I've always been something of a contrarian. When my parents told me not to do something, I usually did it anyway. A large number of cheap Timex watches, radios, cameras and other miscellaneous items around the house came apart as I explored their innards. Some even went back together again.
One of the things people tell you never to do is take apart the seatbelt retractors. Leave it to a professional, watch your eyes etc. etc. All good warnings and advice. But if you do want to peek inside.....
Both my retractors had stopped retracting. So there wasn't much to lose. As it turns out, this is a simple repair, though there are a few subtleties to be aware of. Documented here for posterity.
First step is to disassemble the retractor. On my 1973, there are 2 black covers held on by 2 screws each. One is higher than the other, and it is under this one that the inertial reel lives. The inertial reels on my were pristine. No issue there. If there were issues, I'd recommend new seat belts. The use of oil or cleaning agents on the springs and ball bearing and the reels would alter their frictional and inertial properties. Not a good idea.
The other black cover hides a 20 foot long snake of coiled spring steel. This is a delicate operation. Remove both screws, gently lift the cover up a few mm at a time and see if you can stick a screwdriver or eventually finger under there to prevent the coil spring from exploding off. By no means should you peer too closely without safety glasses. If the spring pops off like a crazed slinky, you don't want an eyeball in the way. Don't worry if the coil spring comes off. You want to remove it, clean it and rewind it as follows.
On both my tensioners, the spring had broken at the centre hub. So I needed to cut a clean end and then remake the bends that fit in the channel in the hub. You can't just use a nose pliers to do that. The metal is brittle and you can't do 90 degree bends without breaking it. The trick is to heat it with a torch or on a gas stove and then do the bending. Run it under cold water to anneal it. The key is to put the bends in the right direction. The spring will form a natural coiled curve. You don't want to wind it in the direction of that coil. You want to do it in the other direction otherwise you won't have any spring tension.
Before you start winding anything, pull the belt all the way out. Push the inertial reel into it's locked position. I used the 2 screws from the covers to do this and taped them in place.
Put the end of the coil spring with the U shaped end in a vice and stretch out your coil. This will involve a lot of cursing. Try not to kink the coil spring as it won't roll and unroll smoothly. Now place your new end with the proper bends into the hub and make sure you are winding it around the hub so that there is tension and the coil wants to curve away from the hub. Keep constant finger pressure on the coil as you twist the whole assembly to wind the coil spring onto the hub. Keep tension on the whole coil spring length or it will want to coil up and kink. Attached is a picture as I got close to the vice. Note that I'm still pulling the whole retractor assembly to keep tension on the remaining length of coil spring so it doesn't twist.
Hook the u shaped end as shown and then take a break. Your fingers will be cramping from holding down the coil as you rotated the whole assembly winding the coil on the hub. And you probably had the whole thing spring loose 3 or 4 times while you were doing this and you had to start over. It's the equivalent of winding 80 feet of spring steel on a 1" hub by the time you get done ! So really, relax for a bit. However, put a rubber band or something to make sure the coil doesn't pop off while you are taking a break. Until that point, you should be keeping finger pressure on the coil the entire time. Double check you have the right winding pattern, as shown in the pictures below.
After you have regained your composure, note that the pretty, tight spiral you have wound like above will not actually work. It's too tight and the coil can't expand and tighten freely. So, keeping firm pressure on the coil, you need to unhook the u shaped outer end and let it uncoil in the plastic holder by about 3 turns and hook it back up. Basically you are removing some tension. Keep firm pressure on the coil. One slip up and you have to start over. Now undo the tape that you used to hold the inertial reel locked in position, while still keeping your fingers on the coil to prevent it from jumping out. The reel should retract the belt. Your nice tight coil will now look like this. Note how the coil is still tight at the outer circumference but more like a watch spring in the middle. Note this is the other side retractor from the picture above, so don't get confused.
Now put the covers back on. Coil side first. I left one rubber band over the coil as I did this so it wouldn't pop off. Make sure the rubber band goes over the middle (i.e. the hub). That's the part that most often wants to pop lose as it is under the most tension. Once I got the cover on and turned one of the screws a couple of turns, I pulled the rubber band out. The cover prevents the coil from springing out if you don't lift it too high.
That's about it. Took me 4 hours to do the two front ones. The coils jumped out a total of 3 times on one side and 7 on the other. Your fingers will get tired. You have been warned !
Everything works great and once Dave's labels get here, they get sown into the now washed belt webbing.
cheers
Ravi
DISCLAIMER: Don't do this. If you die because your belts failed, remember, I told you not to do this.
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Originally Posted by NorthernThrux
