Hi - I’m not a Lexus owner so this is my first visit here but was doing an oil change for an impoverished relative today and found a metal disc lying on the oil filter access panel, which since the car has gone home I’ve established is from the front of the air con pump pulley, so I hope I can prevail on someone here to help. Car is a 2010 IS220d

The disc has an internally threaded boss - does it simply screw back in place or is there a secondary fixing missing? What is its function? I can’t see anything that appears to lock it in place missing on an internet search…




Thanks in anticipation,

Martin

 

Does the AC compressor freewheel if spun by hand (not the outer belt) but the inner core? Does AC work?

Bad angle for viewing front clutch but this came from my 2010 Tundra. I don't see that part being from the AC clutch but don't know what else it would be.

 

Thanks - I found a picture of one on eBay showing an identical disc so I’m certain it’s come from hers. I’m assuming it’s been running like that for a while but she hasn’t any idea whether the air con was functioning because “she never uses it”…😳

I’m guessing the seals will have dried out long ago.

I’ll check it out next time I see the car but was hoping for some confirmation that it doesn’t hold the pump pulley in place! I can’t see it coming off with the belt locating it though.

 

When the a/c is not being used, the serpentine belt simply spins the pulley on the air conditioning compressor, while that disc remains stationary.

Electricity flows thru a coil ring behind the pulley when the air conditioner is being used.

This electricity creates a strong magnetic field which attracts that disc, the disc then gets attracted to the pulley and the internal components of the compressor will then begin to spin. This creates the cooling effect of the system.

Looks like you're missing the center bolt which secures that disc to the a/c compressor.

Also looks like you're missing the shim spacers.....the shim spacers will place the disc 3mm away from the a/c pulley.

The disc is referred to as "a/c clutch disc".

Below is a generic diagram of typical a/c compressor related components.........give you an idea of what you're missing.

Left to right: Retainer nut/bolt>clutch disc>shim spacers.

 

The air conditioner will be used any time she uses the defroster. The way defroster works is:::::::: Cold, damp air is vacuumed into the HVAC system. The air conditioner cools this cold damp air even more resulting in the moisture becoming condensed/expelled. The air is then heated, the moisture is removed from this air as it's pushed back into the passenger compartment.....then recirculates, repeats.

Regarding the seals......they will not have become dried. The seals are inside the compressor housing, not outside by the pulley or disc.

Get a new disc with installation kit (bolt & shims) install disc with shim clearance totalling 3mm. This will allow the a/c and defrost to operate properly.

 

Thanks - some excellent info and I can now understand the function of the plate. What isn’t clear is the purpose of the internal thread and how the plate is fixed to the input shaft of the compressor.




For clarification, it’s a Denso unit and the following is a picture of an assembled one I found on eBay. Close inspection suggests the area around the centre is part of the plate.


Does the small hex headed component carry a larger external thread for the plate?