93 Fzj80 Seized rear diff filler/drain plugs !!

Joined
Mar 8, 2020
Messages
9
Location
adelaide australia
Gday all,

I'm doing my rear bearings and brakes.
Currently , Im being stopped at the starting line by seized filler/drain plugs on the diff housing.
What stupid :censor::censor: designed these things !!!
The drain plug is countersunk meaning a socket or big ringy is your only option and the filler plug (which I feel that I have to prove can be removed first , before I start draining oil) has a tiny 4 mm high profile and seems very prone to tool slippage and rounding off.
So far I'm using a 24mm (6 point) impact socket and a breaker bar with a 1m piece of pipe (as a lever /extension) on the filler plug.
It just won't let go, and the socket has just slipped, rounding the nut slightly....great!
I've tried heating it with a torch ... tapping the :censor: out of it with a mash hammer.....the :censor::censor::mad: just won't move.
I'll hazard a guess that someone B4 me, couldn't be bothered getting new crush washers and just did the plugs up super tight . Probably with a rattle gun !!
I don't want to put the car back together and drive it down to the shop who'll charge me $1000000000 for walking through the door and I'd prefer not to fork out 250 bucks for my own impact driver ( rattle gun ) .
I swear ..these pieces of :censor: are going to be replaced with something more practical once I get them out!!
Has anyone had any success removing these plugs when they've been this stubborn? I'd Appreciate any tips/tricks/advice.

( please excuse my :censor: frustration :banghead::banghead::banghead::singing: )
 
Joined
Jan 7, 2005
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6,443
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The Greatland
 
 
 
Stop anguishing about it and use an impact wrench. It largely eliminates the twist that causes you to slip off the head of the plug. It is the most effective way and possibly the only way to get an overly tight fill/drain plug out.

Once the head is truely F'd up, you may have to weld a large nut to the face of the plug to get a decent grip on it.

After you remove them, replace them the the later style OEM Allen head plugs.

Mark...
 
Joined
Nov 9, 2012
Messages
9,215
Location
Olathe, KS, USA
 
Also, to help with the slip:
1) Use a 15/16" hex socket. It is a fraction tighter than the 24 mm socket.

2) Grind the face of the socket to eliminate the tapered portion interior so it gets a better bite on the full depth of the head of the plug.

3) Try to tighten the plug first. Frequently this will break the friction and then it will come loose.


4) Hit the plug straight on with a hammer and hit it hard enough to get it's attention without being enough to dent the housing. Make sure to hit it square.

5) Use a handheld propane or mapp gas torch and heat the plug for a couple minutes then cool it with spray on PB Blaster. Do this twice, then let it cool and restart on this list. This should break it loose.

If not, do the weld a big nut on it part. The heat from welding will usually break it loose.
 
Joined
Mar 8, 2020
Messages
9
Location
adelaide australia
Stop anguishing about it and use an impact wrench. It largely eliminates the twist that causes you to slip off the head of the plug. It is the most effective way and possibly the only way to get an overly tight fill/drain plug out.

Once the head is truely F'd up, you may have to weld a large nut to the face of the plug to get a decent grip on it.

After you remove them, replace them the the later style OEM Allen head plugs.

Mark...
Hmmm...Unfortunately, my anguish is not without cause. My dollars are currently having to stretch further thanks to Covid-19.
I'll have to select one of the kids, and sell them for scientific experiments to afford a rattle gun, :) ...but hey ...thank you Mark for the benefit of your opinion.
I'll take a fresh look at it in the morning. 👍
 
Joined
Mar 8, 2020
Messages
9
Location
adelaide australia
Also, to help with the slip:
1) Use a 15/16" hex socket. It is a fraction tighter than the 24 mm socket.

2) Grind the face of the socket to eliminate the tapered portion interior so it gets a better bite on the full depth of the head of the plug.

3) Try to tighten the plug first. Frequently this will break the friction and then it will come loose.


4) Hit the plug straight on with a hammer and hit it hard enough to get it's attention without being enough to dent the housing. Make sure to hit it square.

5) Use a handheld propane or mapp gas torch and heat the plug for a couple minutes then cool it with spray on PB Blaster. Do this twice, then let it cool and restart on this list. This should break it loose.

If not, do the weld a big nut on it part. The heat from welding will usually break it loose.
Hey mate!

