Head to toe service while SORNed.

[Britprius]

I am about to change the engine coolant pump as part of the service. When I have the drive belt tensioner pulley off the car It would be prudent to replace the bearing in the pulley. Does anyone know the bearing number "not the Lexus part number for the assembly" so that I might buy a bearing to press into the pulley while I have the pulley off the car. 
It may be that someone has changed the pulley, and has the old one in there garage they can check on for me. If the bearing number cannot be seen the bearing dimensions "bore, outside dia, and width" would allow me to trace the correct bearing. This is for a GS450H 2006 till 2011.

Thanks John.

[ColinBarber]

The Lexus part code you don't want is 16620-31060. Googling that comes up with pictures showing the bearing which may help but not sure how reliable this is.

e.g.

https://www.ebay.com/itm/PULLEY-TENSIONER-KIT-Febest-0187-GWS191/254411910981?epid=214938063&hash=item3b3c21af45:g:wFAAAOSwsnVdwYsL

[Britprius]

3 hours ago, ColinBarber said:

The Lexus part code you don't want is 16620-31060. Googling that comes up with pictures showing the bearing which may help but not sure how reliable this is.

e.g.

https://www.ebay.com/itm/PULLEY-TENSIONER-KIT-Febest-0187-GWS191/254411910981?epid=214938063&hash=item3b3c21af45:g:wFAAAOSwsnVdwYsL

Thanks Collin. After much researching, and confirmed by your picture the pulley uses two  6203RS bearings that are readily available at £2 each depending on how many you buy " this can go down to 85 pence each for ten bearings. This makes a saving on the OEM part of over £50, and on the aftermarket versions of between £14 & £30.
If you look closely at your picture 6203RS is imprinted on the rubber seal, and from my research there are two bearings pressed into the pulley, and a metal tube pressed into the bearing bores. The bearings seem to be the same on most Lexus models, and when used to tension the belt internally on the belts with ridged pulleys use two bearings. Where external plain idler pulleys are used on the back of the belt they take only one bearing.
I have ordered four bearings delivered for £5.01 to give me spares for the future.

For reference the tensioner bolt is a lefthand thread while idler pulley bolts are normal righthand thread.

John

[ColinBarber]

13 hours ago, Britprius said:

If you look closely at your picture 6203RS is imprinted on the rubber seal

Yes, if you click on the picture it will display a larger version where the number is clearly visible. My concern was they had just used a generic picture rather than the actual GS one. Once you have received then please can you confirm they are the correct ones. 

[Britprius]

16 minutes ago, ColinBarber said:

Yes, if you click on the picture it will display a larger version where the number is clearly visible. My concern was they had just used a generic picture rather than the actual GS one. Once you have received then please can you confirm they are the correct ones. 

When the bearings have arrived, and I remove the old bearings I will confirm if they are correct or not.
I have looked at many pictures of the two types of pulleys even from different Toyota/Lexus engines, and all I have been able to positively identify use the same 6203RS bearing. The RS designation is for rubber seals "metal seals are available".
The bearing dimensions are :- ID 17mm, OD 40mm, Width 12mm.
I know changing the bearings in the pulleys does require a little extra work, but the savings are substantial given that it would be very unusual to find a pulley that is otherwise unusable apart from physical damage. 

John.

[Britprius]

The bearings for the tensioner pulley arrived today so I decided to do this part of the coolant pump replacement. Only one lefthand "clockwise to undo" threaded bolt to undo, and the pulley was off. 
After pressing out the inner sleeve from the two old bearings then the bearings from the pulley I can now confirm that the 6203RS bearings are the correct ones to use. The old bearings although having no play in them were obviously past there best at circa 145,000 miles sounding very dry when spun. The new bearings when fitted in comparison as expected were very smooth, and silent in operation. Total cost of bearings  £2-50 so quite a saving on Lexus pulley prices.

I have yet to remove the coolant pump "a job for tomorrow", but the pulley on the pump has a small amount of side play, but know sign of leakage. This pump was identified by Lexus main dealer as needing changing 50,000 miles ago. I have fresh Toyota SLLC coolant ready to go in after fitting the pump.

John.

[Farqui]

Well done John, the bearing part number has been duly noted 😉

[Britprius]

I changed the coolant pump today along with the tensioner pulley with the new bearings fitted. The job was easier than anticipated once the many hoses to the thermostat housing, and the housing it's self were removed along with a couple of plastic tidy panels on either side of the engine.
After the injection ECU is unbolted from the front drivers side of the engine, and swung out of the way on it's wires the many bolts holding the pump could be removed. These come in two sizes with 10 &11 mm spanner size heads. All the 10 mm are the same length and all the 11 mm are the same as each other but longer than the 10 mm. This means the bolts cannot be fitted in the wrong places making reassembly easy.
After removing the pump internally the pump, and the engine block looked as new with no signs of corrosion.
The new pump was fitted, and fresh Toyota SLLC coolant installed. There were no problems with bleeding out air. Just run the engine, and top up the coolant as air bubbles rise, and coolant level goes down.
Some may ask why I did not change the thermostat while I had the housing off, but this is easy to change at any time, and I see no reason to replace a working item.
The engine when standing at the front of the car with it running is noticeably quieter "no dry bearing rasping sounds".

I drained, and refilled the inverter coolant fluid to complete the coolant part of the service.

Items left to do are differential oil change, and gearbox oil pump electric motor bearings. My problem is I have to do this on ramps so far from ideal.

John.