Transfer case oil change

[mrmurray]

Greetings, I have a '67 SIIa 88" 2.25L gas, D-suffix transmission. I drained my transfer case to change the pan gasket, and now when I go to fill it back up with oil, I am unable to unscrew the oil fill plug. This is the square plug that takes a 1/2 inch wrench on the back side of the transfer case. Is there another place to add oil to the transfer case? I really dont want to drill out the transfer case oil fill plug, but I cant get it to budge in either direction (using excessive force). Thanks for any input! Mike

[SafeAirOne]

Is the square part where you put the wrench stripped (rounded over)? If not, it'll budge. It's a steel plug in an aluminum case.

Simply use a bigger (longer) wrench or put a pipe on the existing wrench to get sufficient leverage.

Generally speaking, I use a 10" or 12" adjustable wrench; the worst possible tool, but plenty of leverage.

You can always add oil through the topmost inspection plate, but how do you know when to stop, and what about next time?

[Contractor]

What Mark said.

Use a big ass adjustable and it will budge.

If you are doing it on your back in the driveway you are likely struggling with leverage. Take it to your closest shop and ask them nicely to put it up on the lift for you and in less than two minutes you will have it loose.

Buy them a few beers or toss them a few bucks. I have done this before and found that they were more interested in asking questions about the truck than charging me money.

[mrmurray]

I tried the large adjustable, a 1/2 inch wrench with a cheater bar, vice grips, large pipe wrench, etc.. If I put any more pressure on the plug it will round off. I keep soaking it in Kroil waiting for it to loosen up. I know the transfer case is empty because the drain plug comes out, and I can pre-measure the correct amount of oil to add through another opening. I'll try to add through the inspection plate. Thanks!

[stomper]

Put a big arse pipe wrench on it, and order a new one to replace the beat up
One when you are done. I wouldn't leave it there and try to find a work around. You are just putting off the inevitable.

[greenmeanie]

It's a steel plug in an aluminum case.


THIS. I use the BFW method as described by Mark but if your tool ain't big enough to shift it then heat is your friend. Ally expands faster than steel so a little caressing with a blow torch will loosen the plug off where it should shift petty easily.

[o2batsea]

IDK what size the boss on the plug is. If its 1/2 inch across, then you can make an effective tool out of a 1/2 inch drive socket. What I do sometimes is put the square end on the pipe plug, then get something that's hexagonal ( could be some hex bar stock, a standoff, etc) and stick it in the other end. Then using either another socket or the correct wrench I can get gobs of torque on it. I don't recommend something as wobbly as an adjustable wrench, it'll round the thing off and then yr stuck. Thing about this trick is using tools that are larger than the fitting. So if you can find a hexagonal thingy that's like 5/8-3/4 that would be best then you can put a larger tool on it. Hope that makes sense.
For smaller plugs I just use a 3/8 allen wrench in the end of a 1/4 or 3/8 socket.
If the pipe plug is the recessed square kind, then you just use the rachet or bar. They also have hex and torx drive recessed plugs.

[Donnie]

You gotta get that plug out..How do you know that what you drained is the correct amount. Sure you can check the manual for the spec. & fill it from somewhere else.....But using a pipe wrench & an adjustable wrench ???????...No wonder it is rounded off. Not saying that you did it, but there is a correct tool for every job. UNLESS the plug is so screwed up now that a pipe wrench is your only option..... Do like o2batsea said...drive on a 1/2 " socket backwards....then use a 24" pipe wrench & muscle it out. The socket will give you more contact area for the wrench to get a bite. When you replace it with a new one take a look at the plug & see if you can detect a slight taper to the threads....tighten it accordingly...a little never-seize anytime aluminum & steel meet can sometimes be considered.......Donnie

[leafsprung]

You can probably heat the area around the plug to help your cause. A small MAP gas torch should do the trick. The aluminum will expand at a different rate than the plug and ease removal. If you are in a hurry to get moving you can simply add oil through the inspection cover on top of the tcase (through which you can also see the level hole to insure you have the correct amount.) This is actually easier than adding oil through the fill plug anyway . . .