My camaro has howling under deceleration.

Starts at about 20mph, gets worse the faster I go.

I am guessing I need to tighten the pinion nut a bit.

Seeing as I've never taken apart a rear end, should I attempt this?
Or give it to a shop to work on?

I live near fbody central, has anyone dealt with them?

 

Just get under there and tighten it. The crush sleeve takes a lot of torque to crush and I doubt you can crush it with hand tools. I did my pinion seal last week and my 250lb self was hanging on the ratchet when I tightened it and it works fine for me.