rusty, There are several different type of rollers that have been used on sectional ohverhead doors. Some are steel shafts with a nylon roller. These have no bearings in them. They rely on the nylon to act as a bearing. These are very cheap rollers with a short life. The low end steel rollers are designed for lightweight residential-duty doors. They have seven ball bearings in them but the balls don't ride on hardened surfaces. They last about six years and then start falling apart. The commercial grade of 2" roller have more balls that are in hardened races. These last four or five times longer than the seven ball type. Anything will ball bearings needs lubrication. We used 10W30 or even ATF. Any light viscosity oil is fine. Rollers that do not roll with develop flat spots on them and then never roll no matter what you do to them. If your door won't stay in the full open position, then it needs a spring adjustment carried out by a Pro who knows how to adjust springs safely and to make adjustments to the cable lengths so as to take advantage of the Hi-lift portion on the cable drums. Trust me. There's a lot more to a properly adjusted door than what most people realize or even know. I have come across all kinds of botched jobs by guys who shouldn't be allowed anywhere near a door. I used to put electric operators on doors like you have that lack headroom above the door. There are ways to make it happen if you are on top of your game.

Of course Don can speak for himself, but I know that I would not just replace the drive unit on an old machiine. It's akin to replacing the motor in an old tired car without considering the suspension/wiring/etc. You will get most trouble-free longevity starting all new again. Especially, when you bought the complete setup anyway. FWIW, when I replaced my craftsman opener the header bracket for the rail changed from the old style but the new unit contained an adpater to connect the new rail to. So it was really just swapping out the whole machine. Of course you have to add the sensors and hang a new wall button, too. Seems foolish, but as long as you're satisfied, good luck with it.

'96 Craftsman 139 53648SRT model 1) problems closing....go down a lil a come back up. RPM sensor I suspect ??? 2) LED flashing 5 times.....RPM sensor ? 3) while researching above problems...now when the remote or wall unit (no pad) is engaged, there is nothing but a slight/quick "humming" noise..and nothing happens. This is a new symptom. 4) I have checked/tired to align the infra red sensors.... this model has both lights on constant, regardless of whether they are in sync or not. I checked the wiring from teh sensors back to the motor/unit. I'm not sure how to align them now. QUESTIONS: which do I address first ? I'm not sure I can align the infra red sensors without the "humming" and no activity when I engage the opener. Should I look at the RPM sensor first ? Is the gear stripped ??? causing the humming and non activity ? The opener was opening before I started working on it. Thanks to anyone and everyone who has advice on this.

Thanks, one more learning on modern door openers. The door system I have has a separate (not part of the motor housing) radio receiver that has switches to change the code (manually), it requires its own access to power and when it gets an open/close signal closes a circuit to the motor/controller. I guess it must have at least three wires common, up, down. The new units are silent on any such outside unit they just show the motor assembly, two remotes, a key pad controller, and another controller - plus the beam safety stop. Thus I guess the radio receiver is in the motor assembly. I noted too that my existing unit is only 1/3 HP, I have two doors on a two car garage. So the 1/2 HP is plenty of power. Stopping by Home Depot before going to the nearby Sears catalog store I found the subject Genie Chainmax 3/4 HP still on sale for $119.99 down from $179 but next to it is a sales priced 1/2 HP Chamberlain at $109.00, down fro $166.00. It too has two remotes, an outside key pad and a hand unit that can be used to control the door, lights, and even disable the wireless as an extra security feature. I have always turned the power off the the garage doors when on vacation - and use the manual door locks too. Given Craftsman/Chamberlain seem to be the same horse with different name plates I purchased the Chamberlain. I haven't yet opened the box and likely will not for a few days, so I'd appreciate any information you have on where the radio receiver is located on newer opener systems... as I typed it appears to me the receiver must be included in the motor housing - that would save some wire running making the installation easier. Sorry for dragging you along, but I assume others are reading along and gaining useful information therefrom,