Viscous Coupling

[Mad Mart]

How do you get at the bearing? I've taken the viscous bit off the front & can see the bearing at the back. Do you need a press to push the shaft out?

[whydidistartthis]

The couple I have separated, just needed a few sharp taps with a hammer and punch. Think I even had an assistant hold it for me, so as not to damage the viscous part.
I was surprised how easy mine came off!

[Carl]

I was surprised how easy mine came off!

So are those who've had to retrieve them from a lunched radiator

[JPB]

Just how much fuel can a viscous fan actually save I wonder? Consider the frictional losses in the fan clutch, the extra weight over a fixed fan and the impact that occurs when the coupling engages. Still, if it's right for the car then it has to be done I guess. Just make sure to apply some Loctite between the hub and the blades.

[Mad Mart]

A slight misunderstanding perhaps. I have already removed the ali viscous bit that has the bolts for the fan blades, that's the easy bit. The bearing (or bearings) is/are in the bit with the pulley on. It looks like it's sealed.

[Magenta Auto Sprint]

The bearing on the back of the pulley is made complete with the shaft. the bearing looks like two bearings pushed onto a shaft but it is a a long body with a row bearings at each end and with the a long shaft acting as the inner bearing. Looks like a speacilly made part.

Malcolm

[straylight]

this is from the deep cycle memory banks mart, so take it with caution

When my spot welded fan gave way, it tore apart the pulley, which fractured the steel cylinder pully part 2496 iirc. I had another pulley machined up in the patrol boat base in Darwin and replaced the bearing with a new one, reusing the "back plate" part of the pulley. I'm reading from my parts book where I dutifully wrote down "The holden red water pump bearing (CBC bearing Co) fits into UKC2496 pulley assembly after a little machining". By little, I recall it was just a smidge and I seem to remember the bearing was pressed into the back plate of the pulley assembly. I had access to a press back then, so likely it was a pretty tight fit.

The holden red water pump bearing refers to the "colour" ID of a GM engine, popular in Australia in the 1980's, fitted to holdens. I reckon I walked into the CBC shop with my old bearing and they matched it closely with the Holden one. I can do some more research and find out the CBC part# if you need.

The reason why the viscous drive, from my experience, is that if they are welded up, they place too much stress on the pulley and eventually, in my case the pulley broke. Probably when the pulley bearing seized. The other option is for the tolerance ring to fail, sending the fan into the radiator. They make a cracking noise when they are welded up, 3rd to 2nd wakes everyone up Mine made an even more impressive noise when it let go.

stu

[Mad Mart]

Cheers guys.

I thought seeing as I had nothing to lose I'd have a go at dismantling it.

The centre spindle does need removing with a press. I was doing ok with my drift but then I took a small chunk out of the pulley, so I thought sod it & carried on hitting it through.



It didn't actually take long to get it apart & would take about five minutes using a suitable press.







On the end of the shaft is stamped 'FPS889' (possibly a 'B' rather than a 'P'). RHP Bearings on the ends of the bearing. The shaft looks like it also needs to pressed out (I can't see anything holding it in place).

ID = 15.9
OD = 30
Len. = 38.8

[Magenta Auto Sprint]

Martin,
The shaft does not press out, it is an integral part of the bearing, if you squeeze the outer bearing in the vice it will break to reveal two sets of bearings, one at each end of the shaft.

You could have a spindle made up and order sealed bearings to suit.

[Mad Mart]

Yes, sorry Malcolm, you did say that earlier.