1985 IROC

Is it possible to rebuild the driver's seat belt retractor that's mounted on the roof? Mine is spun out. I tried to fix it by moving that lever which sits in the slot on the pinion, but that didn't work. When I looked at the other side, I noticed that the blue spring cover was off. I am assuming that the spring has come unsprung as well. I haven't been able to find a guide for doing this.

As far as the gauge cluster goes, my fuel gauge isn't working. I haven't checked the sending unit in the back yet, that's what I hope to do today. If the sending unit is good, and the wiring is good, is it possible to only replace the fuel gauge on the cluster?

The reason I ask (and a slight concern) is that the car receiving the cluster has the RPO codes E5Z (speedometer adapter delete), E9Z (speedometer key delete), and E7Z (not found in the RPO decoder, so I don't know if this one is important to this situation or not). I would want to put in a 145 mph cluster. Would the 145 cluster show the correct speed if the car it was pulled from didn't have the delete codes?

I would much rather replace the gauge than the entire cluster. This car has just over 39k on it, and is in very good shape (barn find). I would much rather bring the car back to original condition if possible, also the reason for asking about rebuilding the retractor unit.