Transfer Case Adventure -
  • 1 Post By JeeperDon
  • 2 Post By bpounds
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post #1 of 6 Old 06-11-2017, 02:57 PM Thread Starter
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1993 YJ Wrangler 
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Transfer Case Adventure

Hello everyone, I hope all is well. I have been having a loud noise coming from underneath my jeep when i up shift, loudest shifting to 1st from a stop and from 1st to 2nd. It has started to make the sound up shifting into higher gears lately although not as loud. Took it to a shop i trust they tell me the transfer case needs to be replaced (probably). They said the chain was slapping and that is what the noise shifting is coming from, and that the mount is broken because they can jiggle the transfer case. I asked if fixing the mount would remedy the problem they said no, they think there is something wrong with the case its self. Changing out the thing seems pretty simple, however finding a replacement is a little daunting. I don't know where to look to see what kind of case i have, i'm pretty sure it's the M231 as i have a 4 cylinder standard 5 speed. I'm a poor college student and need to know what vehicle i can pull one of these out of in a yard or find someone in the Midwest parting out their ride. Does anyone know of other vehicles i can pull a transfer case out of to switch into mine? Or how i can diagnose what is exactly wrong and try to fix it my self, or is it even worth it? (i have little to know experience with taking apart, fixing, and putting back together mechanical things...yet). I did find one on a site for 600, should i try and get that one?

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post #2 of 6 Old 06-11-2017, 03:04 PM
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I'm going to assume you are in 2WD when this happens?
I'm pretty sure the chain is disengaged when in 2WD and shouldn't be turning, let alone slapping.
Is it a grinding that you can feel through the shifter when you are moving it to engage 1st and then 2nd gears?
Does it make the noise when you are in gear and driving? or just during the shift?
Can you better describe the noise? can you make a video?

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post #3 of 6 Old 06-11-2017, 05:08 PM
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With it in 2wd, crawl under and see if you can turn the front drive shaft by hand. If so, your axle CAD is working, so in 2wd nothing is driving the chain. Then Dred is right, it's likely NOT the chain. If you can not turn the driveshaft by hand in 2wd, then the axle CAD may be engaged and is driving the driveshaft and the chain all the time, which could make chain noise. In either case, answer his Q's about more details, and let us know if the DS can be turned.
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post #4 of 6 Old 06-12-2017, 06:00 AM
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If it comes down to the chain, or a T-Case rebuild it is certainly a DIY. A new chain runs you $70 and unless the inside is completely ruined you may be able to get away with just that. Obviously finish the troubleshooting mentioned above first.
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post #5 of 6 Old 06-12-2017, 08:38 AM
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1992 YJ Wrangler 
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I cannot help diagnose problem, but having just completed a t-case swap, I can say that it takes little mechanical skill to replace your t-case. There is a red stamp on the back side of t-case which will tell you model. It should read NP 231 J. The main trick is to get a t-case for your size engine and manual tranny, to make sure spline count and length of shafts match. I found one at our local jeep salvage yard for $250. Good luck!
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post #6 of 6 Old 06-12-2017, 08:45 AM
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Originally Posted by Gypsy_Botanist View Post
...loudest shifting to 1st from a stop and from 1st to 2nd.
I don't understand how this could possibly be a transfer case problem. Nothing behind the clutch is turning when you shift while stopped.

And why would a shop advise replacing a transfer case, instead of a simple repair?

I smell a rotten shop rat.
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repair , replacement , transfer case

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