Broke a Coil Spring - 87 300D Turbo - PeachParts Mercedes-Benz Forum

a2t · #1 09-15-2006, 09:24 PM

Well, finally got it repaired.

Had to order the spring new, and when I got it and saw how massive it was -- looks like a locomotive spring - I decided to let the experts wrestle with it.

Glad I did, they said it took 5 guys better part of afternoon to get busted coil out and new one in.

That tool is very tough to use. Problem is, it BARELY fits between coils all the way extended (to slide in the end plates). And all the way extended means the coil is in an arc. So the tool dont fit up through the middle.

And if u compress the coil by jacking up control arm, you cant slide end plates between coils. I couldnt figure it out, and I work on VW's almost for a living.

And you guys werent kidding, you would need to compress about 8 coils flat before it would come out / go in. I thnk the shop ended up dropping lower control arm and spindle. No thanks, $100 WELL spent.

I'll post pics of broken coil, I have never seen something this massive shear like that. Must be a heavy car...

Johnhef · #2 09-16-2006, 10:10 AM

Wow, I'm surprised it took that many of them that long to do it

Now mine wern't broken but I went to install the H&R springs last night, just did the front and it made the car sit too low- had to put the originals back in- all in about 1.5hrs.

t walgamuth · #3 09-16-2006, 11:45 AM

the cars really are light for their size and strength.

lightness is expensive... how much can you afford to add.

as colin chapman used to say...."not going fast enough?...add lightness."

benz springs are very very high quality. i have owned 29 of them and driven or my family driven maybe 4,000,000 miles in them. i have never had a broken one. i have replaced a very few which had settled. i am thiniking of my 74 240d which had an auxiliary tank fitted from the factory so it was perpetually overloaded.

good work!

tom w

psfred · #4 09-16-2006, 03:02 PM

That long, fairly low rate spring is classic European suspension design philosophy: supple, low rate springs considerably compressed allow easy wheel movement, controlled by shocks and sway bars. Upward wheel movement is permitted, downward wheel movement is greatly restrained.

The result is the classic Benz "glide over the bumps" ride combined with quite good handling for such a smooth ride (they aren't sports cars, after all!).

This combination permits much greater tire contact time on rough surfaces (i.e. cobblestone roads) and is one of the things I like best about Benz.

American suspension philosophy seems to be make the shocks as stiff as possible to prevent body roll (no sway bar) and use high rate, short springs lightly compressed. That results in wallowing behavior (watch a 70's Cadillac on a road with lots of dips in it) and bone-jarring collisions with the far side of potholes and projections from the road surface. Greatly improved by installation of Bilstein shocks, by the way.

American designs (mostly Asian and European by now anyway) are improving, but still behind the times.

Peter

a2t · #5 09-16-2006, 10:12 PM

Agreed. Benz has a great ride.

Weird thing was I tried to do the work myself, but like I mentioned, couldnt get spring compressor through the inside of spring in car since the coil curves with the arc the control arm sweeps. I also tried lifting up the control arm with a jack to get the spring to sit vertical, but then the coils were too close together to get plates between them..

Shop had same issue, so I think they were forced to use other means (ie, removing lower control arm). Maybe you are supposed to bang the plates in there with a hammer, but I borrowed the tool so I didnt want to screw it up (not to mention bang on a broken spring with 1,000 lbs of compression behind it

).

Best $100 I ever spent.