Trouble with garage door opener

[Turaj]

So, in the middle of a busy week (and just before a business trip) our garage door opener (Chamberlain?) has stopped working. I have checked a few thing already:

The remote works, there is power to the unit, the motor sounds as it works but the pulley (where it engages the chain) does not rotate! The door itself moves fine manually.

Anybody has had this problem before? Is there something that I can check or should I just change the unit as I don't know much about electric motors.

Any help or pointer is greatly appreciated

[capncarl]

I have replaced a motor and a control board at different times on my door operator and found that it is not much cheaper than replacing the whole drive. The last episode when the control board died I considered replacing the whole drive unit as it was only $40 difference but decided it was too hot in the garage and I could replace the board quicker.

[Lonnie in Orlando]

I too have replaced the sproket hardware and circuit boards on my two LiftMaster (Chamberlin) openers at various times. They are about twenty years old.

I had problems with both of my openers in 2010. It was faster to replace the parts than to install new door openers. Everything worked when I was finished.

I purchased the parts from ...
http://www.northshorecommercialdoor.com/

Here's what I bought and paid in Nov 2010 ...

(1) $21.00 #41A4373A Liftmaster 41A4373A Safety Beam Kit

(1) $25.00 #41C4220A Liftmaster 41C4220A Gear and Sprocket Assembly

(1) $65.00 #-41A4252-7G- LiftMaster Chamberlain 41A4252-7G Garage Door Opener Circuit Board

Subtotal $111.00
Shipping $6.95
Tax $0.00
Total $117.95

- Lonnie

[Zip1]

Strongly suspect the worm gear and sprocket.
Take the sheet metal cover off and see if you find plastic shavings inside.

Very common replacement parts and often universal between Craftsman and Chamberlain.

[LCHIEN]

If the motor runs but the chain deosn't then the problem is likely the same common one as I had. You don't say how old it is but I'll bet 10-17 years.

On a craftsman garage opener, Stupid thing has a pastic gears between the motor and the chain sprocket. See this thread: http://www.bt3central.com/showthread...ge+door+opener
When I took the bottom cover off the GDO, it had a pile of white dust and debris in it. Gear remnants.

Chamberlain and Sears Craftsman GDOs made by the same people, I guess Chamberlain makes them for sears.

[Turaj]

Many Many thanks guys. I'll open it up in the morning and check to see if I have the same problem. It definitely sounds easier to replace parts and I know where to ask more questions if I need too

Loring, you are absolutely right about the age, as I installed it back in 1997. Thanks again and I'll let you know how it goes!

[mpc]

Add me to the list of folks with "white gear snow" in a Craftsman GDO. I have a Sears parts store close to me and they had the repair kit on the shelves out front - didn't have to order it. It's a very common repair kit. Not too difficult to install either. It came with a squeeze packet of grease. No mention of needing to periodically grease the GDO internals in the original owners manual either (just the trolley & track)... maybe that would have made the white plastic gears live longer? 20-20 hindsight.

When you open the unit you'll probably see skinny electrical switch contacts that are opened/closed by the mechanism; these switches are adjusted with the up/down travel adjustment controls you tuned/adjusted (probably with a screwdriver) when installing the GDO. Be careful around them, they bend easily. I'd take a digital pic of the guts prior to taking stuff apart to get to the gears just as a backup. And don't forget to unplug it before opening it!

mpc

[LCHIEN]

all kinds of on-line tutorials on replacing the gears as this is a common problem. Just google I imagine, "fix garage door opener gears craftsman sears chamberlain" all or part of that.

[cabinetman]

I have replaced a motor and a control board at different times on my door operator and found that it is not much cheaper than replacing the whole drive. The last episode when the control board died I considered replacing the whole drive unit as it was only $40 difference but decided it was too hot in the garage and I could replace the board quicker.

I would replace what needed replacing especially if the gears were upgraded to a better material than plastic.

.

[Turaj]

GDO - Update

So today I had a chance to open the GDO and the problem was exactly as described by everyone here, the plastic gear had worn out and there was white plastic powder inside the unit.

I inspected all the parts and clearly the gear is the only damaged part (the shaft assembly and worm gears are all fine). It seems to me that I can just change the gear without taking the motor out (the same way that I took the gear out). This would save me some time and hastle but was wondering if anybody sees any problem with that.

Once again thanks for all the help

[LCHIEN]

I'd just replace the gear. They sell kits with parts ranging from the gear to all the drive train parts but i think those are just to separate you from your money.

[Lonnie in Orlando]

The "Gear and Sprocket Assembly" ($25.00) that I bought to repair my opener had good instructions. I don't remember how much of the opener I took down. It was a pretty straight forward repair with the instructions.

- Lonnie

[LCHIEN]

Here, I hope you find this useful. Also an alternative to buying gears from sears; they list all the kits available.

http://www.stardoorparts.com/How-to-...gears-s/30.htm

main gear and lube: $15 http://www.stardoorparts.com/Liftmas...41a2817-cr.htm

note what they say: You MUST apply a low temperature lithium grease (included) to each tooth of the new gear or it will shred within days.

[cabinetman]

Seems like using plastic gears falls into the "planned obsolescence" category.

.

[LCHIEN]

Seems like using plastic gears falls into the "planned obsolescence" category.

.

That might be. Or you may be being uneccessarily harsh to the designers and marketers.

It might be a planned engineering decision to make the gear the weakest point (e.g. a mechanical fuse) so that a jam and a failed force limiter won't pull down the garage structure or break the door.
I can't really say for sure. Maybe its a little of both.