Midwestdrifter
Engineer In Residence
Lightly lever, or push/pull on the outer ring. Does it move more than 1/64"? Then its time to replace.
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Pulling the seal with the fan in the way requires a low profile tool: I used a Lisle 58430, and you won’t have room for a cheater pipe from underneath, so have something planned to brace against to get the last 1/4 turn of bolt.
Maybe the factory tire jack, or even a floor jack under the ratchet or breaker bar handle? At that point the specification is degrees, not torque.
vic