plataman

Hi, I would like to know if there is a difference between a s430 and a s500 rear. I do know that the axles are not interchangeable but they have the same gear ratio from what I was told. Due to an accident I had to change the whole rear suspension assembly "cradle" and I replaced it with one from a S430 and that's when I realized that the rears were different.

newton22

I'm a bit confused. So you found out they were different?

plataman

okay, yes they are different as far as the axles are concerned but I want to know if the s430 rear would affect the car's perfofmance in any way.

whoover

Yes, the final drive ratio is 2.82 on the S500 and 3.07 on the S430. It will theoretically improve acceleration at the expense of top speed and mileage. But it's not the rear end that MB chose to match the torque curve of the engine, so you could be shifting at the wrong time. In fact, I wouldn't be surprised if the transmission throws codes or even drops into limp-home mode because it detects a mismatch between what the ECU and TCU think should be their operating points.

plataman

I must say thanks for responding and I have found your info to be very helpfull. I do have the original differential and recently bought two axles and is going to have them installed, I just wasn't getting the right info from some people that I spoke to regarding the situation.