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Danwa
August 25th, 2009, 12:35
Does anyone know what the small brass plug at the bottom of the np242 transfer case is? It appears to be leaking. This is on an 88 cherokee. Thanks

Hudson Bend
August 26th, 2009, 11:06
A drain plug? Do I win?

1990JEEPXJ
August 26th, 2009, 11:10
mine leaks there too. could be a drain plug, maybe an access/inspection hole as well. but i dont know for sure.

kastein
August 26th, 2009, 12:31
I'd have to guess a drain plug, though I don't believe I've ever seen a brass drain plug.

Is it the same shape and size as the fill plug further up the case? My parts catalog shows two #4210616 being required for the NP242 transfer case, one at the bottom of the rear casting and the other further up the rear casting. If in doubt, don't remove it. This won't happen on a 242, but I know of some manual transmission models on other vehicles that appear to have two fill plugs - there are two bolts that look exactly the same from the outside. However, if you remove the wrong one, it actually is the fitting that holds the end of a shaft in place - removing it allows the shaft and portions of the shifter linkages to fall down inside the case! This resulted in a garage I worked at paying to rent a car for one of our customers and repairing his transmission free of charge after one of the less-than-intelligent techs pulled the wrong bolt while doing a fluid change.

KaiserMan
August 26th, 2009, 15:33
Probably an inspection plug to check the slack in the chain. Jeep BW QT's had one for that purpose.

mfascuba
August 26th, 2009, 20:18
Got a picture? The only two plugs to mess with on an NP242 are on the back of the unit, one for draining the other for filling. I think the one you're talking about is a pivot point for internals - don't take it out unless you're taking the whole transfer case apart to rebuild it.

My two cents...

Mark

fyrfytr1717
August 26th, 2009, 20:34
NP242 fill and drain plugs (outside view)

http://i511.photobucket.com/albums/s359/fyrfytr1717/Tranfer%20Case%20Lift/TCLift08.jpg?t=1251339809

NP242 (inside view)

http://i511.photobucket.com/albums/s359/fyrfytr1717/Tranfer%20Case%20Lift/TCLift09.jpg?t=1251339840

That's all there is, at least on my '99 anyways. Incidentally, when draining your TC, remove the fill plug first, then the drain plug. This will allow air into the case while the fluid is draining and prevent it from "glugging" fluid all over the place.

1990JEEPXJ
August 26th, 2009, 20:41
i will snap a pic of it later and show you what he means.

Danwa
August 27th, 2009, 06:18
Yes Kastein and others,

I was worried about internals issues. I think I read somewhere that there was a detented shaft and spring connected to that plug. Anyhow, again, it appears to be brass right at the bottom of the case. I do know where the drain and fill plugs are, I just wanted to get this leak fixed without having to take apart the case. Oh well, maybe it's time. I have 251,000 miles on it now.

kastein
August 27th, 2009, 08:38
Incidentally, when draining your TC, remove the fill plug first, then the drain plug. This will allow air into the case while the fluid is draining and prevent it from "glugging" fluid all over the place.
It also prevents you from being up a creek without a paddle should your fill plug be frozen... unlikely to happen with brass in an aluminum block, but still not something I like to take my chances with. Incidentally this is also why you should *always* remove the engine oil fill cap before draining the oil.

fyrfytr1717
August 27th, 2009, 21:47
Anyhow, again, it appears to be brass right at the bottom of the case. I do know where the drain and fill plugs are, I just wanted to get this leak fixed without having to take apart the case.


I'm curious now... is it on the front half of the case? 54 in this picture?

http://jeep.avtograd.ru/xfer/encyclopedia/NP242/images/NP242_parts.gif

kastein
August 27th, 2009, 22:09
I think he's talking about #20 in that picture, but not sure...

1990JEEPXJ
August 27th, 2009, 22:44
not #20. its not the conventional fill and drain plugs.

mfascuba
August 27th, 2009, 23:59
# 54 is the brass plug - has to do with the shifting mechanism.

Mark

alfman
August 29th, 2009, 09:47
#54 should be the sift detent ball, spring & plug. If it is leaking you can back it out a turn or two, clean it up with brake cleaner, squirt a little silicone sealer in between the head & the case & tighten it up. Should stop the leak.

Danwa
August 29th, 2009, 15:09
Yes, that's the one, #54. I will try backing out and doing the silicone thing. Good idea, thanks!