Thanks for the reply

1) ....Tried this with a non hex version... Still felt like it was going to slip, so I stopped. I'm considering buying a Hex version as it could be a cheap solution
2)... Also considering this as I've just read it in another thread ...seems like a good idea.
3)....Tried that ...won't budge in either direction.
4).... Sadly, not a lot of room to swing ...I have an LPG tank in the way, but I recon I've given it a few good Knocks . More to come !
5)... Tried heat , but not your exact process ...I'll focus on that tomorrow to start with.

Thank you very much for your ideas. Appreciated.
 
Joined
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New Jersey
 
 
 
Joined
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adelaide australia
Thanks for that :)
 

BlueCruiser84

SILVER Star
Joined
Nov 1, 2004
Messages
3,189
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Staunton, VA
 
 
 
If the 15/16 socket doesn’t work I second or third the “weld a nut to it”. Drive somewhere have them do it if you don’t have a welder. The heat from welding will break it free and the nut will give you something to grab.
 
Joined
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Messages
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adelaide australia
And the winner is BILT4ME!!!! with his extreme heat and cool method.
As I said, I had tried heat , but not enough . This morning I grabbed a can of freeze-It for $20
I started by heating the bolt up super hot with a propane torch . This alone wasn't enough to move it .
Next I heated the bolt and then froze it instantly. That also failed.
Final successful method was to heat the casing around the bolt ( carefully ) then apply freeze to the bolt only ...assuming that the "separate" surfaces being forced to different extremes of temperature might do ...something .
All this finally did the trick . 👍
( I also had to remove the handbrake cable and drop the stabiliser bar so I could get a pipe wrench onto it. The Nut was F'ed by this stage ...lucky .)


filler plug.jpg


Thanks to ALL for your suggestions and wisdom . Much appreciated. :) :) :)

Now for the drain plug !!!:bang:
 

flintknapper

SILVER Star
Joined
May 22, 2004
Messages
7,636
Location
Deep East Texas
 
 
 
And the winner is BILT4ME!!!! with his extreme heat and cool method.
As I said, I had tried heat , but not enough . This morning I grabbed a can of freeze-It for $20
I started by heating the bolt up super hot with a propane torch . This alone wasn't enough to move it .
Next I heated the bolt and then froze it instantly. That also failed.
Final successful method was to heat the casing around the bolt ( carefully ) then apply freeze to the bolt only ...assuming that the "separate" surfaces being forced to different extremes of temperature might do ...something .
All this finally did the trick . 👍
( I also had to remove the handbrake cable and drop the stabiliser bar so I could get a pipe wrench onto it. The Nut was F'ed by this stage ...lucky .)


View attachment 2330007

Thanks to ALL for your suggestions and wisdom . Much appreciated. :) :) :)

Now for the drain plug !!!:bang:

Yeah...that plug was knackered for sure.
 
Joined
Mar 8, 2020
Messages
9
Location
adelaide australia
View attachment 2331108
This would be another option. Glad it worked out for you.
Hey Surg....
I Took a closer look at that picture you posted ...the socket in your hand. It wasn't what i first thought.
I took a look at the manufacturers site and yeah they look good!!! ...Never seen/heard of them before. I might see if i can my hands on a few.
I gather you are endorsing them ...they're good yeah ?
 

surg0107

GOLD Star
Joined
Apr 27, 2017
Messages
83
Location
Middle TN
It worked great for me. I bought it off Amazon. I tried the shaved down socket - no luck. This was before I had a decent heat source/torch or a welder. I was not interested in doing the “drive of shame” to have a shop weld up something to remove it. Replaced them with the hex head drain plugs from Wit’s End @NLXTACY.
 
Joined
Aug 9, 2003
Messages
9,014
 
 
 
So, I helped my brother in law get his plugs out of a shop-maintained 80 where they apparently used a rattle gun to install them. The technique that worked was to find a way to place force keeping the socket on. For the drains, use a floor jack to push it up hard so it won't slip off. For the fills, I used a pipe and a wedge to apply enormous pressure to keep the socket pinned on there. The fill was so tight, I had to use the floor jack to apply force on the end of the breaker bar. When it let loose, it made a horrible bang and I thought the plug snapped or the threads in the axle housing let go. But all was well. Last week, I did my diffs and they came off with an ordinary 3/8 ratchet wrench with a yawn. Yes, I put them on 160,000 miles ago. The pure and unmitigated joy of doing your own work right there.
 
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