amstel78

Saw this thread, but rather than reviving a dead thread decided to post my own.

Trunk on my S65 opens and closes OK, but when closing, it tends to slam the trunk lid down rather then gently closing it. Is that the way it's supposed to work, or is something out of whack and requiring adjustment or calibration? On the other hand, if I ride the trunk down with my hand so as to not let it slam, the trunk's soft close feature works fine. Additionally, the partial trunk open feature does work as well which leads me to believe the angle position sensor is working OK.

Perhaps a mechanical adjustment somewhere is required?

ETA: trunk struts are new. I replaced them after the trunk lid tried removing my head once.

tusabes

The hydraulic trunk lid closer does tend to slam the trunk shut

cmpcpro

Hmmm.. mine doesn't slam at all..

TNJohn

My 2006 S500 does a "slam shut" on closing, too. I am happy it closes, so I haven't pondered if that is normal, lol.

As an aside, Mercedes put close assist on the Pullman cars, the 600 SEL, from the late 60's through the run of the car. It was hydraulic, quick in action and rather unforgiving to objects in the path of closure. I have heard from old mechanics that fingers have been broken or even severed! The good old days weren't always good

John

amstel78

Hi John, I'm glad mine shuts too which is why I didn't think much of it until I was at the dealer. I watched someone close their trunk on a W221 and it didn't slam shut. It stopped just short of closing, with the soft-close mechanism going the rest of the way. I started thinking about it, and the fact that our cars have a soft-close feature in the trunk, made me question why my lid was just slamming shut. Can't be good for the latch mechanism either in the long run.

TNJohn

I would like to know what's involved to restore the soft close. I can't imagine harm coming to the latch mechanism with the firm close, but if it was designed to soft close, I'd like it back

DrDoe

My trunk slam shut too and I didn't think of it being abnormal. LOL.

Welwynnick

If the trunk is slow to open and quick to close, it's quite likely due to a weak pneumatic strut or two, which leave too much weight on the hydraulics.

Nick

cmpcpro

Mine has brand new struts and it doesn't slam close but it closes just fast enough to close without the soft close.

wallyp

I find it hard to believe that MB would consider "slamming shut" normal operation.

amstel78

I replaced both struts with new ones when I got the car as the old ones weren't holding up any longer and the trunk tried to take my head off. The trunk opens relatively slowly, but not agonizingly so. To be honest, I don't have anything by which to gauge the opening speed by but it doesn't seem abnormal to me. It does shut quickly after the lid swings past the halfway point or where the height limiter would usually stop the lid from going any further. This is why I was wondering if there was some sort of mechanical adjustment required.

ETA: I'll take a video later on and post it. You can see exactly what I mean.

cmpcpro

Perhaps it's low on fluid or maybe the motor is getting tired? The assist trunk is something I've never really dug into but I could imagine it getting weaker after ten plus years of lifting and lowering that trunk..

amstel78

I'll check the fluid next, although not quite sure where to look in the trunk. Can you please tell me where it is?

Never mind... I googled, and the reservoir is by the battery under the foam.