Trouble removing front differential fill plug

[Mr T]

Folks:

I've posted about my noisy front differential and got good feedback about diagnosing it. One idea is to pull the drain plug and see if I have metal shavings. Well, last fluid change I could NOT get the fill plug out of the diff. I stripped it rather bad and eventually just filled it via the drain plug and a pump hose. Messy and not accurate.

Anyway, I want to remove this blasted rusted or frozen plug so I can see what my oil level is and refill after I drain and inspect the magnet. Issue is, it is really frozen. Let me tell you what I've tried and please give me some feedback on what more I should do.

1) Sprayed it with PB Blaster (or equivalent) solution and let it soak for a day.
2) Bought a reversed thread bolt remover kit. Works GREAT. It takes a solid purchase and no more slipping.
3) Put a breaker bar on there and pushed--until I broke my breaker bar at the head. Yeah, it wasn't a Snpap-on (Harbor Freight crap). So it's gone.
4) Remove the vent tube and put it out of the way.
5) Took to some heat and pneumatic impact wrench I used to remove lug nuts. Heated the outside of the area around the bolt--tried to avoid the bolt--to what I measured as about only 200 degrees. I have a laser temp device so I'm sure I was about that hot.
6) Put on the impact wrench on again and had run for at least 15 seconds.....NOTHING.

To my question: Do I heat only the surrounding area and NOT the bolt its self? I's a very large bolt with a wide area of threads. I assume I need the heat the case to expand the diff threads so they enlarge while the fill plug threads stay cold and thus smaller. If so, that's rather hard......flames are not exactly easy to control.

Also, how hot would you guys think I need to get this to have it finally break free? If it needs to glow read, I should probably drain it first as I think the oil inside is dissipating the heat away from the case.

Like I said, I can apply whatever force I need as the reverse thread bolt is digging in deep.

Thoughts?

TKH

 

[BG1988]

turn it the other way you are tightening it also use metric ONLY


and NOT a cheat tool like a crescent wrench

 

[Mr T]

turn it the other way you are tightening it also use metric ONLY


and NOT a cheat tool like a crescent wrench

Are you telling me this has reversed threads? What?

 

[Mr T]

Don't think so. I bought a new replacement plug cause I stripped this one badly....I have the new one in my hand. I've confirmed the replacement has normal "Lefty loosey and righty tighty" threads.

 

[wjburken]

Don't think so. I bought a new replacement plug cause I stripped this one badly....I have the new one in my hand. I've confirmed the replacement has normal "Lefty loosey and righty tighty" threads.

The plug has normal threads, so yes, righty tighty/lefty loosey.
I had this same issue before. I took a drill and made a small dimple in the plug, out close to the edge, and then I took a punch and held it at an angle so that it was pointing in the direction the plug needed to turn and hit it with a hammer. That lets you apply an impact type force out close to where the threads are.

 

[drakon543]

go to a metal fab shop and have them weld a real nut on there. specify it has to be welded slowly so they dont burn the diff fluid you do have in there. once there is something with some actual meat on there get yourself a real breaker bar or wrench to match the welded nut and get it off.

 

[swathdiver]

I'd use a two foot long, 1/2 inch drive breaker bar. Put heat on the bolt itself.

 

[Foggy]

You can heat the bolt and the case is fine.. Sometimes just heating where the
threads engage will get them to loosen up after they cool down.
I know it sounds wrong, but just the heat sometimes will break the "seal" that
corrosion or whatever is hanging on to. You are going to have to buy
a new plug anyway.. make sure to use a little teflon paste on the new one.
It will seal it and the teflon will prevent it from seizing. Just go snug

 

[Floep]

Heat the bolt as hot as you dare, let it cool till you can touch it with your bare hands now it will remove easily. The physics is, the bolt expands with heat , has nowhere to go so it stretches the hole ( makes it larger)the when you let it cool it will turn, since it is loose and any goop anyone used to seal it has been burnt out.

 

[swat2380]

I am in the same boat my fill plug will not budge. Used all the normal removal methods with no luck and mine is not rusty. Said screw it and used the gear oil pump I use on my boat and filled it from the drain plug. Been fine ever since

 

[OR VietVet]

Take the left hand thread removal bolt out. Smack the head with a big hammer. The force and vibes from the right amount of force will break loose the threads. I have used heat as well before ad that is my last resort. I normally use what I just described or, like Wade said, a nice dimple from a sharp punch/chisel blade and then keep smacking it in an unthread direction will do it as well and is typically my second attempt choice. If it has threads it will eventually turn out of there. It may bring some of the case threads with it though. Inspect the case threads and clean THOROUGHLY. On a component like that I like to just dab grease on the threads of the new plug and thread in.

 

[mooman]

Air hammer or electric hammer with a point. Dig it into the side closest to the threads and hammer away. I was in your same boat with s stuck drain plug and an Air hammer did the trick. The stock drain plugs are Magnesium and the housing is Aluminium. A very small amount of Anti-seize on the threads will greatly help you down the road. Make sure it is a very light coating on the threads closest to the head and not the bottom.
If you hear front diff noise, it is shot. if you have metal shavings, it is shot.

 

[torch]

Thanks for the thread info, saved me a bunch of headaches! Mine was seized, but I was in no rush, so every day for 3 weeks I sprayed PB Blaster on the plug. Then I used a 6pt socket and a std 1/2 inch ratchet, hit the ratchet handle with my foot, and it loosened right up.

 

[wjburken]

Thanks for the thread info, saved me a bunch of headaches! Mine was seized, but I was in no rush, so every day for 3 weeks I sprayed PB Blaster on the plug. Then I used a 6pt socket and a std 1/2 inch ratchet, hit the ratchet handle with my foot, and it loosened right up.

Glad to hear our experiences were able to help you avoid some frustration. That’s the great thing about this forum.

 

[OR VietVet]

Thanks for the thread info, saved me a bunch of headaches! Mine was seized, but I was in no rush, so every day for 3 weeks I sprayed PB Blaster on the plug. Then I used a 6pt socket and a std 1/2 inch ratchet, hit the ratchet handle with my foot, and it loosened right up.

Great outcome and thanks for posting your first post with a positive result.