Viscous Coupling Part Number

[E3_UK]

I'm gathering the parts to convert from mechanical to viscous fan coupling (using the original 4 bolt water pump fitted with adaptor flange) at the moment. The OEM listed part number for the coupling is 11521260459, also listed (on RealOEM.com) for various other models (E21, E12, E24, E23). Searching Ebay (UK) for a cheaper alternative (203 Euros on Walloth) using these other models (searching under E3 produces no viscous couplings) produces couplings with lots of different OEM cross references, none of which match the original number, which is confusing. Can anyone help identifying which alternative part number would be correct ?
Thanks,
Robin

 

[chope97]

E23 733i

I don't know if this helps I used a viscous coupling from a 733i including fan

 

[E3_UK]

Thanks but it's still not clear. All of the viscous couplings I find have a single central female nut for mounting to the pump. I have the original type pump with 4 bolt flange, therefore have ordered the adaptor flange and bushing (items 6 and 8 http://www.wallothnesch.com/motorteile-kuehlung/bmw-2500-3-3-li-e3/katalogbild-11-24.html). This requires a coupling with a central through hole. Did you change your pump to one with a single male thread to allow fitting a coupling with the female nut ?.

 

[E3_UK]

I think I see the problem. I need the setup shown here http://www.realoem.com/bmw/enUS/sho..._1982_E23_BMW_732i&diagId=11_0621#11521706619 to enable the later coupling to be used, so I've ordered the wrong parts. Walloth want 203 Euros for the coupling to original spec', no way I'm paying that when you can get the later ones for a fraction of that price.

 

[Luis A.]

I think I see the problem. I need the setup shown here http://www.realoem.com/bmw/enUS/sho..._1982_E23_BMW_732i&diagId=11_0621#11521706619 to enable the later coupling to be used, so I've ordered the wrong parts. Walloth want 203 Euros for the coupling to original spec', no way I'm paying that when you can get the later ones for a fraction of that price.

But...you realize if you go with this later viscous coupling that has the single large female thread you will have to replace your water pump to be the one with the large male thread, like this:

 

[E3_UK]

But...you realize if you go with this later viscous coupling that has the single large female thread you will have to replace your water pump to be the one with the large male thread, like this:

Yes I know, that's why I think I'll just leave it as I've just fitted a new pump. I've had the radiator chemically cleaned to remove sediment, fitted a new pump, thermostat and hoses. I'll also lock the fan clutch. Hopefully the sum total will help. If I can find the correct viscous clutch later on I'll change it then.

 

[E3_UK]

Just tested the mechanical clutch assembled on the car. Poured hot water over the fan element and surprisingly it locked up solid, wasn't expecting that. Might just chance using it as is now.

 

[E3_UK]

Well, having re-assembled everything the car now runs at normal temperature so the cumulative effect of cleaning the radiator and replacing the water pump, thermostat and hoses seems to have done the trick. I'll postpone the viscous fan upgrade for the moment to see if it continues like this.