New seat belts in a '72 220

[d7fresh]

I recently bought my grandmother's 1972 220 (making me the second owner). While it's in fairly good shape, there are a few things that need attention. One of those things was the condition of the seat belts. The front, non-retractable 3-point seat belts were frayed and probably would not be of much help in the event of an accident. The rear non-retractable, 2-point seat belts were fine, but we wanted to upgrade to 3-point belts as we wanted to put a car seat in for our daughter. After searching this forum (and others), I decided to do the following:

Front Belts
I ordered new retractable, 3-point belts from MB (115 860 42 85). These were not cheap, but they were worth it as 1) they look good and 2) they fit well. While I could secure the lower and upper mounting points where the original belts were anchored, there was not an existing mounting point for the "retractor". However, I found a solution.

I removed the panel covering the B-pillar and found a hole through the panel that was still covered by the vinyl. This hole corresponded with a large hole (approx. 1" dia.) in the B-pillar. I fabricated some simple brackets from 3/4" wide, 1/8" thick steel. I threaded the small hole in each bracket. I then drilled a hole through the B pillar to allow a small machine crew to pass through. I then stuck the bracket through the large hole and secured it with the small machine screw (apologies for not taking a photo of the bracket in place). I cut a small slit in the fabric of the B-pillar panel and then put it back in place. I put it all back together and found that I had just enough clearance between the seat and the retractor.

Rear Belts
As far as I can tell 3-point rear belts were never sold for the W114. So instead of experimenting with expensive MB belts, I opted for Beams. I ordered two retractable, 3-point belts and one conventional, non-retractable belt for the center seat. As with the front, there was no stock location to mount the retractors. There was also no obvious place to mount the upper part of the 3-point belts. However, upon further inspection, I found threaded mounting points under the rear deck that were not used. There were also not visible from the top, but a quick poke with my awl fixed that. The threads were the same size as the other seat belt mounting points, so perhaps this was were MB intended them to be mounted after all.

The retractors were the hard bit. In the end I decided to mount them behind the upper rear seat cushion. I drilled through into the trunk and bolted them in place. I then carefully cut part of the rear deck panel to allow the belt to pass through. I had just enough room to fit the upper rear seat cushion back into place. I bolted everything in place and the end result is shown below. Apologies for not taking photos during the install, but I wasn't sure it wasn't going to work.

While I'm 100% happy with the new front seat belts, the rear belts aren't perfect. The position of the rear retractors and upper mounts cause the belts to rub against the rear deck quite a bit. While there is no risk of wear to the belts, there is a lot of friction, which means that they don't retract very easily when you get out of the car. It's annoying, but they do provide a greater level of safety than the original 2-point belts. Also, we can now secure our car seat for our daughter.

Additional photos in the second post . . .

[d7fresh]

Remaining photos . . .

[barnumlives]

i, too, have the non-retractable belts in my 1972 220d and would like to upgrade. the ones i've acquired from the local pick 'n pull all have a long metal mounting tongue that doesn't match up to the existing threaded hole in the side of the floor pan (front seats). rather than drilling/threading a new hole i've held off making the change.

two questions on your install. the reel looks like it would rub against the side of the seat, does it? what is the dealer price for each of the two front 3 point assemblies?

thanks for your help.

[carnut]

On my 72 108 I used belts from a 80's Ford Ranger for the front. In the back, I got rear shoulder belts from a 116 chassis. The holes were in the speaker shelf already.

[d7fresh]

@barnumlives, the reel is very close to the side of the seat, but it doesn't rub. The front belts were about $500 for the pair, including shipping. The new bolts that came with the belts fit right in the existing threaded holes, although oddly enough, the old bolt heads were 11/16" and the new ones were 17mm. I highly recommend this upgrade; I always hated the fact that the old ones didn't retract.

[daidnik]

Your pics and findings are interesting. My '73 220 also has those funky 3-point belts where you had to additionally hook one of the belts after clipping the belt. Functionally good safety-wise but very funky in practice.

More relevantly though, what I find interesting is that my '73 had not only 2 different retractor reel mount holes (one low & one high) in the B-pillar metal frame cover as well as the hole for the shoulder harness slider higher up, but also had welded-in thread inserts for either a 10 or 12mm bolt. The holes in the metal frame of the B-pillar cover were covered with vinyl, but all I had to do was select the mount for the retractor reel and cut out the vinyl for the thru hole. I think I did also have to drill a hole in the cover for the peg that keeps the square Klippan retractor from moving about the single bolt mount, but that was it.

Regarding the matter of the rear 3-point retractor belts, I can say that some W114 & W115 cars DID indeed have these installed and they used a retractor reel that looks almost identical to the ones used on the B-pillar, except that they are made to be mounted on the rear deck so the weight setup to lock the retractor under sudden extreme acceleration is mounted inside the mechanism in a direction orthogonal to the B-pillar model. These rear deck retractors also had these big rubber covers that slip over the whole retractor to make it look nicer up there on the rear deck.

I have used this these on both my W115 '73 220 as well as a '68 W108 that I had earlier. Both of these had the thread inserts welded into the rear deck; I'm pretty sure the thread is M12x1.5 or M12x1.75.