Is this normal ?

[Tomit1]

Hello,
Is this normal for a 350SL -73?
With the motor running, when I keep the brake pressed and engage the trans. to reverse the back of the car lifts up maybe half inch and when I engage to D the back descends by the same amount.
I have new bilsteins, but maybe the springs at the back are worn out, or maybe the control arm bushings or maybe this is just normal.

[iwannabenz]

For what it's worth, my '85 380SL does the same thing. (I also wondered if it was "normal").

[ericdee]

Me too.

[cbdo]

I've always assumed it's normal; every Benz I've driven does it, so it must be!

[iwannabenz]

So now that we know that this is "normal", the question is WHY do they do this? I have driven many vehicles in my 30 or so years of driving, and have never experienced this before. Do other Benz's (Benzi?) do this? Just curious.

[bowbyeal]

I agree, my 1984 - 380 does the same thing. I.E., there is a slight and momentary "rise up" when beginning to move forward or back. I have talked to other 107 owners all of whom say it happens to them. I too have brand new Bilsteins which are fabulous but I still "rise up". Just think of it as a salute to Bruce Springstein. Happy motoring!

[cbdo]

Isn't that Spruce Bilstein?

But seriously, folks--noting that virtually all the MB's we drive are RWD, it's always felt to me like a function of torque applied through the drivetrain interacting with the rear suspension geometry when the wheels are immobilized by brakes. I used to notice it on Dad's 280SEL and it's been a feature of every one I've driven since. What I don't know is what particular aspect of MB rear geometry produces it. And, since I've not driven any other RWD cars in eons, I don't recall whether other RWD tend to do just a bit of it as well.

[Tomit1]

Thanks for the replies. Now I know this is normal. It has puzzled me for sometime. Good to know that all is OK

[Darrell Woods]

My '75 450SL also has a definite "squat" when I shift into drive. My wife's '89 260E does not do this at all. Since both have decent shocks and springs, I too assumed it was just part of owning a 107 (I've watched other 107s do the same...you can actually see the car sink down).

[cbdo]

It would seem that the geometry of the rear suspension from the 60's to 80's must allow more-than-usual translation of the torque applied to the rear axle when the wheels are immobilized by the brakes into vertical motion of the axle relative to the body of the car--toward the body in forward gear, away in reverse. Just off the top of my head, it seems that there's an association across models between motion on shifting and squat on acceleration; I do know that MB worked through the 70's-80's to reduce squat and dive, and that probably would translate into reducing the phenomenon on shifting at rest also. Anyone know the suspension geometry well enough to enlighten us?

[4NDELIT]

Originally posted by Darrell Woods
My '75 450SL also has a definite "squat" when I shift into drive. My wife's '89 260E does not do this at all. Since both have decent shocks and springs, I too assumed it was just part of owning a 107 (I've watched other 107s do the same...you can actually see the car sink down).

I would think that has more to do with the torque of the V8 compared to the 6 (I6? V6?). My car does that too.

[cbdo]

As far as torque goes, Dad's 280SEL did it quite noticeably, and so does a friend's Pagoda (more than my 560SL). I still think it's suspension characteristics that produce it.

for what its worth, my 78 300d also does the squat... thats not a torquey engine....

[MD2B]

My 1995 Ford Mustang GT I drove in college about 6 years ago did this. My 1989 560sl also does this. I always thought it was the torque because it is worse if you give the car a little gas while holding the car still with the brakes.
md2b

[Bill460]

The differential is bolted to the body, the torque of the diveshaft must cause the body to lower in drive or raise in reverse.