I like the idea of filing down the bolt to the next smallest size if you can't weld a nut on it.

 

Yeah, I did this on mine. With a dremel it was pretty easy and worked like a charm.

 

I know this thread is old but this happened to me a while ago. Heres what I did.

Take some vice grips, put them on the bolt, then take a pipe wrench (monkey wrench) and tighten the vice grips down with them. I then took a hammer and tapped the vice grips till it was loose. Worked prefectly.

 

I changed all of my drivetrain fluids again last week (front diff, transfer case, rear diff) and found that the front diff drain plug (10mm) was a bit worn out. Luckily I was able to crack it loose, but I thought I may not be as lucky the next time. So I bead-blasted the plug/bolt, cut the head off of a grade-8 10mm socket-head bolt I had in the shop, and cleanly welded it on the plug/bolt. Problem solved, and a damn fine weld job to boot.

I always use anti-seize on these bolts, but for some reason the front diff drain plug has always been diffcult to remove.

I've drained & re-filled these fluids every 40-50k miles since new.


Andreas

 

Tip for the front differential drain and fill plugs w/ that style of plug. Smack the plug with a hammer a few times, directly on the head and flat. It doesn't damage anything and sometimes you don't even need to break it loose after that. I service GX470's everyday and their diff is the same. My tools and my knucles thank me for it!

 

if you have it you could fill through the abs sensor hole on top of the diff, its nice and big alot bigger than the breather

 

Thanks folks for all the help! I ended up using a propane torch and a good pair of vise grips that where rounded instead of squared. That way, I could grip more of the plug.

I used my torch and seafoam, heat-spray-heat, then put the vise grips on it as tightly as I could and it FINALLY cracked loose.

I replaced both drain and fill plugs.

I actually had to back the truck up on ramps so I had more leverage to break the bolt loose.

I never thought to use a hammer on the plug...interesting.

 

snag one at a pick and pull

 

would you consider this safe? I dont know about this, but my gut feeling is to not let an open flame near a fuel tank.

I liked the tapping on the head of a bolt with a hammer idea. I havent tried this, but will soon.

 

Its fine man, I used propaine. It doesn't get that hot, and if you know how to use a torch its no big deal.

I bought a torch with flame control so I can let as much as I want when I want it. Besides your going to be working close to that rear diff, no heat will even be near the gas tank or lines...

I wouldn't of done it if it was dangerous.

 

I know this is an old thread, but it is a common problem so I thought I'd share my experience. I had same problem...Stuck/stripped front differential fill plug. I used a Propane torch on the bolt and around the bolt for approx 2 minutes then used a breaker bar with a 24mm 6 sided socket and voila! Came right off. Heat works miracles. My plug was pretty rounded off from trying pb blaster and a pneumatic impact wrench first. Luckily I just had enough of a bite left on it that it broke free finally with heat.

 

On my '98 ltd, the front drain plug has a 12mm allen socket, and a 24in breaker was only starting to strip that out. There is no way to put vice grips on that flush head. I used some propane heat, and a cold chisel around the small arc of exposed plug rim, and it was STILL not budging. Using the breaker, I found I was able to TIGHTEN the plug slightly, and after that it loosened without abnormal force. The replacement plug from the dealer has a wimpy 10mm allen socket, when it really needs to have a larger allen or even better a protruding hex head. I ended up reusing my slightly battered plug instead of risking a future disaster. The new plug needs a welder mod before it can be trusted.

 

You can get Hex Head Plugs that fit

 

Are you sure, I thought due to the recessed location and size/thread the front drain had no alternative replacement.