The refil bolt on my diff is being an utter %*&! and doesn't want to come out. Is this usual or am I unlucky?
I've given the bolt a thorough dowsing with WD40 with no joy.

What next?

I don't think it's that unusual. On mine I had to use a long bar and a big hammer. WD40 isn't a very good penetrating oil- it's not terrible but it's not the best. I'd use some proper penetrating oil and give it a goodly time to work. If that doesn't work get out the blowtorch and heat it up a few times to break the stiction.

I'd give it a shout with some PlusGas to see if that helps - bit more hardcore than WD40.

Failing that, I'd consider putting an impact driver on it, and give it a thump. It's a big enough bolt, so that might jolt it free.

As a last resort I'd maybe try an impact gun if you have one....

Mine came out with a big hammer and a chisel, and plus gas.

Then fitted a replacement drain plug

Mine was a total swine to get out too, i also resortd to hammer and cold chisel.

They always were a bugger to get out on Sierras. Quite common to round out the allen key trying as well. Heat and shock (hammer) is the best answer.

Thanks for the replies guys. Not too keen in applying a naked flame to it because of the close proximity of the fuel tank. I'll try the plus gas and see how I get on from there.

Done several - all were stuck - all shifted very quickly with a couple of smacks from the hammer and cold chisel

have always used some heat, not direct flame , but a heat gun , might take a bit of time but generally works.

That would never have been a problem with the cars of the 50's.
That plug was taken out every 5000 miles to check how much lube had been lost since the last inspection.
See modern cars are better, we're just a little less thorough.

I ended up welding a normal hex bolt head onto the original bolt head after I rounded it out. The heat from the welding, and the better grip I could get on a bolt head managed to break it free.

i welded a nut on mine too... came out easy then

I cut a slot across the plug with a cutting disc and used a piece of flat bar to remove the plug +the heat of cutting the slot helped to release it

Jacko

Got the barsteward out at last

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