QUOTE(Joe Owensby @ Aug 26 2010, 06:10 PM)

Do not release the springs from beneath the cover. The springs can be rewound fairly simply. Pull the entire length of the belt from the reel. Then, with a dull screw driver, push the loop on the belt back through the slot in the center of the reel, while holding the reel to keep it from turning. I used a pair of vise grips to lightly grip the reel to keep it from turning. When the belt is pushed back in, you can see a pin that goes through the loop in the belt. Remove the pin, and then pull the belt out. You can then use two screw drivers to incrementally either unwind or rewind the spool. When you get it to the point you want it, just re-install the belt through the slot, insert the pin, and pull the belt so that the pin goes back into the groove in the slot. This can all be done without removing the cover on the spring. There is a thread somewhere showing this. JoeO
This works OK but the problem is that the belts typically need to be tightened much more than this method can deliver. You can only wind the spring up until it binds and then insert the pin/belt
I leave numerous wraps on the belt around the spool, then pull the cover off (DANGER!!)and wind the spring even further. This method loses some belt length but unless you are a size 44 waist, you'll never even know. The advantage is that you get a firm retracting belt that works the way it's supposed to.
90% of the belts I have seen won't retract properly without leaving some wraps around the spool and then fully tightening the spring.
Also, I wouldn't use any oil on the mechanism. It will attract dirt and could cost you your life. A good cleaning and a wee bit of graphite works well
YMMV.....