WesD Posted April 10, 2020 Posted April 10, 2020 My NP 231 has an odd drain plug - the 30 MM socket won't fit due to clearance issues with the case, and I can't figure out what type of inner hex/square/torq fitting I can use to get out the middle.
Moose Posted April 10, 2020 Posted April 10, 2020 Looks like a torx in the center. Can't say what size since my drain and fill are both hex plugs
AZJeff Posted April 10, 2020 Posted April 10, 2020 I have never seen an NP231 with a Torx headed plug. It's a Allen type (hex socket) that may be bunged up by previous "repairs". Start by cleaning the crud and corrosion from in the hex hole, and use a pick or the like to clean the corners of the hex. Then you can do a trial and error search for the best SAE or metric allen socket to fit it.
WesD Posted April 10, 2020 Author Posted April 10, 2020 I guarantee it came from the factory like this. It's 8-point something. Nothing has bunged up. I tried to fit a 30MM on it and turn it, but not enough clearance between the housing and bolt to fit the socket correctly (snugly).
Ωhm Posted April 10, 2020 Posted April 10, 2020 Can you ruin a 30mm socket by filing down smooth the opening? Get rid of the part (lip) of the socket opening that doesn't grab. Could give enough bite.
WesD Posted April 10, 2020 Author Posted April 10, 2020 And it's out. 3/8 driver took it out. Fluid looks like a milkshake. Yuck.
JustEmptyEveryPocket Posted April 10, 2020 Posted April 10, 2020 42 minutes ago, WesD said: I guarantee it came from the factory like this Why do you guarantee it? I'm genuinely curious because personally I have not seen this type of plug. Not that I have seen more than 3-4 NP 231s.
WesD Posted April 10, 2020 Author Posted April 10, 2020 15 minutes ago, JustEmptyEveryPocket said: Why do you guarantee it? I'm genuinely curious because personally I have not seen this type of plug. Not that I have seen more than 3-4 NP 231s. Because we have had this jeep since new. Never changed trans, or diff fluids.
WesD Posted April 11, 2020 Author Posted April 11, 2020 New fluid in, transfer case linkage adjusted. It's stuck in 4H. Can't get it to pop back into 2H. Any ideas?
AZJeff Posted April 11, 2020 Posted April 11, 2020 I am glad you got it out., and I will admit, I find that plug quite amazing. I have seen allen plugs, and hex head plugs, but never an eight-pointed plug. (Notice carefully it's NOT a "Torx" shape, which has curved tips of the "points" of the star shape. Maybe one of our "seasoned" Jeepers can comment if this was ever a common type of plug.
AZJeff Posted April 11, 2020 Posted April 11, 2020 23 minutes ago, WesD said: New fluid in, transfer case linkage adjusted. It's stuck in 4H. Can't get it to pop back into 2H. Any ideas? Can you jack it up so all the wheels can turn by hand, and then have some helpers turn those while you fiddle with the linkage?
velco Posted April 11, 2020 Posted April 11, 2020 The 231 drain plug is 12mm/12point. This is according to my transfer case.
JustEmptyEveryPocket Posted April 11, 2020 Posted April 11, 2020 22 hours ago, WesD said: Because we have had this jeep since new. Never changed trans, or diff fluids. That seems like a good reason to think its factory. Learned something new today.
cruiser54 Posted April 11, 2020 Posted April 11, 2020 Here's how the factory suggests you shift the transfer case and I've been doing this since these things were new and I worked at the dealership. Quoted from the owner's manual. The suggestions in CAPS are mine. "To engage, shift the transfer case lever from 2H to 4H while the vehicle is moving at any legal speed". I LET OFF THE GAS, THROW THE LEVER, TAP THE GAS AND LET OFF. 4L position: " To engage, slow the vehicle to 2-3 MPH , shift the transmission to Neutral, then shift the transfer lever to the right and pull firmly rearward to 4L". TO SHIFT OUT OF 4L, SHIFT THE TRANSMISSION INTO NEUTRAL WITH THE VEHICLE STOPPED, SHIFT THE TRANSFER CASE LEVER TO 2H, THEN THE TRANS TO D IF YOU HAVE AN AUTOMATIC, OR INTO FIRST GEAR WITH A MANUAL, AND CONTINUE ON. Revised 11/20/2014
WesD Posted April 12, 2020 Author Posted April 12, 2020 I tried exactly that. Numerous times. I've tried everything thus far. Going to do one more fluid flush and see if that helps loosen it up a bit. Shifts between 4H, N, and 4L just fine.
Warren Mohler Posted April 12, 2020 Posted April 12, 2020 10 hours ago, WesD said: New fluid in, transfer case linkage adjusted. It's stuck in 4H. Can't get it to pop back into 2H. Any ideas? Raise off ground and try, happens a lot if tires are worn different
fiatslug87 Posted April 12, 2020 Posted April 12, 2020 On April 10, 2020 at 3:41 PM, WesD said: ...we have had this jeep since new. You should post here, assuming you're talking about an MJ.
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