Rumbling Heater/Blower Motor???

[bernieeccles]

Recently, the blower motor on my IS250 started to make a horrible rumbling sound which was more prominent at higher settings but gradually got worse. A new motor from Lexus is pushing £500 and one from a breaker about £70 to £100. Of course a used one might end up the same depending on mileage. A quick look on Youtube found the following video on removing and dismantling the fan. I took his advice and bought a couple of small ball bearings and fitted them but they didn't work and were very noisey.

I removed the 2 bronze bushes and measured them and the shaft from the fan. The shaft was approx 8mm and the bushes had an inside diameter slightly bigger but had worn badly causing the fan to rock. The outside diameter of the bushed was 14mm and about 14.5mm long.

A search resulted in finding a supplier of new oilite self lubricating bushes but imperial. 5/16 x 9/16 x 3/4 which are very close. So having bought two of these and some new Starlock washers, I basically started an 8mm drill through the center to slightly enlarge the hole and kept trying them for a fit over the shaft until it was a smooth fit. Next I had to reduce the outside diameter a fraction so I could press them into the plastic carrier in the coil windings.

Assembled everything with a new Starlock washer and the fan is now whisper quiet. All done for just over £10. One other thing is that the guy in the video describes the circular disc under the locking washer as a thrust washer. It is actually magnetic and I think has a part to play in the electronics so don't break it. I also took out the top washer of three at the bottom of the shaft and put a copper washer so the flanged bush would bear and run on that.

Taking the fan out and pulling apart can be done in minutes. Links to video and suppliers below. The whole process is much easier than reading the above would have you believe.

https://www.hendersonbearings.co.uk/catalog/product/view/id/74546

https://www.ebay.co.uk/itm/163259494535

 

[Texas]

Well done that man, excellent info.

[Stevie1529]

Thanks for this, parts ordered. 

[Herbie]

Love it when a good DIY job comes to fruition, well done mate.

[bernieeccles]

Just an update.

Blower motor still working quietly and I should add that when assembling the motor spindle into the new bearings, I added a bit of Moly grease even though these are "oilite" bushes.