Removing rear diff. fill plug.. any ideas?

[WXman]

My rear differential fill plug is frozen in place. I haven't even attempted the drain plug yet. I used a 24mm socket with 1/2" drive ratchet and it started to round off the bolt. So then I tried a 15/16" box end wrench. No luck. Tried a chisel and hammer. No luck.

I have a new drain and fill plug at the dealership waiting on me to pick them up. Any ideas on how to get the existing fill plug out???

 

[KidVermicious]

You absolutely need a 6 point socket, for sure. Then PB Blast twice a day for two or three days should help. If that doesn't do the trick, give it some heat from a propane torch, LOTS of heat. If it still won't budge after a couple heat cycles, buy a disposable 15/16th six point socket and hammer it on there nice and tight. If it still rounds the corners and won't budge, your last resort is to weld a harder nut to the face of the fill plug and turn it with that.

Obviously you'll want to order new fill and drain plug bolts (I like the hex head ones), and this time don't spare the anti-seize. Good luck!

 

[WXman]

Nevermind.. I just searched Google and found lots of threads on this topic. Should have done that first. My bad.

 

[Mtn.Runner]

Seafoam deep creep and a pair of channel locks or vice grips.

 

[WXman]

You absolutely need a 6 point socket, for sure. Then PB Blast twice a day for two or three days should help. If that doesn't do the trick, give it some heat from a propane torch, LOTS of heat. If it still won't budge after a couple heat cycles, buy a disposable 15/16th six point socket and hammer it on there nice and tight. If it still rounds the corners and won't budge, your last resort is to weld a harder nut to the face of the fill plug and turn it with that.

Obviously you'll want to order new fill and drain plug bolts (I like the hex head ones), and this time don't spare the anti-seize. Good luck!

Thanks!

 

[Snesley Wipes]

My rear differential fill plug is frozen in place. I haven't even attempted the drain plug yet. I used a 24mm socket with 1/2" drive ratchet and it started to round off the bolt. So then I tried a 15/16" box end wrench. No luck. Tried a chisel and hammer. No luck.

I have a new drain and fill plug at the dealership waiting on me to pick them up. Any ideas on how to get the existing fill plug out???

I have heard good things about PB Blaster for unseizing bolts...havent used it yet but may be worth a try.

 

[woodro]

Get a impact that you hit with a hammer and it turns ( not sure the name of tool ) . Couldn't get mine off , hit one of these and it came off in 4 shots .

 

[YotaDriver]

My rear differential fill plug is frozen in place. I haven't even attempted the drain plug yet. I used a 24mm socket with 1/2" drive ratchet and it started to round off the bolt. So then I tried a 15/16" box end wrench. No luck. Tried a chisel and hammer. No luck.

I have a new drain and fill plug at the dealership waiting on me to pick them up. Any ideas on how to get the existing fill plug out???

You can also try using a 50/50 mix of automatic transmission fluid and acetone. It's supposed to be orders of magnitude better than PB Blaster or other comparable products.

 

[KidVermicious]

You can also try using a 50/50 mix of automatic transmission fluid and acetone. It's supposed to be orders of magnitude better than PB Blaster or other comparable products.

I actually tested a 50/50 ATF and acetone mix against PB Blast against my lugnuts, the '85 was an ocean truck and had been sitting for years and they were frozen so tight I was twisting studs off. So I soaked one set in PB Blast for two days, they came free on the second day. I hit the other side with the 50/50 twice a day for four days, then gave up and used PB Blast, they came free on the 5th day. That ATF/acetone mix doesn't work.

PB Blast is the bomb, you just need to give it time to cook.

 

[WXman]

Great ideas guys. I'll give it another whirl tonight when I'm home from work.

 

[bensanders]

All good suggestions. I tried all of them on mine back when I first got the vehicle. None of them worked though, sometimes that just happens.


I had my mechanic weld on a socket and remove it.

 

[WXman]

Success! arty:


Used a large air compressor powering an air chisel and shocked the fill plug loose. Then used a heavy duty air impact gun to free the drain plug. Replaced both with new plugs and new crush washers, torqued carefully by hand. The previous owner or whoever worked on this thing before must have put these in with an impact gun...it was ridiculous.

Put 3 quarts into the diff and it still didn't run out of the fill hole. These axles are hard core. You'd see something like this on a 2500 series pickup.

 

[Jeff T]

Congrats!!!

Did you fill it with synthetic??

 

[BlackWorksInc]

I actually tested a 50/50 ATF and acetone mix against PB Blast against my lugnuts, the '85 was an ocean truck and had been sitting for years and they were frozen so tight I was twisting studs off. So I soaked one set in PB Blast for two days, they came free on the second day. I hit the other side with the 50/50 twice a day for four days, then gave up and used PB Blast, they came free on the 5th day. That ATF/acetone mix doesn't work.

PB Blast is the bomb, you just need to give it time to cook.

Interesting, a member had posted a link to a military study (IIRC) that talked about the 50/50 being the best to use. I had been wondering how well it works.

 

[KidVermicious]

Was that a military test? I thought it was a machine shop that did that.

In any case, I wasn't impressed with their test, it was sloppy. They had no control, no way to know that they were subjecting their test nuts to the same standard of abuse, etc. I'd love to see a proper lab run some rigorous tests and see what they get.

 

[4RunnerFan]

Success! arty:


Used a large air compressor powering an air chisel and shocked the fill plug loose. Then used a heavy duty air impact gun to free the drain plug. Replaced both with new plugs and new crush washers, torqued carefully by hand. The previous owner or whoever worked on this thing before must have put these in with an impact gun...it was ridiculous.

Another tip is to put Anti-Seize on either the back of the bolt head or on the face of the differential around the hole and then torque no more than spec. Will come off real easy next time.