Rear End Fill plug

[fredhouse]

I replaced my brake backing plates today so i needed to drain and refill rear end fluid.I learned today you should always open the fill plug before you touch anything else.Why would they put a steel plug in a aluminum housing.3 hours later i have a new plug.2003 trailblazer 5.3L

 

[The_Roadie]

I messed mine up so much last time I ended up getting a fill plug (O2 sensor bung) welded at the right height into my diff cover plate. I hate the insane recessed square design, and the ease of overtorquing it on installation.

 

[fredhouse]

I replaced my plug but did not use the recessed square design,i will never have this problem again.

 

[CaptainXL]

I've never tried it but heard that you can put the extension in the plug and rap on it a few times with a hammer and it should come right out.

 

[TangoBravo]

I've never tried it but heard that you can put the extension in the plug and rap on it a few times with a hammer and it should come right out.

Has work for me twice. The other times it didnt help at all.

 

[Billdaman]

I replaced my brake backing plates today so i needed to drain and refill rear end fluid.I learned today you should always open the fill plug before you touch anything else.Why would they put a steel plug in a aluminum housing.3 hours later i have a new plug.2003 trailblazer 5.3L

I purchased the SK SKT41242 1/2'' Drive Male Pipe Plug Socket 3/8''. It worked beautifully. I squirted PB blaster to remove the scale and rust from the fitting and the socket fit tight and perfect. All the research I did told me this was the only surefire way to avoid the problem. My truck is 9 years old and in the northeast and had never had its fluids changed in over 100K. No problem with either differential fill plug with this socket. A little pricey though

 

[gmcman]

I've never tried it but heard that you can put the extension in the plug and rap on it a few times with a hammer and it should come right out.

Didn't work for me. With the stock rear I had, I ended up taking a short 2" extension and let the bench grinder give it a face lift. I squared the end so it would sit deeper in the plug but unfortunately that was after I boogered up the fill plug from the extension with the rounded bottom.

Good thing I had the vent tube

 

[Billdaman]

Didn't work for me. With the stock rear I had, I ended up taking a short 2" extension and let the bench grinder give it a face lift. I squared the end so it would sit deeper in the plug but unfortunately that was after I boogered up the fill plug from the extension with the rounded bottom.

Good thing I had the vent tube

I forgot in addition to the SK Male Pipe thread 3/8" socket I sprayed the threads with PB Blaster and not a single worry or problem on either plug, well worth the investment

 

[buster04]

I messed mine up so much last time I ended up getting a fill plug (O2 sensor bung) welded at the right height into my diff cover plate. I hate the insane recessed square design, and the ease of overtorquing it on installation.

After all the years you would think some engineer would learn not to mix a steel plug with a aluminum housing. I ended up with the same plug in the cover set up after about two hours of f'n around with the original plug...

 

[Wooluf1952]

After all the years you would think some engineer would learn not to mix a steel plug with a aluminum housing. I ended up with the same plug in the cover set up after about two hours of f'n around with the original plug...

An aluminum plug can weld its self to an aluminum housing.
I used to build explosion proof motor starters. The housings were cast aluminum and the pipe plugs were steel. We had the same problem with s.steel nuts on s.steel studs.