I have a 1984 Ford F-150 4x4 and I am having trouble removing the rear differential fill plug. The fill plug is really rusty and there is almost nothing left of the square hole in the center I tried turning it out and the 3/8 drive extention wants to slip in the hole. What would be the best way to try to remove the plug?

 

I had one the same way on a old 88 chevy truck. I got it out by heating it red hot(with the differential cover off and all of the fluid out because gear oil burns gooooood!!) and hitting it counterclockwise with a sharp chisel. Always keep a fire extinguisher around just in case. If that doesnt work, drill a hole in it and use a large easy-out to remove it (again with some heat). Then go to the hardware store and get one with either a square head or hex head and put teflon tape on it so it wont happen again.

 

I would try an easy out first.If you cant get it with that then just drill and tap the plug and use a plug in there.Or,you can leave it alone and just install a fill plug in the top of the cover.Any auto parts store sells the B&M plug kits.

 

I'm thinking about putting a bolt in the hole of the plug and welding it to the plug. Then trying to turn the plug out with the bolt. The heat from welding it should also help break the plug loose. I know I have to watch how hot I get the differential housing because of the seals and the fluid in it, but I think this will work. What do you think?

 

It may not be rusty, some people put them with loc-tite and if so you need heat to release the loc-tite.

 

Try using a sharp chisel and hammer and make a notch in the direction to loosen it and then use a dull chisel in the notch to loosen it. The blows from the hammer will help loosen it.

 

Any other suggestions for getting the fill plug out?

 

Yep I am going through the same thing here in Kansas. I will post something that works. Good luck if you run into this nasty little surprise...

 

Mine stipped really good. So there is no way that plug is comming out, stupid ford for putting it so tight. Anyone think of buying an aftermarket cover with a fill plug on it. 172,000 miles on the original oil so i really need to get it changed!

 

The factory uses red loctite. A little bit of heat wrench and an EZ-out and she'll spin right out.

-Joe