MemberNovember 11, 2016 at 12:00 am
Trying to replace the bottom fan motor and cannot get the blower wheel off of the fan shaft.
MemberNovember 11, 2016 at 11:37 am
To further assist you, it would be helpful to get the model number of the Rational unit you have. We might find diagrams or one of the techs who frequent the forum may have worked on the same model you have.
MemberNovember 11, 2016 at 12:02 pm
Basically you loosen the set screws and either use a puller or get behind the hub with 2 suitable pry tools. Penetrate also helps.and cleaning any exposed shaft prior to removal. Do not pry on the outer part of the wheel, only the hub. Some wheels are tapped to install a puller. In that case clean the threaded holes out with a tap, find suitable long bolts and use a crossbar puller or a bar with holes to jack it out. Recommend a high temp never-sieze on the reinstall.
MemberNovember 11, 2016 at 3:29 pm
They’re definitely not your usual blower wheel, that’s for sure. The motor shaft is conical and obviously the wheel hub is shaped to accept it. The wheel is retained to the motor by a single bolt in the center of the motor shaft.
I’ve had to removed those blower wheels often. The tools I use are:
- Metric socket wrench with extension (of course)
- A propane torch
- A large, long screwdriver or pry bar (for the puller)
- A large adjustable wrench (for the puller)
- A larger puller that looks like this:
You’ll also need a new motor shaft seal. OH…and SPARE wheel retaining bolt, since you might bend the one it has while trying to remove the wheel. I use a Allen head bolt of the same size, remove the factory bolt and screw the Allen head into the shaft. The Allen head is easier to center the puller on and, if I bend it, I just toss it. However, I still recommend having a new OEM bolt, since it’s best practice to replace the bolt instead of re-using the old one.
Here’s how I go about removing the blower wheel:
- Loosen the hub retaining bolt and turn it out just a few turns. That bolt will be the landing for your puller.
- Install the puller, center it on the bolt head and tighten the puller down enough to where it’s got some pulling tension loaded up.
- For leverage as you’re tightening the puller, use a large screwdriver or a small pry bar. Wedge that between any two legs of the puller, then tighten it further. Very likely it will begin feeling really hard to turn. Stop there.
- Fire up the propane torch. Direct the flame at the hub collar (NOT at the bolt and not the thinner metal that forms the blower hub). Use a wrench handle, screwdriver or other tool to rotate the blower wheel so the hub collar is being heated evenly around its permeter.
- The last step is to JUMP when it scares the @#%& out of you as the wheel ABRUPTLY comes loose. The bolt contains it, so the wheel and your puller will like stay put.
Whatever you’re up to there (replacing motor maybe?), be sure to replace that shaft seal.
FWIW, Rational does sell a puller set for removing their blower wheels. They’re PRETTY PRICEY (@ almost $700) and looks like this:
If you follow my steps, you won’t need that…and that wheel will LITERALLY jump loose from the motor shaft.
MemberNovember 12, 2016 at 9:43 pm
I particularly enjoy the ones you pretty much stand horizontal on the unit to pull of and it suddenly pulls off and you do the damnedest dive anybody ever saw.
MemberNovember 17, 2016 at 2:19 pm
I like when you go to the tool room for the puller set on a tapered shaft wheel and the give you a slugging block and a BAH.
MemberJanuary 20, 2018 at 2:30 am
I removed 2 motors and did it the same way . You just have to make sure you have a good grip on the wheel tighten it up ,apply heat and POP! it’s off .
MemberJanuary 26, 2018 at 1:07 pm
I’ve used ecto’s puller. with great success it s quick and easy. I also used a smallish bearing puller. Its two halves that go around the shoulder, on the end of the fan. A third piece clamps down and pulls the two halves. The new motor should also come with a new bolt. I loosen the bolt up a few threads but leave it on so the thing doesn’t fall off on my foot.
One last thing that I would recommend would be some ear plugs. Besides scare ing the hell out of you when it does let go, the oven cavity will give you a real ringing in your ears.lol
Log in to reply.