Diff fill plug .....

[langleylad]

Time to change diff oil in the S10 but that fill plug is frozen in the case . Any tips on how to get that sucker out . Thanks

[oldsman71]

did you strip the square hole out or it just wont break loose?

[langleylad]

just wont break loose !

[oldsman71]

a good 1/2 to 3/8 adapter on a 1/2 breakover bar make sure the square hole is cleaned out good and you are getting a good bite inside
the plug, if you dont have a breaker bar you can use a cheater bar on a 3/8 rachet it works best without an extention, a little pb blaster or kroil around the edge of the plug for a couple of days might help too, but clean around the plug really good so it can soak in

[OldMachinist]

Don't know how well it will work with the lube in the diff but heat just the plug with a large tip on your torch. This will swell the plug in the housing. Then apply parrafin to the threads while still hot which will draw the wax into the threads and act as lubrication. Let cool completely so plug shrinks to original size and plug should come out easily.

[68scott385]

I feel your pain. Good Luck!

New Years, no, I don't have a life, I decided to change the rear fluid on my 88 Caprice wagon. The plug was stuck as yours is. I tried all the chemicals known to man with no luck. I wound up drilling the plug.

My intention was to go as big as the drill size needed for 1/2"npt but my larger bits were not sharp enough at the time. I managed to drill large enough to tap the plug with a 5/8 tap and got the plug to start moving in its own threads but not enough to come out. So I cross-threaded the tap in the threads it just made and was able to screw the cap and tap into the differential housing, not my first choice of direction but the only one that worked. There was enough room to get both out of the housing with minor turning of the pinion and ring set.

I sincerely hope you don't have to go the same route I did.

[squirrel]

I'd try the torch trick, before the drill

[68scott385]

Yeah, if you own a torch that's the way to go...buying a torch is higher on my to-do list now.

[squirrel]

It is a big expense....but one of those things you can't live without if you have one.

[68scott385]

I like to think of expense in a relative manor. A torch won't be any more expensive than the mig welder or metal bandsaw I have. At some point in this hobby/career you have all the small tools (sockets, ratchets, pliers, wrenches, screwdrivers, etc.) you can store. Then it's on to the higher dollar stuff; welders, torches, battery chargers, presses, bench grinders, etc. Or simply stated, the longer you're in it, the more money the tools cost. I just haven't had a big need for a torch set so I aquired other stuff first.

[CDMBill]

Borrow the torch from a buddy and them let him use the lift you are eventually going to buy anyway.

[langleylad]

Thanks for your help Oldsman & Oldmachinist . Job done .

[squirrel]

Did you get it off without the use of heat?

[Buckeye]

Let James drive it on power tour and it will fall out!

[langleylad]

Heat , wax , and swearing !