V8 tensioner pulley part number weirdness

[AKmoney]

Hi all,

The serpentine belt tensioner pulley bearing was getting pretty loose on my 4Runner so I decided to swap it out. I proceeded to remove the radiator fan (not sure if that was entirely necessary) to enable proper access to the tensioner, then removed the pulley from the tensioner assembly and brought it down to my nearby Toyota dealer. They didn't have the part in stock and the nearest dealer that did was 30 minutes away so I decided to try my luck at O'Reilly Auto Parts. This is where things got confusing.

O'Reilly calls for a Gates #38001:
Gates DriveAlign 38001 - Pulley | O'Reilly Auto Parts

We noticed this part number, at 90mm outer diameter, was smaller than the part I pulled off my 4Runner. What's interesting is the entire tensioner assembly (which included the pulley) also had the smaller diameter:
Gates DriveAlign 38488 - Automatic Belt Tensioner | O'Reilly Auto Parts

The guys at O'Reilly looked around and were able to find an exact match for the part I pulled off my truck which was 102mm:
Gates DriveAlign 36119 - Idler Pulley | O'Reilly Auto Parts

I just finished installing it and it's a perfect fit. Zero noise from the accessory belt area.

The original part number from Toyota, according to my dealer, is 16603-0W030. No idea what the diameter that number calls out is.

Anyone else run into this?

Thanks!

 

[BlackWorksInc]

There was an updated tensioner for 1st Gen Tundras (and Sequoias I believe,) forgot what the reason was. Didn't seem to be an issue with 4Runner/Land Cruisers, so that may be where the confusion is coming from?

 

[jbtvt]

For future searchers, pretty sure mine was OEM and it was an NTN 6203lu

I pulled the dust seal and regreased with a needle fitting, cured my squeal.

Edit: And oh, the reason I was searching this in the first place: pulley bolt is reverse thread, righty-loosey, came right off, no need to pull fan.