96 SL500 Auto Trans 3-2 downshift clunk

[jes007ser]

The Problem happens 2 out 3 times.
When coming to a stop the transmission will clunk as it downshifts from 3rd to 2nd gear. Has anyone had this problem and if so what was the fix?

[ASEMAT]

Hello Sir, Yes I am familiar with this problem.

Mercedes-Benz repair is my way of life. I am the superintendent of repairs at a dealership in Southern California. Although what I will say might sound "trained", it is because I am very trained. I am trained for you to know the absolute truth concerning your vehicle, and to inform you in the most respectful way I possibly can, sir.

Although I cannot diagnose your vehicle over the internet and the only proper way to diagnose would begin with a test drive. I can note to you an inherent area of concern with your 96 SL500. The most likely event that has occurred is a fault in an area that sounds to be coming from the transmission but is not. LOL many of techs, even myself with over 20 years experience with this model have been fooled. The noise usually begins to happen during decelleration by cruise control downshift or just simply slowing for traffic from 3rd gear to 2nd due to a dampened delay in the valve body which tightens the band around the planetary set. The transmission itself cannot make such a sound by how it is built. The clunk sound you hear emanating is just post of the tailshaft at the DRIVE COUPLING. Not to fear though, this is not very expensive part, and it was put in as a sacraficial part of the design, and every roadster like yours has one that eventually sacrifices itself in order to prevent punishment to other crucial and more expensive hard parts.

Your drive coupling can actually take many more miles of regular driving in its current condition if it had to, however, the fine balance of the drive train has been effected to some degree and Mercedes-Benz suggests that when drive couplings begin to clunk, that they should be replaced in a somewhat timely manner. The best place to have your vehicle serviced is a Mercedes-Benz dealership by trained personnel. Each repair facility has at least one person whereby their experience with drive couplings is so great, that by looking at them they can have a good idea of the condition of the rest of the drivetrain. Drive couplings you might say provide a tell tale of what is up with the rest of the drive line,and it is his or her life per se to know the patterns of wear, and so on.

You are of course at the liberty to take your vehicle wherever you please, or perhaps even do the repair yourself. If I may make one suggestion to you that is of paramount importance regarding your vehicle:

The part itself. The drive coupling. Please be absolutely certain that it is a genuine Mercedes-Benz part. This is essential for the continued reliable service your vehicle can provide. Their are many pseudo parts out there that are merely shadowed replicas of the original. This applies especially to drive couplings and engine mounts. The only way to be absolutely certain is to buy your part from an authorized Mercedes-Benz Parts dealer. As said, they are not that expensive either. Wishing you continued enjoyment of your 96 SL500, a most excellent vehicle. Sir, Did you know that even though your vehicle is a roadster, the 129 chassis happens to be one of the most stout and safest vehicles on the road! Wishing you many more miles to go!