Doubled33

I have been a lurker for about a month and the Stork Delivered a Midnight Blue 91 964 Tiptronic Cab on 7/21/12. In looking at this car I knew the front blower motor was bad, and I was determined to pull the motor and repair it rather than replace it with a pricy motor. I also wanted to give something back to this form for all the good info I have read on other subjects. The following details the motor disassembly and bearing replacement after removal from the car. There are plenty of good posts on removing the motor from the car. I only replaced one of the 2 bearings but when you get it out the second bearing will be just as easy if you want to replace it. This is not for the faint of heart and requires some skill, a dremel, and a TIG welder, and a 8x16x5 mm bearing. I do not have access to a metal lathe/milling machine anymore otherwise I would have made a few improvements. I spent all of $3 on this motor fix, and that was for the new bearing.

The following pics describe the process. I Installed this motor in the car and I have no funny noises or vibrations, but your results may vary. If I had access to a lathe or milling machine I would have made a different holder for the new bearing and bolted it to the motor in lieu of the spring tab. I would have also made a better puller for the spline on the shaft. The bearing I purchased was readily available on an Auction Site and possibly available at a RC shop as it seems to be a popular size. The thickness is important as it fits snug in the spring clip but not too loose or tight. The shaft size on mine was 8mm hence the ID of the ball bearing. When looking at bearings you want a sealed bearing. Good Luck and I hope this helps someone not buy an expensive motor!

ToreB

Impressive! And very good information to others.
Cheers,
Tore

alexjc4

That's great stuff, well done!

It looks like the spline drive was probably heated and then cooled/shrunk on to the drive shaft in manufacturing?

I wonder if you could use solder/sodder in the place of TIG welding when you're putting it back to together - after all its not got to stand up to much loading?

Doubled33

The splined shaft was probably heated and shrunk from the factory as it was very tight. I used a little heat, but it still would not budge.

You could probably use solder or braze on the splined piece. I do not know that solder would work on the motor housing. Perhaps you could use a chisel to crimp these down again similar to the way they were before the tabs were ground off.

tbennett017

How about JB Weld? The universal repair tool of mullet-mechanics?

alexjc4

For the spline shaft you could use something less permanent like red/strong locktite or drill it and stake it with a roll pin, that way you can replace the bearing when it wears out . . . Who knows how much a replacement fan will cost in 2032.

Doubled33

JB Weld and Locktite would probably work as you just have to stop the splines from spinning on the shaft and fill in the metal. Obviously a TIG seems to work the best, but I understand not everyone has one of these in their garage. I had the Roll Pin thought, but the shaft is somewhat hardened on the outside and it would take some time to drill. If I have to replace again, I would probably have to cut out the weld.

Makmov

the spline sleeve was probably frozen then pressed on the shaft.

jgrosjean

Nice job! I will remember this when mine fails.

Romanoaf

Resurrecting an old post just to say that I finished this today without welding, obviously to Dremel and weld makes for an easier job and might be a little cleaner but if you don't have it available to you; it is possible to do.

What I did was:
Pulled the squirrel cage off with a 3 jaw puller
Used a chisel and hammer to bend back the crimps on the holder (try your best not to bend the holder, or you'll have to make sure it's centered when putting it back)
Unclip the spring clip and let it hang, remove the holder while the bearing remains on the shaft.
For me, the bearing wore on the outside against the holder, so it was still snug against the shaft- I could grip the bearing with the puller to pull the collar off with out cutting

To fit,
Put the holder back in place (with bearing and spring clip assembled) now you can either re-use the crimps via chisel and hammer or use some adhesive/epoxy (I did both)
Make sure you put the plastic pieces on before re-assembling the cage (I forgot to do this and had to take it apart again)
Then be sure to fit the collar to the cage BEFORE putting it back on the shaft- I used a mallet to force it back in- once in I put the old bearing over top of the cage and hammered that to get it in the extra 1/4" or so.

I just finished this tonight, seems to work perfectly so far.. Will report any issues if they arise.

cobias1

tried this today then as I was welding it back up...the stupid bearing retainer broke both flimsy tabs...anyone know where to get one of those??

ziu

Good idea, should fix the rear blower bearing problem as well.

alexjc4

I though I come back to this having swapped the motor on my front right blower recently.

To extract the plastic squirrel cage I cut the back and front bearing holding plates off the old motor, back access is easy, just hack saw, front is tricky but in a drill press you can drill a chain of holes carefully between the spokes of the squirrel cage once thats done you can pull all the motor components off the shaft leaving just the shaft with the squirrel cage and splined sleeve still in place.

That allows you to press the cage off the spline using a suitable size socket, and then finally puch the shaft out of the spline sleeve by supporting the shoulder of the sleeve in the vice and using a punch from above.

Pressing the cage back onto the sleeve and then both back onto the new motor shaft was easy enough using a vice and a few sockets and a little plusgas for lube.