DIY rear diff fill plug

[arm1984]

I have rounded off my fill plug for my rear diff. It has obviously never been removed and it probably never going to come out now. After reading on here I have a number of options.
1. Drill the plug try use an easy out extractor and hopefully get it out that way.
2. Buy a new diff cover with fill plug.
3. Fill via the ABS sensor.

Now neither of these are appealing as if 1. doesn't work I'll have swarf in the diff and have to drain with no way of filling 2. seems quite expensive. 3. Everything seems fragile and temperamental. If I do this I know it will break and never work again.

Option 4. Remove diff cover. Drill suitable size hole for 15mm female coupler plumbing fitting, fit and seal with sealant and use 15mm end cap to finish off. Question, is there enough clearance inside the diff to do this? If so cost will be about £3.

Any one done this? Any one got any other ideas?

 

[janolsson]

Have you got the facility to weld a nut onto it? This also has the benefit of putting a load of heat in it. If you do it yourself you could even spray penetrant on it whilst it is still hot.
Remind me, is the fill plug a recessed allen key or extended hex. If extended hex (ie like a bolt head you could hammer on a slightly smaller imperial socket. If recessed allen then you could hammer in a spline bit. either way hit it with a lot of heat and penetrant first.

Oh and when I say penetrant, I mean PENETRANT not that wd40 fish oil stuff ;-}

 

[arm1984]

It's a 3/8 socket hole. No ability to weld. I'll keep trying with the heat maybe I didn't use enough. Not sure there is enough of the socket left now though.
Hammering anything in or on is difficult as I don't have access to a vehicle lift and due to it's position makes it very difficult to get a good hit.
I'll take a look at the abs sensor again tomorrow as this is probably the easiest route to go but like I said a pain if I break it.
Thanks for your input.

 

[janolsson]

You could insert a short bolt into the recess and then weld that in or fill the recess with weld then weld a nut onto that.

Another thing to try, if you can get the angle, is a blunt chisel to shock turn it to start it off

 

[arm1984]

I've managed to get the fill plug out. Luckily there was enough socket hole left. I did nothing different today than before, it just worked today. That fact alone makes it even more frustrating. Anyway managed it in the end without drilling, welding etc.
Also managed the fuel filter too. Surprising amount of petrol in the filter when its running over you.
Thanks for suggestions/help.

 

[BKennedy]

When you get a new fill plug, get an aftermarket hex head plug instead of the 3/8" socket. I ruined my stock one years ago and the hex head has held up.

 

[arm1984]

Ok thanks for the tip.