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Over the past several months I have noticed a "ding ding" noise that was apparently caused by the cooling fan slightly touching the shroud due to a very slight wobble. After speaking with several mechanics it was decided to purchase a new fan (Not Cheap)which already has the Fan Hub bearing pressed into it.
Ordering the fan from Pelican I was advised that I should go ahead and purchase an additional Fan Hub Bearing which goes behind the fan (according to them). Removing the air compressor, drive belts, alternator connections, etc, I was able to remove the shroud complete with fan and alternator. I used a gear puller to remove the old fan and fan hub bearing in the fan expecting to find a second fan hub bearing behind the fan. But NO. There was a spacer (about 1 - 1.5") on the shaft that the fan fit over. This spacer is no where in the schematic that I was able to get from Realm.com? Has anyone out there tackled this before? Is there supposed to be two fan hub bearings? Also the end of the shaft that is held with the 12 point hex tool to remove the main 24mm bolt seems a bit worn (Stripped). Is here any other way to hold the pulley system of shaft still while tightening this bolt which is the last item on reassembly? If not, I might be up against a new Alternator. Thanks.
I can't help with the bearing info, but my alt shaft 12pt. was stripped also. I was leaving for Luftgekuhlt, & didn't have time, so I had to replace. I kept the old one thinking I can get someone (a machine shop maybe) to repair it.
Concerning the stripped socket head on the end of the alternator shaft:
I would think since the forces involved are not too high
--a strait bladed stubby screw extractor could be used as a tool to hold the shaft when loosening or tightening the pulley nut. Otherwise, I could see
--a slot could be cut in the striped end and a straight blade screwdriver bit for a ratchet wrench could work,
I know there are two star-point-ended tool specifications where for each style the points have a slightly different slope to the points. Maybe someone used a 12 point tool of the improper style to turn it. Even then one would need to use a lot of force will beyond what is required to strip the socket. Also if one was inadvertently using the wrong one it might slip and strip the fastener socket some but not to the point where
--the correct metric driver size & profile will be able to grasp the fastener and work.
Also in my experience, if the belts are adjusted too tightly one will get an occasional fan ding. I now use a Gates Krikit belt tensioning gauge and the occasional ding is a thing of the past.
Thanks Andy. All very useful info. I did try to loosen the shroud strap and also loosen the drive belts but could not rectify the ding sound. Appears like the fan had a very slight wobble. I also talked with a few performance shops in CA and they acknowledged selling 2-3 of these 993 fans every year. Apparently they can get cracks, etc. and get out of round. Would never expect that to happen to a $600 fan made of metal?
All I can remember is take lots of pictures and put things back in the order you found them as most folks end up doing the R&R twice including me! The good news is the second time is much easier.
There’s the only one bearing that’s pressed onto the fan. No other bearings behind that. All you should see is that spacer you pointed out. If your alternator shaft 12 point is stripped, you can very gently and carefully insert a padded screwdriver through the fan opening to lock the alternator in place. I’ve done this many times, no issues.
Hello Gavonder, Thanks to a response from AOW162435 and tremendous help with my cooling fan issue, I learned that a $10 investment helped solve my stripped
Alternator shaft. Look into purchasing a Stubby Square 10mm 12 point socket that seems to fit much better and just might be your answer. Snap On makes one for around $12 but I'm sure you can find a decent one at NAPA or any reputable tool stores.
Last edited by PylotJB; 11-07-2021 at 10:46 AM.
Reason: Spelling
Hello Gavonder, Thanks to a response from AOW162435 and tremendous helped with my cooling fan issue, I learned that a $10 investment helped solve my stripped
Alternator shaft. Look into purchasing a Stubby Square 10mm 12 point socket that seems to fit much better and just might be your answer. Snap On makes one for around $12 but I'm sure you can find a decent one at NAPA or any reputable tool stores.
Hello Gavonder, Thanks to a response from AOW162435 and tremendous help with my cooling fan issue, I learned that a $10 investment helped solve my stripped
Alternator shaft. Look into purchasing a Stubby Square 10mm 12 point socket that seems to fit much better and just might be your answer. Snap On makes one for around $12 but I'm sure you can find a decent one at NAPA or any reputable tool stores.
Thanks for the info, but I already have that & another one. Neither of them worked. The shaft is basically rounded inside. No rush, as I replaced the alternator. But, I would like to repair it eventually.
11-03-2021, 04:04 PM
Engine Cooling Fan
