I found this on another Toyota board and was wondering if anyone here had or is willing to attempt it on their T100. It sounds like it might fix the non-retracting seatbelt problem. I have always wondered about doing this but never got around to trying it. Here's the text from his post:

Posted by Josh Carlson on October 29, 2002 at 18:58:37:

It only took about 15mins. Remove the 14mm bolt and unhook the plastic housing. Now unravel the entire seatbelt from the holder. The trick is to hold the unit completely level so it will come out. Now for the hard part, keeping it level, keep turning it past the end so you can get a very small screwdriver in the side of the end. There is a fat white pin that holds the seatbelt in the center peice. push the seatbelt though or pry the end out. take out the plastic pin and pull the seatbelt back out. The pin keeps the seatbelt from falling out of the holder. MAKE SURE TO HOLD ON TO THE PART THAT SPINNS AT ALL TIMES!!!! If let go, it will take a very very long time to reravel the spring inside. Once the seatbelt has been completely removed from the unit, tighten the spring by turning the center 4-5 turns more(note you coundn't do this with the seatbelt still in there). Once you have it as tight as you feel confortable, push the seatbelt back though the center, replace the pin and seat it back in there. Let the spring take up all the slack and walla!!! Your seatbelt works again.

I may sound a bit complicated but it took me 15mins to figure out and do. Just don't let go of the center with the belt removed!!!!!!

Josh

Josh performed this on an '86 Toy truck, it may involve more work on a T100 though.If anyone is willing to try it and see if it will fix the problem with seatbelts, let's let everyone with a T100 know. Sorry for the long post.