Discussion Forum - Northstar Chevelle Club

SShink · 3K+ Club

Stuck Diff Plug-Suggestions?

John D · 2K+ Club

An old trick:
Try tightening it first!
It sounds goofy, but... 1) if it's really stuck you've lost nothing, 2) sometimes getting it to crack a bit tighter will allow you to go back/forth/back/forth and get it out.

Lost in the 60s · President

Smack it good a few times with a BFH. That will shake the threads loose. Be sure to hit it squarely.

Chris R · 2K+ Club

Use an extension and hit the end of your extension to get it good and seated in there and also loosen up the threads. That way, you still have the square left so it doesnt get mushroomed out if the extension wasnt there. It wont be quite as hard of a hit on the plug since your extension absorbs some of the impact. But you wont turn the end of the plug into a pancake. It would also help to spray some penetrant on it.

On a different note. Its my understand from things I have read in the past. That those red "Diff lubricant only" tags are quite collectible with the 100 point restoration guys. Mainly because they are always missing. I see yours has one, and one that looks like its in good condition. Totally cool.

SShink · 3K+ Club

Chris R wrote:
Use an extension and hit the end of your extension to get it good and seated in there and also loosen up the threads. That way, you still have the square left so it doesnt get mushroomed out if the extension wasnt there. It wont be quite as hard of a hit on the plug since your extension absorbs some of the impact. But you wont turn the end of the plug into a pancake. It would also help to spray some penetrant on it.
On a different note. Its my understand from things I have read in the past. That those red "Diff lubricant only" tags are quite collectible with the 100 point restoration guys. Mainly because they are always missing. I see yours has one, and one that looks like its in good condition. Totally cool.

John D. told me last night he as a 3/8 extension that the ball broke off the end, and he ground it flat, so Chris I may try your method using that.

I was surprised by that posi tag too. It's the first time I really got up in that area to do anything, and saw it there. I thought there was supposed to be one on the rear diff cover?

Dave Seitz · Mega Poster

Get some good penetrating oil on there as well, if the tag was not on there I would say give it some heat.

Bungy L-76 · Active Member

I'll toss in my 2 pennys worth and just echo what others have said. Hit it with a hammer and try tightening it first. Usually the "corners" of those plugs are good in the tightening direction and you can break it loose. For last resort, a torch.

I know they reproduce those tags if you mess that one up. I also think the older cars had the tag on the diff cover. Not sure but that's what comes to mind.

OscarZ · Treasurer

My 1978 Cutlass still had the factory silver metal tag on the differential cover. I think that continued on for years but it just wasn't as common outside of trucks to have a posi so it got even rarer to see one.