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Unread 12-15-2009, 07:09 AM   #1
eric411420
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1994 YJ Wrangler 
 
Join Date: Feb 2009
Location: Arizona
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Transfer Case Expert needed! NP231j 231

I have searched and searched for a long time and can't find an answer to a few of my questions.

I have a 94 YJ, 4.0, Manual trans, NP231j.

I noticed a clicking noise upon deceleration regardless of whether the clutch is in or out, trans in gear or neutral, doesn't matter. It makes the clicking in all those situations. It is vehicle speed dependent. I would roughly say that I have to be moving 25-30 mph before it will make the noise (I want to stress that it SEEMS that is the case but it is possible that I can't hear it at lower speeds). HERE, is what should be most helpful; If I put the Transfer case in Neutral, put the transmission IN GEAR (5th yields the best results) with the engine running I can hear it really well. I crawled under it and stethescoped the trans and the tcase in every spot possible and I have located the area that the noise is most prevalent. It is at the bottom of the case about an inch or so from the detent plunger/spring cap, toward the centerline of the case. I have taken the case apart for inspection and I have not found anything that is obviously wrong. PLEASE HELP!

I have some other questions relating to this issue but I don't want to get this thread sidetracked. I also think that my other questions are such that others could benefit from the answers greatly in the future so I am going to post them in a separate thread. If you see that, just realize that I am not over-posting the same thing. I am doing it to hopefully help others in their future searches as it would have been extremely useful info to me.

Thanks in advance!

Eric

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Unread 12-15-2009, 09:02 AM   #2
eric411420
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I also meant to say that there is no sign of the chain contacting the case as well. What parts are moving inside the case when it's in neutral with the trans in gear? I have dana 44's and manual hubs. I am correct that vacuum issues only apply to the stock diff and not the tcase? The P.O. installed an SYE but also left out the magnet and detent plunger spring. I now don't trust much in this case.
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Unread 12-15-2009, 09:14 AM   #3
TSEJEEPERS
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Are you sure the noise is coming from the transfer case and not the driveshaft? Maybe you have a u joint going out.
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Unread 12-15-2009, 10:15 AM   #4
rosco_dog
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1990 YJ Wrangler 
 
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Quote:
Originally Posted by eric411420 View Post
HERE, is what should be most helpful; If I put the Transfer case in Neutral, put the transmission IN GEAR (5th yields the best results) with the engine running I can hear it really well.
did you reinstall a spring? it's there to keep the shift fork in the right spot. this might be your problem. I'm assuming the above test was done with the jeep parked and not driving? So that would rule out ujoints.
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Unread 12-15-2009, 01:12 PM   #5
eric411420
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Quote:
Originally Posted by rosco_dog View Post
did you reinstall a spring? it's there to keep the shift fork in the right spot. this might be your problem. I'm assuming the above test was done with the jeep parked and not driving? So that would rule out ujoints.
The spring is definitely in there and you are correct, the jeep was stationary. The rear shaft, cv and u-joints are new and it was just balanced.

What is in motion inside the tcase when it is in neutral but the trans is in gear and rotating? The only thing I have not taken out is the planetary gear drive. I can grab it and there is a little play. How much play is normal?
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Unread 12-15-2009, 11:33 PM   #6
rosco_dog
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i had the same problem once, i sold the jeep before i could figure it out though. i sent you a pm.
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