Both rear seat belts roll back up weakly. One is so bad I'll have to take to dealer. Anyone else have this problem?

At dealer now, I'll see what they say. Only one doesn't roll up well.

Well, extended warranty did not cover. Dealer replaced seatbelt assembly with tensioner (rear pass. side). Cost $575. Ouch

Ouch is right! I have the same issue on the right rear passenger side of my ML350 2010. I'll buy the tensioner and either have my independent do the work or handle it myself. That's just too much money.

He told me the part(s) alone were $230 and that was at their max discount. I watched the tech a while and he had to climb in the backseat & rear cargo area and pretty much remove all the interior trim on that side to get to it. Didn't look too easy. I like doing things myself, but would pass on this. I'm guessing an Indy would charge $400?

I have 2007 ML same issue right rear seat belt won't roll up.

My 08 ML550 has the same issue on the rear drivers side.. I was goint to attempt replacing myself but not so sure now..

Anyone do this as a DIY on an ML? I have the seat belt issue and my vehicle is less than a month out of warranty. I would like to tackle it myself if I had some instructions. Thanks in advance.

I'm in the exact same boat with my ML63 AMG. The right rear belt was slow to retract initially. I was forced to manually 'yo-yo' it back in, a few inches at a time. Condition worsened. Now, I have roughly ten feet of belt laying on the rear seat, unable to do anything with it. Coincidentally, the left rear seems to be 'sticking' a bit now too.

I've searched multiple MB forums. Though I didn't find any ML63 brothers with the same prob, I did find many posts of MB owners with this issue.

I spoke with the dealer. His obvious knee-jerk response was "new belt assembly, $7-800".

I've opted for a different approach. I found an on-line vendor that restores/repairs/resets seat belts for all MB's. After removing the effected belt, you ship it +65.00 to their shop. They restore/reset it and ship it back. They're claiming turn around time of 1-2 days. They pay for return shipping.

I haven't pulled the belt out yet and don't know degree of difficulty here. I did just order some nylon interior trim tools to help get the trim/pillar panels off. Hopefully, someone has been down this road and can help us all out. Seems like a great DIY idea for the forums, as the savings here is huge.

I'll keep ya posted on my progress...or lack thereof.

Brad.

This was posted by StoneTheCrow on the benzwold forums. See thread here: http://www.benzworld.org/forums/w164...t-retract.html

Rear Seat Belt Won't Retract DIY fix

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I had the same problem on my wife's 2009 ML350. The left rear passenger seat belt would not retract. As mentioned by other members, the dealer wanted several hundred dollars to replace it. I believe they quoted around $800 in 2013. I checked around the internet to see if there were any federal or state (AZ) regulations requiring a free fix but found that if the vehicle is no longer under warranty it is up to the owner to pay. A local salvage yard quoted me $100 for a belt off of a 2006 or 2007 model. I'm fairly handy and cheap so I figured I'd dive in..

From the trunk area I removed the black tie down brackets with a torx bit (3 brackets I believe) and then carefully started popping off the edges of the larger vertical black panel by cautiously pulling/prying. I did this all the way along its top edge towards the back seat and even pulled back the weather stripping around the passenger door to expose a couple of more metal clips which can be disengaged with a flat head screw driver. This gave me access to the lower edge of the white panel that the seat belt retracts through. There are a couple more torx screws along its bottom edge that I removed, including the one under the "AIRBAG" pop off cover along the white panel's upper edge. This freed up the upper portion of the black panel and lower portion of the white panel. It may even be possible to complete the project without freeing up the lower edge of the white panel but as I wasn't sure, I did this to give myself more space.

Anyway, once I could see the belt mechanism I removed the soft rubbery cover from the belt mechanism to expose the retracting/coiling mechanism. The retracting/coiling portion appeared to slow up once more of the belt wound in. I simply sprayed some WD40 and some Liquid Wrench (ran out of WD40..) between the spinning portions and it's bracket and ran the belt in and out over and over. I figured I'd overkill it by adding a tad of all purpose grease between the wheel and bracket. Ran it in and out a few more times and worked like a charm! Took maybe an hour and saved myself (and hopefully you) a few hundred bucks and trips to the dealer! Hope this helps someone else out.

Thank you!! Excellent info! I haven't attempted this DIY yet, as it's friggin' freezing!!! here in Montana currently, but am anxious to get going on it. I think I may still have to send the right one in to be reset/restored, as the belt is completely extended and I can get it to retract at all.

There is also a YouTube video available. It's not particularly well done (eg, poor lighting and focus) but helpful. I did this yesterday and managed to get to the retraction device but getting lube (WD 40-type spray-on lube) in there was quite challenging. I would recommend finding or making an extra long "spray tube" in order to better direct the lube, since it will likely be difficult or impossible to get the can of lube any closer than about a foot from the parts where you'll be spraying (see "nilknarf" above). I used some packing tape to tape two of the 4-5 inch (red) WD-40 spray tubes together to get one twice as long; i think you can also buy these longer spray tubes. Mine now seems to work better but i don't know if it will work in a hard braking event; which is, of course, when it is needed.
I suspect that the better solution is to pull the retraction device and send to be reconditioned and reset...but i couldn't get good enough access to "pull it".