I just checked the oil level in the differential on my 77 Vette, and when I replaced the threaded oil plug, I noticed it doesnt' thread all the way down flush with the differential. It gets tight and doesn't appear to be leaking. When it's tight, the red tag moves freely. I was just wondering if it should have a crush washer or o ring on it, or if this is normal???? Thanks,
Kenny

 

normal it's a 3/4 npt plug

 

That is normal for your plug. The plug has a tapered pipe thread and even though your plug has a flange on it, the plug will never go in and shoulder on that flange.

 

Thanks fellows, I probably asked some dumb questions on here, but I always like a second opinion on this car from you guys that have a lot more experience with them than me. Even though I'm 51 years old and have tinkered with cars and motorcycles all my life, this is my first Vette and I'm still learning. I've already learned that there's a lot of things on these Vettes that are just a "little" different from other cars. Thanks again,
Kenny

 

Kenny, not only are they just a "little" different from other cars, they can be different from one year Corvette to the other. So, it always pays to ask