rear seat belt repair/replacement 300TD wagon

[atmacg]

The inertial reel mechanism is not retracting the belt fully. I would be grateful for advice on how to remove the trim to access the inertial reel mechanism at the upper end of the lap sash belt. I don't want to break any clips on the back of the trim (located above the corner of the rear squab). I have searched the site and can't find anything on this.
Any advice on the possible fault would also be appreciated. The seat belt webbing looks OK, so I don't want to buy a new assembly if I don't have to.
thanks Andrew

[atmacg]

I should have included the model. Its a W123.
Andrew

[charmalu]

Bump

someone has to have one of these 123 TD`s.

Charlie

[jay_bob]

Before tearing the car apart, try this trick:

Check the top piece that the belt slides over before going behind the panel. Over time dirt and grime transfers from the belt to the sliding piece and it cause the belt to hang up. Clean the top piece and see if it helps the belt performance.

Most 123s do not have the ETR (emergency tensioning retractor). But if you have a late 123 with driver air bag, then beware you will probably have this. In this case you need to disconnect the battery and wait 10 minutes before removing the red connector from the ETR. The ETR will be a 6 inch long cylinder on the reel assembly. It has a small pyro inside that releases spring tension and sucks the belt in tight during airbag deployment.

[vstech]

UM, I think most 123's DO have the ETR... it was one of their big safety points selling the car.

if Jay's advice doesn't pan out, (often the wagon tensioner fails due to rust on the ratchet mechanism, preventing retensioning... the trim is all straight forward to remove. use good judgement and just start taking things apart. it'll all come out.

[vstech]

a bit of advice though... if it's rust that's gotten to the belt, pull your rear quarter window... and fix all the rust under it.

[atmacg]

Thanks for the advice. Apologies for the delayed reply but I am away from home.
The belt is moving freely over the guide. The car is a 1981 RHD delivered in Germany then brought back to Australia. No airbag, no turbo. I'll prod and poke further when I return home later this week, but I still lack confidence on removing the trim. I broke clips on the rear trim in a 240D saloon trim recently when I had to remove the rear screen to weld up some rust and I don't want to repeat the mistake.
Thanks again, Andrew

[Lycoming-8]

I am fairly certain that the ETR device or explosive charge was only applied to some of the W123's, namely some (late ?) 84's and likely all of the 85's. I ran into this when swapping seats from an 85 into an 83 W123, and quickly found that the buckles and latches were not interchangeable. Upon further digging, the presence of electrical leads and the charge device was also noted on the 85 set-up. I suspect that the buckle change was done to make sure parts from the older systems could not interchange with the ETR equipped ones.

Thankfully the car had been powered down for quite some time when I was digging around, as I was not aware of the danger at the time. The 83's belt systems very definitely did not have the device. This was all discussed some three to five years ago, but not recently.

[atmacg]

At last I have sorted the problem. Removing the trim to access the belt mechanism was done by laying the rear squab down and removing the latch trim on the interior wheel arch. A single self tapper had to be removed, then the latch trim pulled off. The rubber pad in the centre was left behind. To remove the C-pillar interior trim, unscrew the two small securing bolts (8 mm heads) at the rear of the trim which are accessed by folding down the cover over the jack storage in front of the tail gate. Then push outwards on the bead trimming around the edge of the door opening to expose the edge of the C-pillar interior trim. There are two push in clips. one at the top of the panel and the other approximately at one quarter of the distance from the front along the lower edge. A straight gentle but firm pull outwards directly towards the other side of the car now release the trim panel and all will be revealed.
I did not need to remove the seat belt mechanism - the problem was now obvious. It was a 180 degree twist in the belt at its bitter end, which prevented the belt from rolling up evenly and retracting fully. The problem could not be seen or fixed without removing the C-pillar interior trim. A photo showing the two clips is attached.