affected Area can be considerably weaker.

Just a little FYI

Since they will most likely MIG it, I don't see much chance of it deforming/weakening the metal around the weld to any real extent. I think he should be fine with anything other than rally racing the car.

csnow 04-09-2003 01:33 PM

Not contesting the chemistry involved...

Metallurgy aside, welders do tend to practice the fine art of 'structural overkill'.
They are not concerned about shaving a few extra pounds or a couple bucks worth of steel from the bottom line, like an auto manufacturer is.
A couple of well-placed 'gussets' (for example) would more than make up for any structural integrity lost from heating.

stevebfl 04-09-2003 02:39 PM

Yes, this is the heart of the repair. Yhliem is right on about the metallurgical changes that take place. It doesn't matter how quick to welder is, as whats more important is how quick it cools.

In a weld every form of heat treating takes place from the hardening of rapidly quenched martensitic transformation to the annealing properties of a slow treatment. Hard and brittle to soft and pliable. But as csnow points out, metal is cheap and structural reinforcing from the adding of material to the thickening of the fractured area can easily make the end result stronger than the original clean sheet.

williambishop 04-09-2003 03:29 PM

Quote:

Originally posted by stevebfl
Yes, this is the heart of the repair. Yhliem is right on about the metallurgical changes that take place. It doesn't matter how quick to welder is, as whats more important is how quick it cools.

In a weld every form of heat treating takes place from the hardening of rapidly quenched martensitic transformation to the annealing properties of a slow treatment. Hard and brittle to soft and pliable. But as csnow points out, metal is cheap and structural reinforcing from the adding of material to the thickening of the fractured area can easily make the end result stronger than the original clean sheet.

Exactly, and speaking as a certified welder and pipe fitter from long ago(before changing careers), I don't think I ever had a repair job go bad. And if it can hold together battleships, I think the odds of it holding a spring in place are pretty good. Mercedes used good steel in their cars, mig good steel back to it, and I would be willing to bet that it will be every bit as solid as OE. Maybe not as pretty(depending on the welders skill and detail orientation), but definately as strong.

Kestas 04-09-2003 03:57 PM

All this talk about microstructural changes depends on the base metal. If it's plain low carbon steel, it's really not that tricky to weld repair using good overlapping seams. If you're working with HSLA steel, you'll run into the problem of brittleness in the HAZ immediately adjacent to the weld. It's extremely difficult for a welder to cool the part slow enough to avoid this phenomenn. This can be a serious problem on a loaded part.

Battleships are typically made from plain carbon steel.

Nobody can really tell just from looking if the part is plain low carbon or HSLA. The only clue may be how intricately drawn the part is. Intricately (or deeply) drawn parts are typically NOT HSLA.


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