fan bearing replacement - save some money

chancecasey · 07-09-2006, 02:12 PM

I could not remove the fan by holding it and tapping the shaft - and I "tapped" that sucker really hard with a brass drift - hope I didn't mess up the alternator. Anyway, what I resorted to to take the fan and the hub off was a 6-inch gear puller from Kragen's. The tongs just fit inside the rectangular holes in the fan and wouldn't you know, the number of holes was a multiple of 3 so that 3-tong puller fit just great.

Anyway, not sure if this applies to earlier engines but on the 3.6 the fan bearing is part of a sleeve/collar and the whole thing costs about $130 or more. What a ripoff. Unfortunately, the bearing is held in place by a snap ring that is apparently designed NOT to be taken out. No worries, just put a dremel cutting disc in there and take out enough material of the snap ring, opposite of the gap, and you can just pick the destroyed ring out.

I'll post my progress later this week in hunting down a replacement bearing from a bearing warehouse (hopefully they have the size) and a suitable replacement snap ring. If it all works out I'll get out of this WAY cheaper than $130.

chancecasey · 07-10-2006, 09:34 AM

Ahahahahahaha! How FOOLISH of me to think I could outsmart Porsche. That bearing was custom manufactured for Porsche only and you CANNOT get another one of the same dimensions ANYWHERE - including INA, the oem.

I could buy two (single row of balls each) with a slightly larger O.D. and less thick, stack them, and machine out the hub to accept them, but that's $50 in parts and the hub's wall thickness would drop from about 3mm to 1.5mm. Not sure if I want to go to the trouble at this point. What a bummer.

id911T · 07-10-2006, 12:14 PM

In situations like this I always wonder why those bastards didn't just design it to use a standard bearing.

chancecasey · 07-10-2006, 12:53 PM

It's either just poor design - engineers making more work for themselves by convincing the suits that standard bearings just aren't "good" enough, because they're too lazy to go back and redesign the stupid hub AFTER researching what bearings ARE available,

or

Porsche wanted to control the entire supply chain to get that business,

or both. F-ers!

BoxxerSix · 07-10-2006, 06:50 PM

I beleive the bearings were designed as not only a standard ball bearing to take the load of the belt tension, but also as a thrust bearing to take the direct load from the fan itself. The fan pulls in a tremedous amount of air at RPM and thus has an equal load force pulling back on the fan and bearing.
If the bearing had no way to take this sort of side load it would just eat itself alive during high RPM operation. Basically the same principle behind a turbocharger's thrust bearing for the compressor wheel.

Thus the rediculously expensive price, and of course OEM exclusivity.

chancecasey · 07-11-2006, 08:46 AM

Well, when you look at the thing, it's just your standard-looking bearing double-sealed design - with either needles or double-row balls as it's rather thick from front to back. Perhaps there is something non-standard going on inside. Anyone is welcome to take my old one, rip it apart, and take a look. I'd make the argument that there are plenty of old GM fans that put comparable load parallel to the shaft, but I don't know for sure.