chode

Hi all,

As my fan bearing seems a bit lumpy I've been considering switching to the RS style single pulley alternator / fan setup (as pictured). Instead of buying the part I want to try to turn my own on a cnc lathe...

Anyone know if this should be an easy job? Would Aluminium be suitable or is it too soft?

Thanks!

Garth S

The RS hub is of aluminium IIRC - can verify later.

The OE hub has a circlip retaining the bearing: I had pressed the bearing out, and had planned to cut & tack in place a solid replacement insert to emulate the RS hub - insert three M6 studs vs allan bolts, and ready to go ....

Then, a real RS hub materalized, so I never finished the DIY. Anyway, that is a simpler route to follow, if you wish.

Stealth 993

The hub is simple, you should be able to do it.

As stated it's already Aluminum.

chode

Thanks Garth,

I removed the circlip and pressed out the bearing yesterday. Checked around and had no luck finding a replacement bearing - apparently its now 'obsolete'..

I like your idea of using the existing bearing housing and inserting a new fixed collar in place of the bearing. Were you suggesting tack welding the new collar to the OE hub - without the original circlip im concerned that the fan could slip off the hub if my tolerances are not tight enough.

Finally what is the big advantage of M6 studs over the old allan bolts? Is it just for convenience? I've noticed that the RS hub has the bolts fixed in place but I dont see much advantage over this.

Scott

Garth S

No need really to tack the insert in place: with the OE spacer against the bearing, the end nut on the shaft holds the package in compression on the alternator shaft.... that is also the way the RS hub is secured. If you turn out a piece /insert on the lathe, may as well add the spacer dimension to it to end up with a single piece. The 3 bolts secure the fan - and the 'nut' secures alternator rotation.

The cheese head/allan bolts are a major PITA to remove for belt service .... especially if caught on the roadside with a failure ( I've had to cut into the heads with a cold chisel to shock them loose). With studs, all one needs carry is a 10mm wrench or socket vs a 5mm allan key that is intent on rounding out the soft & shallow allan heads .... and with studs, it is easier to play with the shim stack when setting (single) belt tension.

chris walrod

As Garth mentions, I very much prefer the studs!

chode

Just as an update, I made the RS hub as discussed and it works perfectly. I've attached a few pictures below to clarify...