Rear Diff Fill Plug - Welded on?!? Help!

He's not saying use a manual impact driver, but rather literally hit the head of the bolt with a hammer.

I've done it on some stubborn head bolts, helps loosen them up, works wonders.

 

Just pull an axle and tilt it sideways

 

Fill plug is hollow on these. Since we're talking about the rear diff and not something more sensitive, I'd get a good 3/8" HSS bit, and drill out the center of the plug. Then I'd toss in a good 3/8" nipple extractor, grab it with a 24" pipe wrench (for extra leverage, you may want to try an offset pipe wrench) and break the sucker loose.

Added benefit is that if that method fails, you've hollowed out the plug along it's full depth. Put a chisel perpendicular to the new hole, and beat on it with a hammer. The idea is to collapse the plug. If you do it right, it won't hurt the threads in the diff. housing. If the walls are still too thick to collapse, re-drill with a 1/2" bit and try again.

It'll come out. If 1/2" won't do it, go to 5/8". I wouldn't go bigger than 5/8".

I don't know if the threads in the housing are IPT or not. If they are, and if you can find one (goddamn metric system!), I'd replace that fill plug with a brass plug. You can get them in square drive (internal) like the front diff plug, but square instead of hex. Brass is easier to de-mangle next time around, and it won't rust *to* the steel (it will corrode, of course).

 

This^ Also most of the time if you apply a lil heat it will make it easier for removal, though I'm sure you're past that point now.

 

Before removing it get a new one to replace it and have on hand.
I had a similar problem took it to a shop and the put an impact wrench on it to get it off.

 

I've removed many a stubborn bolt with a little heat. In fact everyone I could not get out with other means finally yielded when the torch was applied. Welding on a nut is another good idea if you can't get hold of it.

On a side note ,when get to replacing the plug, use pipe dope on the threads and you'll never have this problem again.

 

This....heat may be the key. Also, as last ditch effort vise grips and heat it a bit with a torch.

 

So I went to see a welder and he welded a bolt on to try it, sheared the head clean off. Then he welded a nut to the remaining bolt threads, same result!!

He gave up and didn't even charge me for the work.

Looks like my only two options left are to drill it out or fill through the breather.

Thanks everyone for the suggestions, very much appreciated!

Al

 

Take it to a good mechanic.

 

eff it.

Drill the whole thing out and re-tap for a larger bolt.

 

If it were mine I would weld another bolt on it, then let it cool completely and use a torch to heat only the TC. Try to heat the case around the bolt and it should expand slightly. Then it should come off easy.

Drilling it might be a hassle, you'll have to flush it really, really well after to make sure there is no metal in your gears.

 

subbed to see where this ends up

 

Wow, I though mine was bad. Sub'd for outcome, make sure you anti-seize the new bolt if you ever get the old one out.

 

If you're good with a drill, you might be able to coax the bolt into collapsing before you actually drill the threads out, and then you could just scrape the pieces out of the threads, clean up the threads and use a factory bolt.

 

this is ugly!!

did you allow everything to cool before you yanked on it with a wrench..after welding?

i wonder if the plug expanded and got tighter from the heat.

too late, but i would have banked on a big bolt out. they make lug nut sized ones now.

 

In fairness I don't think it was fully cooled before he tried the wrench on it. Poured a bit of cold water over it until it was cool to the touch.

Up close its hard to tell where the bolt head ends and the diff begins.

Not many people seem keen on filling through the breather, but I honestly don't think this bolt is going to give and drilling it may put too many shavings in the housing. This is beyond frustrating!!

 

Sounds straight forward but could you please elaborate on the process?

 

You pull the 3rd, write up in stickies on top of this forum, then you could either drill it out or seal it up and then drill a new hole above and weld in a bung for an oversized fill/inspection port. Like ruff stuff does with their housings. Then you can clean all the crap out of the housing. Its not too bad...


Either way you should probably pull the 3rd at this point.

 

http://www.trail-gear.com/fill-inspection-cap

 

Reviving an old thread but some were interested in the outcome.

Cost me 30mins of Toyota Dealer labour. Worked out to $40 and in the end I just had them drain and fill the diff, but at least I'll be able to do it myself the next time.

Thanks again to all who posted their suggestions. No thanks to person who did the last fluid change!

Cheers,
Al