Editing A/C adjuster/idler pulley bearing replacement

[[Category:Engine]]
These pulleys are considered non-serviceable, they're also NLA of course. EFI Solutions sometimes has stock, but at time of this writing not so. They'll set you back the better part of $150 for a new unit (but come complete with new mounting hardware). The usual failure is the bearing wears out in the pulley ~ this is a standard 6301 LLU bearing, so less than $15 each. The trick is removing/replacing the bearing, in a part not designed for that service.

The problem: if you look at the front (radiator side) of the pulley ...where the bearing was pressed in, there's a small return flange that gets  peened over to capture the bearing outer race....

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If you know what a 6301 bearing shoulder looks like, you pick it up straight away, but if you measure it a 6301 has an OD of 37mm, but after that lip is peened over the measurement of the opening is roughly 36.3mm ....so there's 0.5mm or so of the bearing outer shoulder captured.

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Above you can see the clean/covered metal of the bearing shoulder where it's held by the flare, versus the rust surface open to the elements,

What we did was mount the pulley in the lathe, and just turn off enough of that peened flare to clear the OD of the bearing. Then mount the pulley in a press supported by 60mm OD pipe and using suitable size drift to push the bearing out.

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Re-assembly is pretty straight forward ~ just ensure you get a 6301 2RU bearing (a ZZ shielded type won't do, must be sealed & self lubricated). 

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Provided the belt/pulley all align correctly, there should be no axial thrust on the bearing and loctite 641 will hold it there (it can't walk out far anyhow because of the cover-plate). So this is standard procedure ; apply loctite to pulley bearing hole, support pulley boss under bearing, press in new bearing using a suitable sized drift (36mm OD is ideal)

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Refit to  car, adjust belt tension, good to go ~ new bearing cost was $11.65 retail (bit under $8 trade). Quick fix, and now that it's done, I no longer hear/feel this strange vibe coming from under the bonnet somewhere that's eluded me for a while ; last time I checked that pulley bearing 5 years ago, it was fine...seems they can go to pot in short order after the 30 years in service mark  =)