prescott

Time to start planning my timing belt/water pump job. My cooling fans are beginning to sound "crusty" and loud when they turn on, or when the AC cycles. Is there a write up for lubing these or fan motor replacement for these while my " local indie" does the job?

Thanks In Advance!
Brian

Ducman82

you can replace the blade/motor set up with a nice factory unit. Spendy, but it will last 30 more years. i have not seen any aftermarket motor units.

Kevin in Atlanta

I was considering refurbishment, but the Bosch fans can be had for 150 a piece new. That's where I'm leaning. I believe it was DR that pointed out as they age they cause additional resistance that can lead to melted fuse panel sockets. Since mine have signs of melting new fans seems like cheap insurance. YMMV

Ducman82

that is correct. i have replaced quite a few melted fuse blocks. not only do the fuses corrode , but the increased demands of the dying brushes in the fans can cause the heat and melting

merchauser

I bought a new pair a few months back from roger, and could not be more pleased! so much more quiet and
even better, reliable. I would definitely recommend, and truly, worth the price. nothing worse than having fans
that either don't work, or work intermittently!

ROG100

I have plenty in stock - original Bosch for $150 each.

merchauser

that is a steal! peace of mind for sure. I wouldn't bother with ebay sites, when roger
sells exactly what you need and stands behind it!

dr bob

FWIW, worn brushes add electrical resistance and therefore reduce the current flowing through the fan and the fuses. Don't blame worn brushes for melted fuseholders. Blame the fuse contact dirt & corrosion that increase electrical resistance there too.

Major blame goes to plain old bearing wear in the fan motors. Worn bearings add vibration and also mechanical resistance. Noise and higher current draw, respectively, are the direct results of that wear. The new ones give you nice clean electrical connections, with new bearings and brushes, motor windings not shaken loose or even apart by the failing motors.

Roger, I'm working on my next-winter projects list.. I'll take a couple of those fan motors in the box then please.

928Myles

The fan bearings are a common and inexpensive bearing.

There is an extensive write-up on the forum that shows how to replace them. Not particularly hard.

https://rennlist.com/forums/928-foru...iator-fan.html

V2Rocket

new motors?
your website doesn't show anything titled "fan".

thanks to this excellent writeup you can recondition your fan motor in a matter of hours.
bearings are about $1-2 and some electric motor lube for the rear bushing/felt pad.

ROG100

Spencer - With so many new 928 parts I gave up on a web site years ago.
All my customers Worldwide deal with me directly by phone or email.

All - Thanks for all the orders.

merchauser

its not just the bearings; you have 30 year old fans, that have been exposed to years of use and abuse, compromising
the plastic, and the connectors, which get brittle, and break.
for me, it was a no brainer to get the new fans from roger. your cooling system id too important, in less than an hour I had
them installed and the whole cooling issue was put to bed for another 30 years. I wouldn't mess around with rebuilding anything.
in the end, it could cost you more cash and more headaches

dr bob

I'm of the same thinking. I'll get the fan motors from Roger, install them with the winter 2019-20 timing belt project. The old fan motors will be carefully disassembled, cleaned, new bearings and brushes, and stored away with all the other rebuilt original pieces that arrived on the car when it found me.

The bearings are fairly common if you look for rollerblade bearings, but the versions we want aill be double-sealed and at least single-shielded. The skate wheels tend not to have the metal shielding that keeps debris out. There are various grades of bearings too, with some a little more "precision" than others. Lesser grades offer potential for more later-in-life vibration. Vibration is a winding-killer in electric motors, along with heat and contamination.

Well-used motors will also suffer from commutator wear, and that's something the DIY "rebuilder" isn't able to restore. The brushes ride on a series of copper commutator pads, each pad connected to a section of the armature windings. The rotating armature then sees its magnetic field stay relatively stationary between the magnets in the case, so that the fields are always out of phase. This is what causes the armature to rotate, as the armature fields try to align with the stationary magnets. The bushes wear away at the copper pads, and the mica insulators between the pads wear down with the copper. You can sometimes "dress" a mildly worn commutator with sandpaper (NEVER with conductive aluminum-oxide strip abrasives) to even out the surface. But that effort really just wears down the unworn sections to match the worn sections, so it's not really a rebuild when you do it that way.

Sagres74

If I recall correctly, Hans has a whole fan assembly that is slimmer, lighter, with newer fans that draw less amps but pushes more air. Just another option.

https://rennlist.com/forums/928-foru...an-shroud.html

SeanR

I'll let Hans comment on that, but one car I have them installed on has had both fans fail with in a couple years. I heard he's going with a different supplier.