Differential Filler Port Frozen Closed

Here I am trying to finish the 60000 service on my truck (thanks to Chris4x4, I am following your instructions chapter and verse), and I am trying to remove the filler port for the differential, and it will not budge. There is a torque stripe on the bolt which lines up perfectly with the cover, which makes me doubt whether the dealer whom I paid for the 30000 service actually did what I paid them to do.

Any thoughts on how to get this off? I do not want to round off the corners on the bolt, but if I put too much more force on it, that is exactly what I am going to do. Will PB break free work on this....heat....drill out and tap a new one...

Any ideas / experiences would be appreciated.

 

Try heating it with a propane torch and then wrench it.

 

6 pt. socket.

 

6pt socket in half inch drive and 15" breaker bar. Spray some PB blaster on it and wait a while.

 

thanks for the input. I guess I am off to the sears for a new wrench and some break free.

 

Don't heat it. It's not frozen. It's just tight. Use a tight fitting socket and man up.

 

X2, get a nice big breaker bar. I use 20"er's

 

+1 for the high quality 6 point socket and big ass breaker bar Or, alternatively, high quality 6 point socket and a normal breaker bar assisted by a section of steel pipe, AKA poor man's breaker bar! Those things are basically pipe threads so there's a lot of thread crush when they're over tightened. (the threads become progressively shallow near the back of the plug so they bottom out when tightened, good for sealing in the oil bad for removing when over-tightened) Add some surface rust, a lot of time and they're a bear to get loose. A good fitting 6 point socket and some force will almost always do the trick.

 

Tight socket, breaker bar, and PB Blaster. Let it soak a little bit. If that fails use a heavy impact wrench and get yourself another bolt... $10.

 

I have always used a 50/50 mixture of acetone and auto. Trans fluid to break free tight or rusted bolts.

Works better than all store bought lubricants.

 

Also,... you could set up a bottle jack under the wrench handle for breaking the plug free... worked for me.

 

The torque mark lining up might not be a bad thing. When I changed rear diff fluid on my truck a few weeks ago, I used my torque wrench and when it clicked, the two paint marks on the plug and diff matched up just like they had before. So it might have been a competent tech that did the work last time. With a new crush washer, those marks mean you can re-torque without even using a torque wrench.

As for freeing up your stuck plug, I agree with heat. I would first drive the truck around and get the rear diff hot, then try taking off the plug. Sometimes that's enough. Otherwise some PB Blaster would be a good thing to try. Don't know if I'd "man up" and go with a huge breaker bar, except as my last resort. If the wrong thing lets go, you're in a world of additional complications. :-/ Be ready with drill bits, taps, thread chasers and magnets.


But, try the simple stuff first - hot diff and a good PB Blaster soak.

 

Be sure to clean the area around the head from dirt, sand, grit, etc, so the socket can get a good grip.