T-Case out of an Automatic vs Manual

Imagineer

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Can anyone tell me if the stock transfer case out of a 2000 TJ 2.5l with an automatic transmission will fit a 1997 TJ 2.5l with a manual transmission?

I'm having a heck of a time finding a replacement transfer case and think I found one, but it's out of an automatic Jeep.
 
The input shaft lengths are different, the input shaft length of the tcase configured for an automatic transmission is longer. The input shaft from your existing tcase could be swapped into the new tcase.
 
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Thanks. I expected there might be some part swapping required. I'm still not sure if I should pick up this replacement t-case though as I'm not sure the input shaft on the original transfer case is still intact.

Obviously I know little, if anything about the workings of a NP231, but I do know that when I pull the lever to put mine into 4wd HI & let out the clutch, it makes a horrible gear grinding noise and the Jeep doesn't move.

I don't know what part (or parts) may have grenaded to cause that noise. What are the chances the input shaft failed and is the culprit?

Should I also be concerned about spline count? I've read that the NP231 is available with 21 and 23 spline input shafts.
 
Based on that, the problem may only be that the transfer case shift linkage has slipped out of adjustment. There's only a single bolt that holds the shift linkage in adjustment so when the shift rod the bolt is supposed to hold slips, you can't shift the tcase all the way into 4Hi or 4Lo.

The bolt that holds the shift rod in adjustment is circled in red. It connects to a lever on the transfer case which is what shifts the tcase between its gears. You can use a pair of pliers to shift it manually to test 4Hi to see if it still grinds. Have a helper try to shift into 4Hi so you can see which way that lever is supposed to move then use the pliers to shift it where it will click into place once it is in 4Hi. You can move it back into 2WD with the pliers too.

So the odds are fair there's nothing actually wrong with the transfer case and that the shift rod just slipped out of position from its holder bracket the bolt is threaded into.

One last question... does your Jeep by any chance have aftermarket manual hubs installed on the front axle? The transfer case will grind when shifting into 4Hi while you're driving if the hubs are unlocked.

transfer case linkage.jpg
 
Imagineer said:
Can anyone tell me if the stock transfer case out of a 2000 TJ 2.5l with an automatic transmission will fit a 1997 TJ 2.5l with a manual transmission?

I'm having a heck of a time finding a replacement transfer case and think I found one, but it's out of an automatic Jeep.
Click to expand...

Oddly, the 2.5 30RH auto has the same case input shaft and length as the 4.0 32RH auto. It is not the smaller spline count that the manual uses. You could easily swap them as suggested though.
 
Ok, thanks to the holiday, I actually got a day off and was able to look into the transfer case linkage on the Jeep. It's plenty rusty, but moves fine. I drove it around my back field and experimented with the 4 wheel drive. Maybe there's a smart person out there who can diagnose this...

While stopped, if I pull it into 4WH in an "aggressive manner" (basically, yank the snot out of the lever), the 4 wheel drive seems to work. It's noisy but works. After a few hundred feet or so, it seems to slip out of 4wd, the grinding noise starts and the jeep stops moving.

If I pull it into 4WH with less force on the lever, it doesn't engage and grinds when I let out the clutch.

If I perform the same aggressive engagement while rolling, it seems to stay in 4WH a little longer, but eventually slips out and starts to grind.

If I move the transfer lever over and pull up just a touch more (as if I we going for 4 wheel low), the transfer case ends up in neutral. Where I mention just a touch more, I mean a tiny amount of movement and it's no longer grinding and is in neutral.

4WL works fine and doesn't slip at all. It's actually a little less noisy than 4WH.

Are there any other 'experiments' than can be done to try and diagnose the root of the problem?

I'll also add that the 4 wheel drive indicator light on the dash doesn't light up.
 
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Not yet. I wasn't able to get the last piece of the linkage disconnected from the lever on the transfer case. I wedged a big flat screw driver between the part and the lever and leaned on it with some force. I didn't want to break anything so I gave up. Is there a trick to separating this connection (there's a green plastic bushing between the parts)?

If everything is working correctly, when I shift the t-case manually (with the linkage disconnected), is there a spring loaded detent at each of the positions (2H, 4H, N, 4L)?
 
Any pearls of wisdom for separating the linkage from the the lever coming out of the t-case? Does the plastic bushing get destroyed in the process?
 
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