I have an 87 Camaro rear diff. that I am using on my hotrod. My question is, on the top of the rear just as the housing transitions into the axle, there is a small hole that is not threaded. Looking down into it I can see the axle. Is there a plug of some sort that goes into this hole? I know something has to fill it, just want to know what the hole is for and any suggestions of what to put in it.

 

its on the right side? its a vent, there is a plastic vent fitting that goes there.

 

Yeah, right side top near the axle bearings I believe. Is this a parts house type item or more likely a dealer part? Does it have a check valve in the line or just a straight line to the outside? Thanks for the help.

 

you should be able to get it from a dealership, if not classicindustries # G6028 $3.95
should be a 7/16 hole