seatbelt help - PeachParts Mercedes-Benz Forum

gatorblue92 · #1 05-06-2011, 04:56 PM

For about the last 10-15 years the rear driver side seatbelt in my 240D has had an issue extending. Whenever you attempt to pull it out it will lock up. I haven't ever fooled with it until now since I haven't needed both rear belts but with the impending arrival of son #2 i will need it for a car seat. Has anyone had any success repairing the seatbelt or should i just get a new one? If its necessary to replace where can i get one?

Stevo · #2 05-06-2011, 05:24 PM

Maybe one from a wrecking yard would be the way to go. I would think a back seat belt is not a highly sought after item so there should be plenty around if yours is not an easy fix.

vstech · #3 05-06-2011, 06:07 PM

beware and use caution working on the seatbelts.
some models have explosive charges in them to retract in the event of an accident.

that said, on my 79TD the rear belt would not work, similar to your problem. I found rust on the tensioner teeth, and such. I tried cleaning it. gave up and replaced it.

leathermang · #4 05-06-2011, 06:12 PM

With high water heading your way you do need to get that fixed.... and think about adding a floating safety device , like a boat, to the backseat....

gastropodus · #5 05-06-2011, 09:03 PM

You'll find that the junkyard pick'npull will have a lot of these retractors that will potentially fit your 240D. I think that I got my replacements from a 300D, in fact. Check carefully on one thing, however: at some point during the years they changed the shape of the buckle. If you're getting a full set out of the donor car it's not such a big deal, but if you're just grabbing a belt and retractor it has to match the receiver part of the buckle in your car.

I took pictures to document the process of replacing these; maybe I'll get around to posting the DIY in the body section of the forum tonight.

Kurt

1980sd · #6 05-06-2011, 09:29 PM

Quote:

Originally Posted by vstech

beware and use caution working on the seatbelts.
some models have explosive charges in them to retract in the event of an accident.

You jest...

Lycoming-8 · #7 05-06-2011, 10:44 PM

No jest at all. Mid 1984 and all 1985 D and SD for sure. Probably some others after that!?!

vtmbz · #8 05-07-2011, 06:15 AM

Dont try to repair a seatbelt retractor. Bolt in a complete replacement only, and make sure to use the correct bolts and washers. IMHO

gatorblue92 · #9 05-07-2011, 08:43 AM

Looks like I will search at the pull a part next time I go. There is a 300D there that was in fairly good shape last time so hopefully the seat belt will still be there.

vstech · #10 05-07-2011, 10:01 AM

Quote:

Originally Posted by 1980sd

You jest...

ABSOLUTELY no jesting involved!
an explosive charge is built into many 123 and up vehicles' seatbelt retractors to PULL you back into the seat in the event of an accident. having one explode in your face would be a very bad thing.

Stevo · #11 05-07-2011, 10:31 AM

Quote:

Originally Posted by vstech

ABSOLUTELY no jesting involved!
an explosive charge is built into many 123 and up vehicles' seatbelt retractors to PULL you back into the seat in the event of an accident. having one explode in your face would be a very bad thing.

Thats good too know

10fords · #12 05-07-2011, 10:41 AM

Quote:

Originally Posted by vstech

ABSOLUTELY no jesting involved!
an explosive charge is built into many 123 and up vehicles' seatbelt retractors to PULL you back into the seat in the event of an accident. having one explode in your face would be a very bad thing.

I had never heard of this until now. Where are the charges located? In the B pillar? Are they present in the rear belts as well? What years/models had them? Sorry for all the questions, but I would like to pass on this info at my next vehicle extrication class as it has been generally said that no SRS devices were used until early 1990's. There are a lot of 123's around my area and the possibility of having to use the jaws of life on one, either in a drill, or in an emergency extrication, are very real so this would be great info to have. Thanks-Scott

Edit- I just looked in my FSM for the 126 series and it appears that they had them as early as 1982, and airbags as well. Only in the front from what I could gather. They are called ETR's (emergency tensioning retractors) and are located in the belt tensioning unit inside the pillar. There is a whole section on location, testing, etc. I also looked in my FSM for the 123 series and there was no mention of any sort of SRS- airbags or ETR's or anything else. I should also note that the FSM indicated that the ETR was not strong enough to pull you back in your seat, it would just keep you held securely in an accident.

vstech · #13 05-07-2011, 11:22 AM

http://www.youtube.com/watch?v=EqMEGA76HsE
this is an early w123 crash test video, complete with seat belt retentioning action, air bag deployment...
obviously all devices were not present on every 123 produced, but this is video proof that they did put them in some vehicles... if only for testing.