Viscous fan pulley help !

Good morning OKA owners
Alan needs some mechanical advice on how to
(as easy as possible)
to remove a viscous fan pulley nut to replace the unit
I have some photos of the unit
please help
thanks regards
Jo

Jo and Al, that looks a bit odd to me. You seem to have a different pulley with 3 belt grooves.

My XT viscous hub has a bolt on shaft like the manual shows, and my blades are on the radiator side of the hub, not the pulley side:



Are there no bolts inside your pulley? The viscous hub will/should rotate about that nut of yours.

I've checked the Davies-Craig catalog and don't see one like yours.

Suggest you call them or maybe Alan at Oka Parts and get some advice.

FYI, my viscous hub stopped working last year (which is why I was locking the pulley to the hub) and in many cases they are repairable (just need refilling with cheap viscous oil) so they don't have to be replaced. I've just done that with mine but haven't done enough kms yet to confirm it's working again.

Thanks David
Have some others suggestions that were a huge help
The neighbour was right and has been confirmed that is a left hand thread
(Hmmm...said Al )
No idea how much the replacement unit was. Invoice has disappeared .
Thanks regards
Jo

yes LH thread on the nut and "usually" the belt tension should hold the pulley while you undo the nut.
David your fan setup appears to be different to all I've seen or maybe it is an XT setup. All the LT's I've seen have the nut setup.

Peter, my fan set up looks exactly like the XT manual.





I assumed Jo and Al's Oka 159 was an XT. Maybe it's fitted with an LT fan pulley?

Tie a knot in the end of a length of rope. Wind the rope around the cylinder trapping the knot and continu for several more turns and then tie the rope off to the chassis.

Just have to figure out which direction to wind the rope.

I use the same method to get oil filters undone, except the free end of the rope is tied to a large screwdriver which is used against the filter body for leverage.

I have the same viscous fan setup as you Jo and Al, i have an xt. And no, the belt tension wasn't enough to hold the pulley still, AND there's not enough room for a spanner anyway (i could grind one i suppose). i have to undo the four bolts numbered '1' in the parts diagram posted by David above with a 1/2" spanner 1/6th of a turn at a time = PITA.

An old thread but worth adding to the knowledge base.
I have just removed the fan / coupling from 191 (coupling is suspect) and have found that as reported elsewhere on this site the previous owner (Keith Harris) had installed a Ford fan, not sure what model but probably Falcon, Ford part no 870A-8600-AA. This is the number molded into the fan. I believe this fan is larger diameter than the original and was probably fitted to improve cooling (bit marginal in a XT).
The coupling itself is labelled TOROFLO 115063 090709C. I have been unable to find any info on this part and don't know if it was from a Ford or not. It is not a repairable part.
This fan / coupling uses the LH threaded attachment, as others have said the belt tension is not enough to stop the assembly turning but a large strap spanner worked wonders.

John it might be worth taking it into an autoparts place hopefully with an older assistant that has been around for a while and they might recognize it. If it is from a Falcon it will be an older model in the E"X" series as the later ones mostly had electric fans.
Have you tried ringing Keith?

Thanks Peter

The Ford fan looks as though it has been modified where it bolts to the coupling (it has clearly been attacked with an angle grinder to remove something-or-other) which makes me suspect the fan & coupling came from separate sources.

Probably time for a trip to the wrecker's to see if I can ID the coupling. I'm sure it's not original, could even be a replacement from Paul N? That's another option for info, worth trying him first.

In any case the fan info may be of interest to others who wish to increase the fan size (as I think David did not long ago). One of the bits had a 1990 date stamp, this would put it at about Ford EA, I think, which would align with your estimate of the model.

The coupling is suspect, 191 is tending to overheat a bit on long hills and I can't hear the fan cutting in when it's hot. I'm pretty sure the temp gauge is OK, it was replaced recently (story there too, almost certainly a wiring fault from when 191 was first built which caused someone to install a capillary-type gauge which I replaced.) The temp warning lights up in the range 95 - 100 deg C which also confirms the gauge is probably OK.

There isn't much resistance to rotation when cold although some couplings apparently have a system to stop the usual initial few minutes of the fan running when cold, so that's not a 100% certain test. I was intending to do the usual repair of adding some silicone oil but then discovered the coupling is not dismantle-able. I have confirmed the bimetallic strip is operating and rotating the control valve spindle although it was full of crud at first.

I'll see how I go......

It's a while ago when i had mine off, but i think i used an xf falcon coupling. From memory i had one spare and it fitted... could be wrong.
cheers, alister

I put a new hub on just before I removed the perky. $50 if you want it.
Rob

Thanks Alister, Rob & Peter
I've now confirmed the coupling is faulty and need to go to Melbourne today for a funeral, so I've arranged with Paul N to drop by and get a replacement.
Paul tells me the one he stocks has different behaviour to the original Oka one and also to the Ford one, which makes it better in the Oka (less fan revs at normal temp than original = less noise and power wastage, and also cut-in temp is better suited to the Oka thermostat and temp alarm settings). He also confirmed the model numbers (EA etc) for the Ford fan so that's also useful info.