We have a Sears garage door opener and the door goes down to about
10-12 inches from closing and bounces back up, we have to push down on the door to get it to close.
We have tried lubricating the rails and chains and the sensors are fine. Lube works in warmer weather but does nothing when its cold. It has been getting progressively worst every year with this winter it not closing no matter how many re-tries.
When I release the door from the opener and walk it down, it seems to hang up when the top wheels in the track reach the beginning of the radius. When using the opener you can see the opener track bow up when the door reaches that point and then the door reverses.
The side wheels on the top panel are aprox. 18" apart while any other two are 21" apart. I moved the top bracket/bearing about an inch up but can't get it any closer to the top of the top panel because of a aluminum stiffener or whatever across the top of the door that sticks out about 2 1/2" by 1/2" thick. Any suggestions?

There's probably nothing wrong with garage door opener, it's designed to reverse any time it senses resistance. Based on your description, it sounds like there's some misalignment where the straight rail joins the radius.

Do the wheels on both sides bind, or is just one side?

I think DR is on the right track. If this used to work and now is getting worse there is a misaligned track somewhere. Inspect all the connecting points and I think you'll find one that shows it has moved/slipped. I think it is more likely a wheel bracket on the door itself rather than the track. That's why the first few sets of roller can make it and not the last one, its onlt the last one that's out of line.

I thought it was the radius and the shorter wheel span on the top panel, but after your posts I checked the wheels with the door in the closed position and found that the second wheel down on one side was not a little free like the other ones but was jamming the door against the wood frame. I shimed out the top two rail brackets about an 1/8th (a paint stir stick) away from the wood and the door works fine. I don't know if this will be a permanent fix, or if my door frame is shifting with the seasons, but thank you Dr and ballenger for your posts to make me take a new look at the door.

Glad we helped you out.