When the blower is turned on, using either heat or AC, the whole house vibrates.

Technicians diagnosis revealed that the blower was not balanced properly, which was my initial guess. Inspection also revealed that the fan (squirrel cage) had begun to rotate around the axle of the motor, despite the locking screw which was supposed to align the fan with the flat part of the axle. ARS Service Express wants $400 to replace the blower wheel, which I would assume means the squirrel cage.

I'm mechanically inclinced and don't have a problem doing the work myslef, if I could find out a few details. First, how do you remove the wheel/squirrel cage from the axle of the motor? Second, how do I find a replacement?

The furnace is Trane BTB 724 A100A3

Thanks for the help.

Patrick.

caibuadday

if the wheel still in good shape you may able to balance it your self ( by trail and error). use the balance clip or self locking screw....... to remove squirrel case open the cover (round) on the side of the fan housing..... go to a AC store, some suppliers sell part to contractor
only

letmetellu

If the set screw is still in place( that is tightened against the flat spot on the motor shaft) and you can turn the blower wheel that means that the blower wheel has come loose from the hub. These are crimped together and once they start to rotate there is nothing you can do but replace the blower wheel.
To replace the wheel you will need to dismount the motor, start by using a emery cloth on the exposed portion of the motor shaft, this is to make the hub slip off of the shart easier. Loosen the set screw, remove the three bolts that is holding the motor mount to the case. Using an adjustable wrench (Cresent) adjust it to fit the flat part of the motor shaft, Turn the shaft as you hold the blower wheel, in this case the wheel may turn without turning the hub so you may have to find a way to hold the hub as you turn the wheel. This should let the motor move out the open end of the blower housing, this could be a real problem and take lots of WD 40 if the shaft is rusted. Once the motor is out of the housing you have to take a plate out that controls the flow of air coming our of the blower housing. Make sure you mark the exact holes that the screws are in before you remove them. You will see this plate because it is where the air exits the gage, which would be the top of the blower if it were still in the furnace. Next note which way the fins are turned and remember how it comes out of the blower.
Go buy a new wheel and reverse the procedure. before you tighten the set screw on to the flat part of the shaft make sure that the blower is equal distance from the sides of the housing and that it will turn freely.
If you can not find a wheel exactly like the one you have it will be ok if you buy one that is a 1/2 inch narrower and if it has to be 1/2 inch smaller diamiter.

pharr080

Thanks for the help!

To explain further, the set screw is no longer aligned with the flat part of the motor shaft. The hub along with the wheel have rotated about 30 degrees past the flat part of the shaft. The hub and wheel are still solidly together.

My concern is that the motor shaft and hub/wheel combo have become stuck together. I'll try rebalancing the wheel first as described by "caibuadeday", because that doesn't require taking the assembly appart.

But if I can't get it balanced, would anyone have any other suggestion as to removing a wheel that has become stuck to the motor shaft?

Thanks!

Patrick