I have not been able to remove the fill plug in my NP231 t/case because I guess it hadn't been checked recently when I bought it. I got a new 10mm allen wrench but it still won't budge. I went so far as to try to force it and the wrench now will turn inside of the opening. Don't want to take it somewhere and pay though the nose to get it drilled or torched out. Anybody have this problem and figure out a shortcut? Could I just drill out the center and tap a new thread in that hole? I have owned it a little over a year and haven't been able to check the fluid level. It doesn't leak or make any noise so I assume it has enough fluid up til now.

 

Just some ideas for you. I don't have to deal the allen head plugs but have helped a couple of friends out with similar problems as you're having.

On one, we found a bolt that fit inside the stripped out plug and welded it in, then used a regular wrench on the welded bolt.

My other buddy didn't have a welder, so we tried a few different things, btu what ended up working for him was taking a torx bit... I don't recall what size, but it was slightly larger than the hole in the rounded out plug... and a BFH and we pounded that torx bit in to the hole in the plug. Then we used a torth (all he had was propane) to heat the heck on the aluminum tcase around the fill plug, and with enough heat, it came right out.

There might be better solutions, but those two things I know, first hand, will work... and would probably be preferred to drilling and getting metal shavings in your tcase.

 

My brother had a similar problem and was eventually able to remove a stubborn plug using this stuff called "Freeze-Off". Basically, you spray it directly on the part you want to remove. The stuff in the can makes it extremely cold causing it to shrink. This loosens it up and you can then remove it.

I would have been skeptical, but my brother told me it really worked. For $6.00 it can't hurt to give it a try:

http://www.oreillyauto.com/site/c/de...ord=freeze+off

 

Drilling I will say no, metal shavings will get inside the t-case for sure

In the past I have used a large bolt, that I can grind the thread to fit tighly into the stripped surface, cut the lenght of the bolt so it will go almost all the way in, leaving part of the bolt out to be welded to the stuborn plug, weld that really good, let it cool for a couple of minutes, and use the Hex head of the recently welded bolt to use a regular wrench, or a ratchet.

The combination of the heat caused by the welding, and then having a good bolt to apply force will do the trick.

Hope it helps

 

Based on what you've written I'm guessing you've already drained it. Always remove fill plugs first!

I like the idea of welding in a standard bolt. If thats not an option for you I'd go for a propane torch to heat it and it should come right off.

 

When you get the plugs out, go back in with these NAPA plugs:

 

I haven't been here, but have dealt with plenty of stubborn stuff. I like that idea. The pounding may well help loosen it. Seems worth a try. I'd just use a regular hammer or ball -pien, not a single jack or sledge!

 

Thanks for all those great suggestions! Fortunately, I have not drained the t/case yet. I was only trying to check the fluid level. I will start with heating it (propane) and using the torx bit first. I don't have access to a welder or anyone who has one so I may have to find a shop that won't rape me to weld a bolt to it if the other way doesn't work. I guess that having shavings in the t/case doesn't worry me too much on a unit that has 266xxx showing on the odometer. I will definitely get a pair of those NAPA plugs to replace the factory parts.