Heater blower motor rebuildable?

[Wanaja73]

My heater blower is making a terrible noise, and I'm thinking of rebuilding it with new bushings/bearings. Machining is no issue here. The only question is, can you tear it apart? It seems the fan is really stuck, and I cannot see if the thing will come into 2 parts when the fan is removed?

I think $135 for the motor and another $70 for shipping to Finland+customs and taxes is way too much for such a thing. So if I can fix it, I'll do it. But if I can't, I guess I just have to swallow my pride and dig out my wallet....

[Dakota Boy]

Perhaps it is similar to opening up a power window motor? There is a section about opening up those motors and rebuilding/restoring them in the TRL.

[partsetal]

I've never been able to get the fan off of the shaft without damaging the fan. If anyone knows of a solution, please let us know. The motor is like any other 12v motor and if you have the parts you can rebuild it.
Carl

[simplyconnected]

I pulled mine apart and cleaned/oiled it. Mine came from my '55 and is six volts but otherwise identical. When you take the set screw out of the fan, make sure you file the motor shaft smooth so the end bell can slide off easily.

You have another option... More modern 12 volt motors have just two wires (ground and power) and they are less expensive. Simply use a resistor in series with the LOW speed wire and run the HIGH speed wire directly.

The Key Switch feeds to the Heater Switch, then two wires go to the motor. Your original motor has two field windings for speed control, that's why you have two wires coming from the Heater Switch. Adding a resistor is very easy to do and most auto parts stores carry heater motor resistors at reasonable prices. - Dave

[Joe Johnston]

You may get lucky and just apply a drop of oil on the exposed shaft on the blower end. The closed end of the motor can be drilled on center and a bit of oil inserted via a pin oiler or something similar. 2 drops on each end will be plenty, so don't over do it. Not only rotate the shaft, but push and pull it to make it slide back and forth to help the oil work in. If the motor frees up, close the drilled hole with some type of sealer or caulk to keep the dirt out. I have been able to fix some like this and it is worth a try instead of taking everything apart.

[Wanaja73]

Thank you all for the answers. Joe, the problem is, that the shaft is loose, so there's definitely something wrong with the bushings.

Simplyconnected, yes, it would be easy to throw modern motor in. I've found some motors will fit. But that would be too easy I'd really like to keep the old motor, because the whole car is unmolested and original (at this point, though )

Ok, maybe I'll have to fabricate somekind of puller for the job.

[Joe Johnston]

If its that loose, new bushings are probably in order.

I've never been able to get the fan off of the shaft without damaging the fan. If anyone knows of a solution, please let us know.

Remove the set screw.

Its not easy but hold the fan and a small punch or a bolt upright that will go through the fan hub and rest on the motor shaft. Hit the punch with a hammer. Go pick it up from wherever it flew and do repeatedly until you drive the shaft out of the fan. Clamping the fan or holding it on something solid is likely to bend it when force is applied, but having it loose in your hand seems to be the key to let the impact hit only the end of the shaft.

[partsetal]

Joe,
I'll try that on the next one. I've always tried to support the area around the hub of the fan, plenty of penetrating oil and a punch. If that doesn't work, I'll send it to Dave.
Carl

[simplyconnected]

...If that doesn't work, I'll send it to Dave...

2112 N. Vermont Ave.
Royal Oak, MI 48073-4204

Send it now, while the weather is nasty. In good weather, I will be outside. - Dave

[simplyconnected]

Heater Motor Refurbishing

One day last week I found a box on my porch from Carl Heller. I ordered no parts so I was surprised to see such a large box. Then it dawned on me that I invited him to send his heater motor that he was having troubles disassembling.

I laughed out loud while opening the box. Inside was the fan and motor assembly with an envelope with his calling card and CASH! I love cash, and this was $24.

This day was our first 60-degree day this year so the challenge was on. Carl had loosened the set screw but nothing moved. The squirrel cage was frozen to the motor shaft and the motor would not budge; a job for PB Blaster!

I noticed that the set screw was not aligned with the flat part of the motor shaft, which is odd. After hours of 'soaking' in 'Blaster and finessing, the fan finally moved. First a little, then back and forth a few hundred times then it 'screwed' off.

The threads on this set screw are 1/4"-28 which is rarely used today but I have a tap. I put the set screw back in the fan hub and noticed that it tightened hard just as the point came through the center hole. Not good. The set screw needs to keep going so it can tighten on the motor shaft's FLAT part. Then I noticed the witness marks on the motor shaft left by the set screw. It was on the round part which made disassembly difficult. Forget pulling the armature through a bearing sleeve with raised upsets. I tapped the hole through so I could use the flat part of the motor shaft.

Next, the end bells wouldn't budge because the brass bearings were frozen solid. Each end bell has a riveted bearing keeper with felt to hold oil. I ground off the rivets on both bells. This allowed the bearings to remain on the armature shaft while I removed the end bells.

There was so much rust I didn't believe restoration was possible without damaging internal parts. The other components looked decent. I took all the steel parts and acid dipped them while I cleaned the carbon brushes, micarta brush holders and spring, and I simply wiped the commutator segments off with a dry rag. They look like new and so do the brushes.

Brass bearings do not rust but the steel inside did. Again, more PB Blaster and more finesse using Channel locks and Vise Grips. Finally, one came loose then the other. I put the armature in my drill motor and polished the bearing surfaces with very fine sand paper.

Time to re-rivet the bearings back into the end bells but first, a little etching primer paint and black Rustoleum in a rattle can. I found some fleece material to replace the nasty original felt and I used 1/8" stainless pop rivets to secure the bearings.

I made a detailed full-screen video that is rather large so give the buffer time to load... CLICK HERE
Questions???
Oh, the actual motor is much quieter than the video for a few reasons. One is, I was sitting next to a running furnace.
Gracie (German Shorthaired Pointer) is not that shy but she didn't like the air blowing off the running fan. That's why she looked at me and was reluctant to get her ball under the fan.

These fan motors are built like tanks and they should last forever. This one is a single speed fan but it can be multi-speed using resistors. Carl Heller has his fan back. I hope he powered it up to check it out. - Dave

[toddgilroy]

Dave you obviously have more finesse (and patience) than I do.

I tried PB Blaster, heat, finesse, force, etc...but could not get it to budge. The fan was badly rusted and not round, so it was going to be replaced anyway. I used my Dremel and a tie rod puller.

[simplyconnected]

With all due respect and I don't mean to contradict you but using a tie rod puller (a pickle fork) is not using finesse.

BTW, I would repair this fan by making a simple donut out of sheet metal and either spot or MIG weld the two parts together.

Carl said he used heat on the fan before I got it (with no luck). I don't like using heat unless it's 'do or die'. I will do anything to preserve the motor's internals.

If it helps you guys, I will gladly separate your fan for you. Simply box it up and send it to me. - Dave

[toddgilroy]

No worries Dave, I gave up on the finesse once I plugged in the Dremel.

But I didn't go as far as s pickle fork. I used one of these.

[simplyconnected]

Todd, you're teaching me something I never thought of. I call that tool a pitman arm remover but I never tried it on a tie rod end. It certainly would do the job... But for tie rods, I loosen the nut then smack the sides of the receiving end using two hammers. The taper flies right out. Funny how we become accustomed to our own methods. - Dave

[Tbird1044]

You have inspired me to take my spare blower motor assy. apart and clean it up, while I wait for the return of my car. It was a great video. I'm very impressed.
Nyles